diff options
Diffstat (limited to '5020_BMQ-and-PDS-io-scheduler-v5.12-r1.patch')
| -rw-r--r-- | 5020_BMQ-and-PDS-io-scheduler-v5.12-r1.patch | 9785 |
1 files changed, 9785 insertions, 0 deletions
diff --git a/5020_BMQ-and-PDS-io-scheduler-v5.12-r1.patch b/5020_BMQ-and-PDS-io-scheduler-v5.12-r1.patch new file mode 100644 index 00000000..1060af57 --- /dev/null +++ b/5020_BMQ-and-PDS-io-scheduler-v5.12-r1.patch @@ -0,0 +1,9785 @@ +diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt +index 04545725f187..d560166b0cf1 100644 +--- a/Documentation/admin-guide/kernel-parameters.txt ++++ b/Documentation/admin-guide/kernel-parameters.txt +@@ -4725,6 +4725,12 @@ + + sbni= [NET] Granch SBNI12 leased line adapter + ++ sched_timeslice= ++ [KNL] Time slice in us for BMQ/PDS scheduler. ++ Format: <int> (must be >= 1000) ++ Default: 4000 ++ See Documentation/scheduler/sched-BMQ.txt ++ + sched_debug [KNL] Enables verbose scheduler debug messages. + + schedstats= [KNL,X86] Enable or disable scheduled statistics. +diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst +index 1d56a6b73a4e..e08ffb857277 100644 +--- a/Documentation/admin-guide/sysctl/kernel.rst ++++ b/Documentation/admin-guide/sysctl/kernel.rst +@@ -1515,3 +1515,13 @@ is 10 seconds. + + The softlockup threshold is (``2 * watchdog_thresh``). Setting this + tunable to zero will disable lockup detection altogether. ++ ++yield_type: ++=========== ++ ++BMQ/PDS CPU scheduler only. This determines what type of yield calls ++to sched_yield will perform. ++ ++ 0 - No yield. ++ 1 - Deboost and requeue task. (default) ++ 2 - Set run queue skip task. +diff --git a/Documentation/scheduler/sched-BMQ.txt b/Documentation/scheduler/sched-BMQ.txt +new file mode 100644 +index 000000000000..05c84eec0f31 +--- /dev/null ++++ b/Documentation/scheduler/sched-BMQ.txt +@@ -0,0 +1,110 @@ ++ BitMap queue CPU Scheduler ++ -------------------------- ++ ++CONTENT ++======== ++ ++ Background ++ Design ++ Overview ++ Task policy ++ Priority management ++ BitMap Queue ++ CPU Assignment and Migration ++ ++ ++Background ++========== ++ ++BitMap Queue CPU scheduler, referred to as BMQ from here on, is an evolution ++of previous Priority and Deadline based Skiplist multiple queue scheduler(PDS), ++and inspired by Zircon scheduler. The goal of it is to keep the scheduler code ++simple, while efficiency and scalable for interactive tasks, such as desktop, ++movie playback and gaming etc. ++ ++Design ++====== ++ ++Overview ++-------- ++ ++BMQ use per CPU run queue design, each CPU(logical) has it's own run queue, ++each CPU is responsible for scheduling the tasks that are putting into it's ++run queue. ++ ++The run queue is a set of priority queues. Note that these queues are fifo ++queue for non-rt tasks or priority queue for rt tasks in data structure. See ++BitMap Queue below for details. BMQ is optimized for non-rt tasks in the fact ++that most applications are non-rt tasks. No matter the queue is fifo or ++priority, In each queue is an ordered list of runnable tasks awaiting execution ++and the data structures are the same. When it is time for a new task to run, ++the scheduler simply looks the lowest numbered queueue that contains a task, ++and runs the first task from the head of that queue. And per CPU idle task is ++also in the run queue, so the scheduler can always find a task to run on from ++its run queue. ++ ++Each task will assigned the same timeslice(default 4ms) when it is picked to ++start running. Task will be reinserted at the end of the appropriate priority ++queue when it uses its whole timeslice. When the scheduler selects a new task ++from the priority queue it sets the CPU's preemption timer for the remainder of ++the previous timeslice. When that timer fires the scheduler will stop execution ++on that task, select another task and start over again. ++ ++If a task blocks waiting for a shared resource then it's taken out of its ++priority queue and is placed in a wait queue for the shared resource. When it ++is unblocked it will be reinserted in the appropriate priority queue of an ++eligible CPU. ++ ++Task policy ++----------- ++ ++BMQ supports DEADLINE, FIFO, RR, NORMAL, BATCH and IDLE task policy like the ++mainline CFS scheduler. But BMQ is heavy optimized for non-rt task, that's ++NORMAL/BATCH/IDLE policy tasks. Below is the implementation detail of each ++policy. ++ ++DEADLINE ++ It is squashed as priority 0 FIFO task. ++ ++FIFO/RR ++ All RT tasks share one single priority queue in BMQ run queue designed. The ++complexity of insert operation is O(n). BMQ is not designed for system runs ++with major rt policy tasks. ++ ++NORMAL/BATCH/IDLE ++ BATCH and IDLE tasks are treated as the same policy. They compete CPU with ++NORMAL policy tasks, but they just don't boost. To control the priority of ++NORMAL/BATCH/IDLE tasks, simply use nice level. ++ ++ISO ++ ISO policy is not supported in BMQ. Please use nice level -20 NORMAL policy ++task instead. ++ ++Priority management ++------------------- ++ ++RT tasks have priority from 0-99. For non-rt tasks, there are three different ++factors used to determine the effective priority of a task. The effective ++priority being what is used to determine which queue it will be in. ++ ++The first factor is simply the task’s static priority. Which is assigned from ++task's nice level, within [-20, 19] in userland's point of view and [0, 39] ++internally. ++ ++The second factor is the priority boost. This is a value bounded between ++[-MAX_PRIORITY_ADJ, MAX_PRIORITY_ADJ] used to offset the base priority, it is ++modified by the following cases: ++ ++*When a thread has used up its entire timeslice, always deboost its boost by ++increasing by one. ++*When a thread gives up cpu control(voluntary or non-voluntary) to reschedule, ++and its switch-in time(time after last switch and run) below the thredhold ++based on its priority boost, will boost its boost by decreasing by one buti is ++capped at 0 (won’t go negative). ++ ++The intent in this system is to ensure that interactive threads are serviced ++quickly. These are usually the threads that interact directly with the user ++and cause user-perceivable latency. These threads usually do little work and ++spend most of their time blocked awaiting another user event. So they get the ++priority boost from unblocking while background threads that do most of the ++processing receive the priority penalty for using their entire timeslice. +diff --git a/fs/proc/base.c b/fs/proc/base.c +index 3851bfcdba56..732636ac3fd3 100644 +--- a/fs/proc/base.c ++++ b/fs/proc/base.c +@@ -476,7 +476,7 @@ static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns, + seq_puts(m, "0 0 0\n"); + else + seq_printf(m, "%llu %llu %lu\n", +- (unsigned long long)task->se.sum_exec_runtime, ++ (unsigned long long)tsk_seruntime(task), + (unsigned long long)task->sched_info.run_delay, + task->sched_info.pcount); + +diff --git a/include/asm-generic/resource.h b/include/asm-generic/resource.h +index 8874f681b056..59eb72bf7d5f 100644 +--- a/include/asm-generic/resource.h ++++ b/include/asm-generic/resource.h +@@ -23,7 +23,7 @@ + [RLIMIT_LOCKS] = { RLIM_INFINITY, RLIM_INFINITY }, \ + [RLIMIT_SIGPENDING] = { 0, 0 }, \ + [RLIMIT_MSGQUEUE] = { MQ_BYTES_MAX, MQ_BYTES_MAX }, \ +- [RLIMIT_NICE] = { 0, 0 }, \ ++ [RLIMIT_NICE] = { 30, 30 }, \ + [RLIMIT_RTPRIO] = { 0, 0 }, \ + [RLIMIT_RTTIME] = { RLIM_INFINITY, RLIM_INFINITY }, \ + } +diff --git a/include/linux/sched.h b/include/linux/sched.h +index ef00bb22164c..2290806d8af2 100644 +--- a/include/linux/sched.h ++++ b/include/linux/sched.h +@@ -35,6 +35,7 @@ + #include <linux/rseq.h> + #include <linux/seqlock.h> + #include <linux/kcsan.h> ++#include <linux/skip_list.h> + #include <asm/kmap_size.h> + + /* task_struct member predeclarations (sorted alphabetically): */ +@@ -670,12 +671,18 @@ struct task_struct { + unsigned int ptrace; + + #ifdef CONFIG_SMP +- int on_cpu; + struct __call_single_node wake_entry; ++#endif ++#if defined(CONFIG_SMP) || defined(CONFIG_SCHED_ALT) ++ int on_cpu; ++#endif ++ ++#ifdef CONFIG_SMP + #ifdef CONFIG_THREAD_INFO_IN_TASK + /* Current CPU: */ + unsigned int cpu; + #endif ++#ifndef CONFIG_SCHED_ALT + unsigned int wakee_flips; + unsigned long wakee_flip_decay_ts; + struct task_struct *last_wakee; +@@ -689,6 +696,7 @@ struct task_struct { + */ + int recent_used_cpu; + int wake_cpu; ++#endif /* !CONFIG_SCHED_ALT */ + #endif + int on_rq; + +@@ -697,13 +705,33 @@ struct task_struct { + int normal_prio; + unsigned int rt_priority; + ++#ifdef CONFIG_SCHED_ALT ++ u64 last_ran; ++ s64 time_slice; ++#ifdef CONFIG_SCHED_BMQ ++ int boost_prio; ++ int bmq_idx; ++ struct list_head bmq_node; ++#endif /* CONFIG_SCHED_BMQ */ ++#ifdef CONFIG_SCHED_PDS ++ u64 deadline; ++ u64 priodl; ++ /* skip list level */ ++ int sl_level; ++ /* skip list node */ ++ struct skiplist_node sl_node; ++#endif /* CONFIG_SCHED_PDS */ ++ /* sched_clock time spent running */ ++ u64 sched_time; ++#else /* !CONFIG_SCHED_ALT */ + const struct sched_class *sched_class; + struct sched_entity se; + struct sched_rt_entity rt; ++ struct sched_dl_entity dl; ++#endif + #ifdef CONFIG_CGROUP_SCHED + struct task_group *sched_task_group; + #endif +- struct sched_dl_entity dl; + + #ifdef CONFIG_UCLAMP_TASK + /* +@@ -1388,6 +1416,15 @@ struct task_struct { + */ + }; + ++#ifdef CONFIG_SCHED_ALT ++#define tsk_seruntime(t) ((t)->sched_time) ++/* replace the uncertian rt_timeout with 0UL */ ++#define tsk_rttimeout(t) (0UL) ++#else /* CFS */ ++#define tsk_seruntime(t) ((t)->se.sum_exec_runtime) ++#define tsk_rttimeout(t) ((t)->rt.timeout) ++#endif /* !CONFIG_SCHED_ALT */ ++ + static inline struct pid *task_pid(struct task_struct *task) + { + return task->thread_pid; +diff --git a/include/linux/sched/deadline.h b/include/linux/sched/deadline.h +index 1aff00b65f3c..179d77c8360e 100644 +--- a/include/linux/sched/deadline.h ++++ b/include/linux/sched/deadline.h +@@ -1,5 +1,24 @@ + /* SPDX-License-Identifier: GPL-2.0 */ + ++#ifdef CONFIG_SCHED_ALT ++ ++static inline int dl_task(struct task_struct *p) ++{ ++ return 0; ++} ++ ++#ifdef CONFIG_SCHED_BMQ ++#define __tsk_deadline(p) (0UL) ++#endif ++ ++#ifdef CONFIG_SCHED_PDS ++#define __tsk_deadline(p) ((p)->priodl) ++#endif ++ ++#else ++ ++#define __tsk_deadline(p) ((p)->dl.deadline) ++ + /* + * SCHED_DEADLINE tasks has negative priorities, reflecting + * the fact that any of them has higher prio than RT and +@@ -19,6 +38,7 @@ static inline int dl_task(struct task_struct *p) + { + return dl_prio(p->prio); + } ++#endif /* CONFIG_SCHED_ALT */ + + static inline bool dl_time_before(u64 a, u64 b) + { +diff --git a/include/linux/sched/prio.h b/include/linux/sched/prio.h +index ab83d85e1183..4d4f92bffeea 100644 +--- a/include/linux/sched/prio.h ++++ b/include/linux/sched/prio.h +@@ -18,6 +18,14 @@ + #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH) + #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2) + ++/* +/- priority levels from the base priority */ ++#ifdef CONFIG_SCHED_BMQ ++#define MAX_PRIORITY_ADJ 7 ++#endif ++#ifdef CONFIG_SCHED_PDS ++#define MAX_PRIORITY_ADJ 0 ++#endif ++ + /* + * Convert user-nice values [ -20 ... 0 ... 19 ] + * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], +diff --git a/include/linux/sched/rt.h b/include/linux/sched/rt.h +index e5af028c08b4..0a7565d0d3cf 100644 +--- a/include/linux/sched/rt.h ++++ b/include/linux/sched/rt.h +@@ -24,8 +24,10 @@ static inline bool task_is_realtime(struct task_struct *tsk) + + if (policy == SCHED_FIFO || policy == SCHED_RR) + return true; ++#ifndef CONFIG_SCHED_ALT + if (policy == SCHED_DEADLINE) + return true; ++#endif + return false; + } + +diff --git a/include/linux/skip_list.h b/include/linux/skip_list.h +new file mode 100644 +index 000000000000..637c83ecbd6b +--- /dev/null ++++ b/include/linux/skip_list.h +@@ -0,0 +1,175 @@ ++/* ++ * Copyright (C) 2016 Alfred Chen. ++ * ++ * Code based on Con Kolivas's skip list implementation for BFS, and ++ * which is based on example originally by William Pugh. ++ * ++ * Skip Lists are a probabilistic alternative to balanced trees, as ++ * described in the June 1990 issue of CACM and were invented by ++ * William Pugh in 1987. ++ * ++ * A couple of comments about this implementation: ++ * ++ * This file only provides a infrastructure of skip list. ++ * ++ * skiplist_node is embedded into container data structure, to get rid ++ * the dependency of kmalloc/kfree operation in scheduler code. ++ * ++ * A customized search function should be defined using DEFINE_SKIPLIST_INSERT ++ * macro and be used for skip list insert operation. ++ * ++ * Random Level is also not defined in this file, instead, it should be ++ * customized implemented and set to node->level then pass to the customized ++ * skiplist_insert function. ++ * ++ * Levels start at zero and go up to (NUM_SKIPLIST_LEVEL -1) ++ * ++ * NUM_SKIPLIST_LEVEL in this implementation is 8 instead of origin 16, ++ * considering that there will be 256 entries to enable the top level when using ++ * random level p=0.5, and that number is more than enough for a run queue usage ++ * in a scheduler usage. And it also help to reduce the memory usage of the ++ * embedded skip list node in task_struct to about 50%. ++ * ++ * The insertion routine has been implemented so as to use the ++ * dirty hack described in the CACM paper: if a random level is ++ * generated that is more than the current maximum level, the ++ * current maximum level plus one is used instead. ++ * ++ * BFS Notes: In this implementation of skiplists, there are bidirectional ++ * next/prev pointers and the insert function returns a pointer to the actual ++ * node the value is stored. The key here is chosen by the scheduler so as to ++ * sort tasks according to the priority list requirements and is no longer used ++ * by the scheduler after insertion. The scheduler lookup, however, occurs in ++ * O(1) time because it is always the first item in the level 0 linked list. ++ * Since the task struct stores a copy of the node pointer upon skiplist_insert, ++ * it can also remove it much faster than the original implementation with the ++ * aid of prev<->next pointer manipulation and no searching. ++ */ ++#ifndef _LINUX_SKIP_LIST_H ++#define _LINUX_SKIP_LIST_H ++ ++#include <linux/kernel.h> ++ ++#define NUM_SKIPLIST_LEVEL (4) ++ ++struct skiplist_node { ++ int level; /* Levels in this node */ ++ struct skiplist_node *next[NUM_SKIPLIST_LEVEL]; ++ struct skiplist_node *prev[NUM_SKIPLIST_LEVEL]; ++}; ++ ++#define SKIPLIST_NODE_INIT(name) { 0,\ ++ {&name, &name, &name, &name},\ ++ {&name, &name, &name, &name},\ ++ } ++ ++/** ++ * INIT_SKIPLIST_NODE -- init a skiplist_node, expecially for header ++ * @node: the skip list node to be inited. ++ */ ++static inline void INIT_SKIPLIST_NODE(struct skiplist_node *node) ++{ ++ int i; ++ ++ node->level = 0; ++ for (i = 0; i < NUM_SKIPLIST_LEVEL; i++) { ++ WRITE_ONCE(node->next[i], node); ++ node->prev[i] = node; ++ } ++} ++ ++/** ++ * skiplist_entry - get the struct for this entry ++ * @ptr: the &struct skiplist_node pointer. ++ * @type: the type of the struct this is embedded in. ++ * @member: the name of the skiplist_node within the struct. ++ */ ++#define skiplist_entry(ptr, type, member) \ ++ container_of(ptr, type, member) ++ ++/** ++ * DEFINE_SKIPLIST_INSERT_FUNC -- macro to define a customized skip list insert ++ * function, which takes two parameters, first one is the header node of the ++ * skip list, second one is the skip list node to be inserted ++ * @func_name: the customized skip list insert function name ++ * @search_func: the search function to be used, which takes two parameters, ++ * 1st one is the itrator of skiplist_node in the list, the 2nd is the skip list ++ * node to be inserted, the function should return true if search should be ++ * continued, otherwise return false. ++ * Returns 1 if @node is inserted as the first item of skip list at level zero, ++ * otherwise 0 ++ */ ++#define DEFINE_SKIPLIST_INSERT_FUNC(func_name, search_func)\ ++static inline int func_name(struct skiplist_node *head, struct skiplist_node *node)\ ++{\ ++ struct skiplist_node *p, *q;\ ++ unsigned int k = head->level;\ ++ unsigned int l = node->level;\ ++\ ++ p = head;\ ++ if (l > k) {\ ++ l = node->level = ++head->level;\ ++\ ++ node->next[l] = head;\ ++ node->prev[l] = head;\ ++ head->next[l] = node;\ ++ head->prev[l] = node;\ ++\ ++ do {\ ++ while (q = p->next[k], q != head && search_func(q, node))\ ++ p = q;\ ++\ ++ node->prev[k] = p;\ ++ node->next[k] = q;\ ++ q->prev[k] = node;\ ++ p->next[k] = node;\ ++ } while (k--);\ ++\ ++ return (p == head);\ ++ }\ ++\ ++ while (k > l) {\ ++ while (q = p->next[k], q != head && search_func(q, node))\ ++ p = q;\ ++ k--;\ ++ }\ ++\ ++ do {\ ++ while (q = p->next[k], q != head && search_func(q, node))\ ++ p = q;\ ++\ ++ node->prev[k] = p;\ ++ node->next[k] = q;\ ++ q->prev[k] = node;\ ++ p->next[k] = node;\ ++ } while (k--);\ ++\ ++ return (p == head);\ ++} ++ ++/** ++ * skiplist_del_init -- delete skip list node from a skip list and reset it's ++ * init state ++ * @head: the header node of the skip list to be deleted from. ++ * @node: the skip list node to be deleted, the caller need to ensure @node is ++ * in skip list which @head represent. ++ * Returns 1 if @node is the first item of skip level at level zero, otherwise 0 ++ */ ++static inline int ++skiplist_del_init(struct skiplist_node *head, struct skiplist_node *node) ++{ ++ unsigned int i, level = node->level; ++ ++ for (i = 0; i <= level; i++) { ++ node->prev[i]->next[i] = node->next[i]; ++ node->next[i]->prev[i] = node->prev[i]; ++ } ++ if (level == head->level && level) { ++ while (head->next[level] == head && level) ++ level--; ++ head->level = level; ++ } ++ ++ return (node->prev[0] == head); ++} ++#endif /* _LINUX_SKIP_LIST_H */ +diff --git a/init/Kconfig b/init/Kconfig +index 5f5c776ef192..2529408ce0b5 100644 +--- a/init/Kconfig ++++ b/init/Kconfig +@@ -779,9 +779,39 @@ config GENERIC_SCHED_CLOCK + + menu "Scheduler features" + ++menuconfig SCHED_ALT ++ bool "Alternative CPU Schedulers" ++ default y ++ help ++ This feature enable alternative CPU scheduler" ++ ++if SCHED_ALT ++ ++choice ++ prompt "Alternative CPU Scheduler" ++ default SCHED_BMQ ++ ++config SCHED_BMQ ++ bool "BMQ CPU scheduler" ++ help ++ The BitMap Queue CPU scheduler for excellent interactivity and ++ responsiveness on the desktop and solid scalability on normal ++ hardware and commodity servers. ++ ++config SCHED_PDS ++ bool "PDS CPU scheduler" ++ help ++ The Priority and Deadline based Skip list multiple queue CPU ++ Scheduler. ++ ++endchoice ++ ++endif ++ + config UCLAMP_TASK + bool "Enable utilization clamping for RT/FAIR tasks" + depends on CPU_FREQ_GOV_SCHEDUTIL ++ depends on !SCHED_ALT + help + This feature enables the scheduler to track the clamped utilization + of each CPU based on RUNNABLE tasks scheduled on that CPU. +@@ -867,6 +897,7 @@ config NUMA_BALANCING + depends on ARCH_SUPPORTS_NUMA_BALANCING + depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY + depends on SMP && NUMA && MIGRATION ++ depends on !SCHED_ALT + help + This option adds support for automatic NUMA aware memory/task placement. + The mechanism is quite primitive and is based on migrating memory when +@@ -959,6 +990,7 @@ config FAIR_GROUP_SCHED + depends on CGROUP_SCHED + default CGROUP_SCHED + ++if !SCHED_ALT + config CFS_BANDWIDTH + bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED" + depends on FAIR_GROUP_SCHED +@@ -981,6 +1013,7 @@ config RT_GROUP_SCHED + realtime bandwidth for them. + See Documentation/scheduler/sched-rt-group.rst for more information. + ++endif #!SCHED_ALT + endif #CGROUP_SCHED + + config UCLAMP_TASK_GROUP +@@ -1210,6 +1243,7 @@ config CHECKPOINT_RESTORE + + config SCHED_AUTOGROUP + bool "Automatic process group scheduling" ++ depends on !SCHED_ALT + select CGROUPS + select CGROUP_SCHED + select FAIR_GROUP_SCHED +diff --git a/init/init_task.c b/init/init_task.c +index 3711cdaafed2..47f57d2cc488 100644 +--- a/init/init_task.c ++++ b/init/init_task.c +@@ -75,9 +75,20 @@ struct task_struct init_task + .stack = init_stack, + .usage = REFCOUNT_INIT(2), + .flags = PF_KTHREAD, ++#ifdef CONFIG_SCHED_BMQ ++ .prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, ++ .static_prio = DEFAULT_PRIO, ++ .normal_prio = DEFAULT_PRIO + MAX_PRIORITY_ADJ, ++#endif ++#ifdef CONFIG_SCHED_PDS ++ .prio = MAX_RT_PRIO, ++ .static_prio = DEFAULT_PRIO, ++ .normal_prio = MAX_RT_PRIO, ++#else + .prio = MAX_PRIO - 20, + .static_prio = MAX_PRIO - 20, + .normal_prio = MAX_PRIO - 20, ++#endif + .policy = SCHED_NORMAL, + .cpus_ptr = &init_task.cpus_mask, + .cpus_mask = CPU_MASK_ALL, +@@ -87,6 +98,19 @@ struct task_struct init_task + .restart_block = { + .fn = do_no_restart_syscall, + }, ++#ifdef CONFIG_SCHED_ALT ++#ifdef CONFIG_SCHED_BMQ ++ .boost_prio = 0, ++ .bmq_idx = 15, ++ .bmq_node = LIST_HEAD_INIT(init_task.bmq_node), ++#endif ++#ifdef CONFIG_SCHED_PDS ++ .deadline = 0, ++ .sl_level = 0, ++ .sl_node = SKIPLIST_NODE_INIT(init_task.sl_node), ++#endif ++ .time_slice = HZ, ++#else + .se = { + .group_node = LIST_HEAD_INIT(init_task.se.group_node), + }, +@@ -94,6 +118,7 @@ struct task_struct init_task + .run_list = LIST_HEAD_INIT(init_task.rt.run_list), + .time_slice = RR_TIMESLICE, + }, ++#endif + .tasks = LIST_HEAD_INIT(init_task.tasks), + #ifdef CONFIG_SMP + .pushable_tasks = PLIST_NODE_INIT(init_task.pushable_tasks, MAX_PRIO), +diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c +index 5258b68153e0..3eb670b1bb76 100644 +--- a/kernel/cgroup/cpuset.c ++++ b/kernel/cgroup/cpuset.c +@@ -636,7 +636,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial) + return ret; + } + +-#ifdef CONFIG_SMP ++#if defined(CONFIG_SMP) && !defined(CONFIG_SCHED_ALT) + /* + * Helper routine for generate_sched_domains(). + * Do cpusets a, b have overlapping effective cpus_allowed masks? +@@ -1032,7 +1032,7 @@ static void rebuild_sched_domains_locked(void) + /* Have scheduler rebuild the domains */ + partition_and_rebuild_sched_domains(ndoms, doms, attr); + } +-#else /* !CONFIG_SMP */ ++#else /* !CONFIG_SMP || CONFIG_SCHED_ALT */ + static void rebuild_sched_domains_locked(void) + { + } +diff --git a/kernel/delayacct.c b/kernel/delayacct.c +index 27725754ac99..769d773c7182 100644 +--- a/kernel/delayacct.c ++++ b/kernel/delayacct.c +@@ -106,7 +106,7 @@ int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) + */ + t1 = tsk->sched_info.pcount; + t2 = tsk->sched_info.run_delay; +- t3 = tsk->se.sum_exec_runtime; ++ t3 = tsk_seruntime(tsk); + + d->cpu_count += t1; + +diff --git a/kernel/exit.c b/kernel/exit.c +index 04029e35e69a..5ee0dc0b9175 100644 +--- a/kernel/exit.c ++++ b/kernel/exit.c +@@ -122,7 +122,7 @@ static void __exit_signal(struct task_struct *tsk) + sig->curr_target = next_thread(tsk); + } + +- add_device_randomness((const void*) &tsk->se.sum_exec_runtime, ++ add_device_randomness((const void*) &tsk_seruntime(tsk), + sizeof(unsigned long long)); + + /* +@@ -143,7 +143,7 @@ static void __exit_signal(struct task_struct *tsk) + sig->inblock += task_io_get_inblock(tsk); + sig->oublock += task_io_get_oublock(tsk); + task_io_accounting_add(&sig->ioac, &tsk->ioac); +- sig->sum_sched_runtime += tsk->se.sum_exec_runtime; ++ sig->sum_sched_runtime += tsk_seruntime(tsk); + sig->nr_threads--; + __unhash_process(tsk, group_dead); + write_sequnlock(&sig->stats_lock); +diff --git a/kernel/livepatch/transition.c b/kernel/livepatch/transition.c +index f6310f848f34..4176ad070bc9 100644 +--- a/kernel/livepatch/transition.c ++++ b/kernel/livepatch/transition.c +@@ -306,7 +306,11 @@ static bool klp_try_switch_task(struct task_struct *task) + */ + rq = task_rq_lock(task, &flags); + ++#ifdef CONFIG_SCHED_ALT ++ if (task_running(task) && task != current) { ++#else + if (task_running(rq, task) && task != current) { ++#endif + snprintf(err_buf, STACK_ERR_BUF_SIZE, + "%s: %s:%d is running\n", __func__, task->comm, + task->pid); +diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c +index 48fff6437901..40506d5b5a2e 100644 +--- a/kernel/locking/rtmutex.c ++++ b/kernel/locking/rtmutex.c +@@ -227,15 +227,19 @@ static inline bool unlock_rt_mutex_safe(struct rt_mutex *lock, + * Only use with rt_mutex_waiter_{less,equal}() + */ + #define task_to_waiter(p) \ +- &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = (p)->dl.deadline } ++ &(struct rt_mutex_waiter){ .prio = (p)->prio, .deadline = __tsk_deadline(p) } + + static inline int + rt_mutex_waiter_less(struct rt_mutex_waiter *left, + struct rt_mutex_waiter *right) + { ++#ifdef CONFIG_SCHED_PDS ++ return (left->deadline < right->deadline); ++#else + if (left->prio < right->prio) + return 1; + ++#ifndef CONFIG_SCHED_BMQ + /* + * If both waiters have dl_prio(), we check the deadlines of the + * associated tasks. +@@ -244,17 +248,23 @@ rt_mutex_waiter_less(struct rt_mutex_waiter *left, + */ + if (dl_prio(left->prio)) + return dl_time_before(left->deadline, right->deadline); ++#endif + + return 0; ++#endif + } + + static inline int + rt_mutex_waiter_equal(struct rt_mutex_waiter *left, + struct rt_mutex_waiter *right) + { ++#ifdef CONFIG_SCHED_PDS ++ return (left->deadline == right->deadline); ++#else + if (left->prio != right->prio) + return 0; + ++#ifndef CONFIG_SCHED_BMQ + /* + * If both waiters have dl_prio(), we check the deadlines of the + * associated tasks. +@@ -263,8 +273,10 @@ rt_mutex_waiter_equal(struct rt_mutex_waiter *left, + */ + if (dl_prio(left->prio)) + return left->deadline == right->deadline; ++#endif + + return 1; ++#endif + } + + #define __node_2_waiter(node) \ +@@ -660,7 +672,7 @@ static int rt_mutex_adjust_prio_chain(struct task_struct *task, + * the values of the node being removed. + */ + waiter->prio = task->prio; +- waiter->deadline = task->dl.deadline; ++ waiter->deadline = __tsk_deadline(task); + + rt_mutex_enqueue(lock, waiter); + +@@ -933,7 +945,7 @@ static int task_blocks_on_rt_mutex(struct rt_mutex *lock, + waiter->task = task; + waiter->lock = lock; + waiter->prio = task->prio; +- waiter->deadline = task->dl.deadline; ++ waiter->deadline = __tsk_deadline(task); + + /* Get the top priority waiter on the lock */ + if (rt_mutex_has_waiters(lock)) +diff --git a/kernel/sched/Makefile b/kernel/sched/Makefile +index 5fc9c9b70862..eb6d7d87779f 100644 +--- a/kernel/sched/Makefile ++++ b/kernel/sched/Makefile +@@ -22,14 +22,20 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) + CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer + endif + +-obj-y += core.o loadavg.o clock.o cputime.o +-obj-y += idle.o fair.o rt.o deadline.o +-obj-y += wait.o wait_bit.o swait.o completion.o +- +-obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o topology.o stop_task.o pelt.o ++ifdef CONFIG_SCHED_ALT ++obj-y += alt_core.o alt_debug.o ++else ++obj-y += core.o ++obj-y += fair.o rt.o deadline.o ++obj-$(CONFIG_SMP) += cpudeadline.o stop_task.o + obj-$(CONFIG_SCHED_AUTOGROUP) += autogroup.o +-obj-$(CONFIG_SCHEDSTATS) += stats.o + obj-$(CONFIG_SCHED_DEBUG) += debug.o ++endif ++obj-y += loadavg.o clock.o cputime.o ++obj-y += idle.o ++obj-y += wait.o wait_bit.o swait.o completion.o ++obj-$(CONFIG_SMP) += cpupri.o pelt.o topology.o ++obj-$(CONFIG_SCHEDSTATS) += stats.o + obj-$(CONFIG_CGROUP_CPUACCT) += cpuacct.o + obj-$(CONFIG_CPU_FREQ) += cpufreq.o + obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o +diff --git a/kernel/sched/alt_core.c b/kernel/sched/alt_core.c +new file mode 100644 +index 000000000000..c85e3ccf9302 +--- /dev/null ++++ b/kernel/sched/alt_core.c +@@ -0,0 +1,7138 @@ ++/* ++ * kernel/sched/alt_core.c ++ * ++ * Core alternative kernel scheduler code and related syscalls ++ * ++ * Copyright (C) 1991-2002 Linus Torvalds ++ * ++ * 2009-08-13 Brainfuck deadline scheduling policy by Con Kolivas deletes ++ * a whole lot of those previous things. ++ * 2017-09-06 Priority and Deadline based Skip list multiple queue kernel ++ * scheduler by Alfred Chen. ++ * 2019-02-20 BMQ(BitMap Queue) kernel scheduler by Alfred Chen. ++ */ ++#define CREATE_TRACE_POINTS ++#include <trace/events/sched.h> ++#undef CREATE_TRACE_POINTS ++ ++#include "sched.h" ++ ++#include <linux/sched/rt.h> ++ ++#include <linux/context_tracking.h> ++#include <linux/compat.h> ++#include <linux/blkdev.h> ++#include <linux/delayacct.h> ++#include <linux/freezer.h> ++#include <linux/init_task.h> ++#include <linux/kprobes.h> ++#include <linux/mmu_context.h> ++#include <linux/nmi.h> ++#include <linux/profile.h> ++#include <linux/rcupdate_wait.h> ++#include <linux/security.h> ++#include <linux/syscalls.h> ++#include <linux/wait_bit.h> ++ ++#include <linux/kcov.h> ++#include <linux/scs.h> ++ ++#include <asm/switch_to.h> ++ ++#include "../workqueue_internal.h" ++#include "../../fs/io-wq.h" ++#include "../smpboot.h" ++ ++#include "pelt.h" ++#include "smp.h" ++ ++/* ++ * Export tracepoints that act as a bare tracehook (ie: have no trace event ++ * associated with them) to allow external modules to probe them. ++ */ ++EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp); ++ ++#define ALT_SCHED_VERSION "v5.12-r1" ++ ++/* rt_prio(prio) defined in include/linux/sched/rt.h */ ++#define rt_task(p) rt_prio((p)->prio) ++#define rt_policy(policy) ((policy) == SCHED_FIFO || (policy) == SCHED_RR) ++#define task_has_rt_policy(p) (rt_policy((p)->policy)) ++ ++#define STOP_PRIO (MAX_RT_PRIO - 1) ++ ++/* Default time slice is 4 in ms, can be set via kernel parameter "sched_timeslice" */ ++u64 sched_timeslice_ns __read_mostly = (4 * 1000 * 1000); ++ ++static int __init sched_timeslice(char *str) ++{ ++ int timeslice_us; ++ ++ get_option(&str, ×lice_us); ++ if (timeslice_us >= 1000) ++ sched_timeslice_ns = timeslice_us * 1000; ++ ++ return 0; ++} ++early_param("sched_timeslice", sched_timeslice); ++ ++/* Reschedule if less than this many μs left */ ++#define RESCHED_NS (100 * 1000) ++ ++/** ++ * sched_yield_type - Choose what sort of yield sched_yield will perform. ++ * 0: No yield. ++ * 1: Deboost and requeue task. (default) ++ * 2: Set rq skip task. ++ */ ++int sched_yield_type __read_mostly = 1; ++ ++#ifdef CONFIG_SMP ++static cpumask_t sched_rq_pending_mask ____cacheline_aligned_in_smp; ++ ++DEFINE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_affinity_masks); ++DEFINE_PER_CPU(cpumask_t *, sched_cpu_affinity_end_mask); ++ ++DEFINE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); ++DEFINE_PER_CPU(cpumask_t *, sched_cpu_llc_mask); ++ ++#ifdef CONFIG_SCHED_SMT ++DEFINE_STATIC_KEY_FALSE(sched_smt_present); ++EXPORT_SYMBOL_GPL(sched_smt_present); ++#endif ++ ++/* ++ * Keep a unique ID per domain (we use the first CPUs number in the cpumask of ++ * the domain), this allows us to quickly tell if two cpus are in the same cache ++ * domain, see cpus_share_cache(). ++ */ ++DEFINE_PER_CPU(int, sd_llc_id); ++#endif /* CONFIG_SMP */ ++ ++static DEFINE_MUTEX(sched_hotcpu_mutex); ++ ++DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); ++ ++#ifndef prepare_arch_switch ++# define prepare_arch_switch(next) do { } while (0) ++#endif ++#ifndef finish_arch_post_lock_switch ++# define finish_arch_post_lock_switch() do { } while (0) ++#endif ++ ++#define IDLE_WM (IDLE_TASK_SCHED_PRIO) ++ ++#ifdef CONFIG_SCHED_SMT ++static cpumask_t sched_sg_idle_mask ____cacheline_aligned_in_smp; ++#endif ++static cpumask_t sched_rq_watermark[SCHED_BITS] ____cacheline_aligned_in_smp; ++ ++#ifdef CONFIG_SCHED_BMQ ++#include "bmq_imp.h" ++#endif ++#ifdef CONFIG_SCHED_PDS ++#include "pds_imp.h" ++#endif ++ ++static inline void update_sched_rq_watermark(struct rq *rq) ++{ ++ unsigned long watermark = sched_queue_watermark(rq); ++ unsigned long last_wm = rq->watermark; ++ unsigned long i; ++ int cpu; ++ ++ /*printk(KERN_INFO "sched: watermark(%d) %d, last %d\n", ++ cpu_of(rq), watermark, last_wm);*/ ++ if (watermark == last_wm) ++ return; ++ ++ rq->watermark = watermark; ++ cpu = cpu_of(rq); ++ if (watermark < last_wm) { ++ for (i = watermark + 1; i <= last_wm; i++) ++ cpumask_andnot(&sched_rq_watermark[i], ++ &sched_rq_watermark[i], cpumask_of(cpu)); ++#ifdef CONFIG_SCHED_SMT ++ if (!static_branch_likely(&sched_smt_present)) ++ return; ++ if (IDLE_WM == last_wm) ++ cpumask_andnot(&sched_sg_idle_mask, ++ &sched_sg_idle_mask, cpu_smt_mask(cpu)); ++#endif ++ return; ++ } ++ /* last_wm < watermark */ ++ for (i = last_wm + 1; i <= watermark; i++) ++ cpumask_set_cpu(cpu, &sched_rq_watermark[i]); ++#ifdef CONFIG_SCHED_SMT ++ if (!static_branch_likely(&sched_smt_present)) ++ return; ++ if (IDLE_WM == watermark) { ++ cpumask_t tmp; ++ cpumask_and(&tmp, cpu_smt_mask(cpu), &sched_rq_watermark[IDLE_WM]); ++ if (cpumask_equal(&tmp, cpu_smt_mask(cpu))) ++ cpumask_or(&sched_sg_idle_mask, cpu_smt_mask(cpu), ++ &sched_sg_idle_mask); ++ } ++#endif ++} ++ ++static inline struct task_struct *rq_runnable_task(struct rq *rq) ++{ ++ struct task_struct *next = sched_rq_first_task(rq); ++ ++ if (unlikely(next == rq->skip)) ++ next = sched_rq_next_task(next, rq); ++ ++ return next; ++} ++ ++/* ++ * Serialization rules: ++ * ++ * Lock order: ++ * ++ * p->pi_lock ++ * rq->lock ++ * hrtimer_cpu_base->lock (hrtimer_start() for bandwidth controls) ++ * ++ * rq1->lock ++ * rq2->lock where: rq1 < rq2 ++ * ++ * Regular state: ++ * ++ * Normal scheduling state is serialized by rq->lock. __schedule() takes the ++ * local CPU's rq->lock, it optionally removes the task from the runqueue and ++ * always looks at the local rq data structures to find the most eligible task ++ * to run next. ++ * ++ * Task enqueue is also under rq->lock, possibly taken from another CPU. ++ * Wakeups from another LLC domain might use an IPI to transfer the enqueue to ++ * the local CPU to avoid bouncing the runqueue state around [ see ++ * ttwu_queue_wakelist() ] ++ * ++ * Task wakeup, specifically wakeups that involve migration, are horribly ++ * complicated to avoid having to take two rq->locks. ++ * ++ * Special state: ++ * ++ * System-calls and anything external will use task_rq_lock() which acquires ++ * both p->pi_lock and rq->lock. As a consequence the state they change is ++ * stable while holding either lock: ++ * ++ * - sched_setaffinity()/ ++ * set_cpus_allowed_ptr(): p->cpus_ptr, p->nr_cpus_allowed ++ * - set_user_nice(): p->se.load, p->*prio ++ * - __sched_setscheduler(): p->sched_class, p->policy, p->*prio, ++ * p->se.load, p->rt_priority, ++ * p->dl.dl_{runtime, deadline, period, flags, bw, density} ++ * - sched_setnuma(): p->numa_preferred_nid ++ * - sched_move_task()/ ++ * cpu_cgroup_fork(): p->sched_task_group ++ * - uclamp_update_active() p->uclamp* ++ * ++ * p->state <- TASK_*: ++ * ++ * is changed locklessly using set_current_state(), __set_current_state() or ++ * set_special_state(), see their respective comments, or by ++ * try_to_wake_up(). This latter uses p->pi_lock to serialize against ++ * concurrent self. ++ * ++ * p->on_rq <- { 0, 1 = TASK_ON_RQ_QUEUED, 2 = TASK_ON_RQ_MIGRATING }: ++ * ++ * is set by activate_task() and cleared by deactivate_task(), under ++ * rq->lock. Non-zero indicates the task is runnable, the special ++ * ON_RQ_MIGRATING state is used for migration without holding both ++ * rq->locks. It indicates task_cpu() is not stable, see task_rq_lock(). ++ * ++ * p->on_cpu <- { 0, 1 }: ++ * ++ * is set by prepare_task() and cleared by finish_task() such that it will be ++ * set before p is scheduled-in and cleared after p is scheduled-out, both ++ * under rq->lock. Non-zero indicates the task is running on its CPU. ++ * ++ * [ The astute reader will observe that it is possible for two tasks on one ++ * CPU to have ->on_cpu = 1 at the same time. ] ++ * ++ * task_cpu(p): is changed by set_task_cpu(), the rules are: ++ * ++ * - Don't call set_task_cpu() on a blocked task: ++ * ++ * We don't care what CPU we're not running on, this simplifies hotplug, ++ * the CPU assignment of blocked tasks isn't required to be valid. ++ * ++ * - for try_to_wake_up(), called under p->pi_lock: ++ * ++ * This allows try_to_wake_up() to only take one rq->lock, see its comment. ++ * ++ * - for migration called under rq->lock: ++ * [ see task_on_rq_migrating() in task_rq_lock() ] ++ * ++ * o move_queued_task() ++ * o detach_task() ++ * ++ * - for migration called under double_rq_lock(): ++ * ++ * o __migrate_swap_task() ++ * o push_rt_task() / pull_rt_task() ++ * o push_dl_task() / pull_dl_task() ++ * o dl_task_offline_migration() ++ * ++ */ ++ ++/* ++ * Context: p->pi_lock ++ */ ++static inline struct rq ++*__task_access_lock(struct task_struct *p, raw_spinlock_t **plock) ++{ ++ struct rq *rq; ++ for (;;) { ++ rq = task_rq(p); ++ if (p->on_cpu || task_on_rq_queued(p)) { ++ raw_spin_lock(&rq->lock); ++ if (likely((p->on_cpu || task_on_rq_queued(p)) ++ && rq == task_rq(p))) { ++ *plock = &rq->lock; ++ return rq; ++ } ++ raw_spin_unlock(&rq->lock); ++ } else if (task_on_rq_migrating(p)) { ++ do { ++ cpu_relax(); ++ } while (unlikely(task_on_rq_migrating(p))); ++ } else { ++ *plock = NULL; ++ return rq; ++ } ++ } ++} ++ ++static inline void ++__task_access_unlock(struct task_struct *p, raw_spinlock_t *lock) ++{ ++ if (NULL != lock) ++ raw_spin_unlock(lock); ++} ++ ++static inline struct rq ++*task_access_lock_irqsave(struct task_struct *p, raw_spinlock_t **plock, ++ unsigned long *flags) ++{ ++ struct rq *rq; ++ for (;;) { ++ rq = task_rq(p); ++ if (p->on_cpu || task_on_rq_queued(p)) { ++ raw_spin_lock_irqsave(&rq->lock, *flags); ++ if (likely((p->on_cpu || task_on_rq_queued(p)) ++ && rq == task_rq(p))) { ++ *plock = &rq->lock; ++ return rq; ++ } ++ raw_spin_unlock_irqrestore(&rq->lock, *flags); ++ } else if (task_on_rq_migrating(p)) { ++ do { ++ cpu_relax(); ++ } while (unlikely(task_on_rq_migrating(p))); ++ } else { ++ raw_spin_lock_irqsave(&p->pi_lock, *flags); ++ if (likely(!p->on_cpu && !p->on_rq && ++ rq == task_rq(p))) { ++ *plock = &p->pi_lock; ++ return rq; ++ } ++ raw_spin_unlock_irqrestore(&p->pi_lock, *flags); ++ } ++ } ++} ++ ++static inline void ++task_access_unlock_irqrestore(struct task_struct *p, raw_spinlock_t *lock, ++ unsigned long *flags) ++{ ++ raw_spin_unlock_irqrestore(lock, *flags); ++} ++ ++/* ++ * __task_rq_lock - lock the rq @p resides on. ++ */ ++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ struct rq *rq; ++ ++ lockdep_assert_held(&p->pi_lock); ++ ++ for (;;) { ++ rq = task_rq(p); ++ raw_spin_lock(&rq->lock); ++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) ++ return rq; ++ raw_spin_unlock(&rq->lock); ++ ++ while (unlikely(task_on_rq_migrating(p))) ++ cpu_relax(); ++ } ++} ++ ++/* ++ * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. ++ */ ++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(p->pi_lock) ++ __acquires(rq->lock) ++{ ++ struct rq *rq; ++ ++ for (;;) { ++ raw_spin_lock_irqsave(&p->pi_lock, rf->flags); ++ rq = task_rq(p); ++ raw_spin_lock(&rq->lock); ++ /* ++ * move_queued_task() task_rq_lock() ++ * ++ * ACQUIRE (rq->lock) ++ * [S] ->on_rq = MIGRATING [L] rq = task_rq() ++ * WMB (__set_task_cpu()) ACQUIRE (rq->lock); ++ * [S] ->cpu = new_cpu [L] task_rq() ++ * [L] ->on_rq ++ * RELEASE (rq->lock) ++ * ++ * If we observe the old CPU in task_rq_lock(), the acquire of ++ * the old rq->lock will fully serialize against the stores. ++ * ++ * If we observe the new CPU in task_rq_lock(), the address ++ * dependency headed by '[L] rq = task_rq()' and the acquire ++ * will pair with the WMB to ensure we then also see migrating. ++ */ ++ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { ++ return rq; ++ } ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); ++ ++ while (unlikely(task_on_rq_migrating(p))) ++ cpu_relax(); ++ } ++} ++ ++static inline void ++rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ raw_spin_lock_irqsave(&rq->lock, rf->flags); ++} ++ ++static inline void ++rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock_irqrestore(&rq->lock, rf->flags); ++} ++ ++/* ++ * RQ-clock updating methods: ++ */ ++ ++static void update_rq_clock_task(struct rq *rq, s64 delta) ++{ ++/* ++ * In theory, the compile should just see 0 here, and optimize out the call ++ * to sched_rt_avg_update. But I don't trust it... ++ */ ++ s64 __maybe_unused steal = 0, irq_delta = 0; ++ ++#ifdef CONFIG_IRQ_TIME_ACCOUNTING ++ irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; ++ ++ /* ++ * Since irq_time is only updated on {soft,}irq_exit, we might run into ++ * this case when a previous update_rq_clock() happened inside a ++ * {soft,}irq region. ++ * ++ * When this happens, we stop ->clock_task and only update the ++ * prev_irq_time stamp to account for the part that fit, so that a next ++ * update will consume the rest. This ensures ->clock_task is ++ * monotonic. ++ * ++ * It does however cause some slight miss-attribution of {soft,}irq ++ * time, a more accurate solution would be to update the irq_time using ++ * the current rq->clock timestamp, except that would require using ++ * atomic ops. ++ */ ++ if (irq_delta > delta) ++ irq_delta = delta; ++ ++ rq->prev_irq_time += irq_delta; ++ delta -= irq_delta; ++#endif ++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING ++ if (static_key_false((¶virt_steal_rq_enabled))) { ++ steal = paravirt_steal_clock(cpu_of(rq)); ++ steal -= rq->prev_steal_time_rq; ++ ++ if (unlikely(steal > delta)) ++ steal = delta; ++ ++ rq->prev_steal_time_rq += steal; ++ delta -= steal; ++ } ++#endif ++ ++ rq->clock_task += delta; ++ ++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ ++ if ((irq_delta + steal)) ++ update_irq_load_avg(rq, irq_delta + steal); ++#endif ++} ++ ++static inline void update_rq_clock(struct rq *rq) ++{ ++ s64 delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; ++ ++ if (unlikely(delta <= 0)) ++ return; ++ rq->clock += delta; ++ update_rq_clock_task(rq, delta); ++} ++ ++#ifdef CONFIG_NO_HZ_FULL ++/* ++ * Tick may be needed by tasks in the runqueue depending on their policy and ++ * requirements. If tick is needed, lets send the target an IPI to kick it out ++ * of nohz mode if necessary. ++ */ ++static inline void sched_update_tick_dependency(struct rq *rq) ++{ ++ int cpu = cpu_of(rq); ++ ++ if (!tick_nohz_full_cpu(cpu)) ++ return; ++ ++ if (rq->nr_running < 2) ++ tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); ++ else ++ tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); ++} ++#else /* !CONFIG_NO_HZ_FULL */ ++static inline void sched_update_tick_dependency(struct rq *rq) { } ++#endif ++ ++/* ++ * Add/Remove/Requeue task to/from the runqueue routines ++ * Context: rq->lock ++ */ ++static inline void dequeue_task(struct task_struct *p, struct rq *rq, int flags) ++{ ++ lockdep_assert_held(&rq->lock); ++ ++ /*printk(KERN_INFO "sched: dequeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ ++ WARN_ONCE(task_rq(p) != rq, "sched: dequeue task reside on cpu%d from cpu%d\n", ++ task_cpu(p), cpu_of(rq)); ++ ++ __SCHED_DEQUEUE_TASK(p, rq, flags, update_sched_rq_watermark(rq)); ++ --rq->nr_running; ++#ifdef CONFIG_SMP ++ if (1 == rq->nr_running) ++ cpumask_clear_cpu(cpu_of(rq), &sched_rq_pending_mask); ++#endif ++ ++ sched_update_tick_dependency(rq); ++} ++ ++static inline void enqueue_task(struct task_struct *p, struct rq *rq, int flags) ++{ ++ lockdep_assert_held(&rq->lock); ++ ++ /*printk(KERN_INFO "sched: enqueue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ ++ WARN_ONCE(task_rq(p) != rq, "sched: enqueue task reside on cpu%d to cpu%d\n", ++ task_cpu(p), cpu_of(rq)); ++ ++ __SCHED_ENQUEUE_TASK(p, rq, flags); ++ update_sched_rq_watermark(rq); ++ ++rq->nr_running; ++#ifdef CONFIG_SMP ++ if (2 == rq->nr_running) ++ cpumask_set_cpu(cpu_of(rq), &sched_rq_pending_mask); ++#endif ++ ++ sched_update_tick_dependency(rq); ++} ++ ++static inline void requeue_task(struct task_struct *p, struct rq *rq) ++{ ++ lockdep_assert_held(&rq->lock); ++ /*printk(KERN_INFO "sched: requeue(%d) %px %016llx\n", cpu_of(rq), p, p->priodl);*/ ++ WARN_ONCE(task_rq(p) != rq, "sched: cpu[%d] requeue task reside on cpu%d\n", ++ cpu_of(rq), task_cpu(p)); ++ ++ __SCHED_REQUEUE_TASK(p, rq, update_sched_rq_watermark(rq)); ++} ++ ++/* ++ * cmpxchg based fetch_or, macro so it works for different integer types ++ */ ++#define fetch_or(ptr, mask) \ ++ ({ \ ++ typeof(ptr) _ptr = (ptr); \ ++ typeof(mask) _mask = (mask); \ ++ typeof(*_ptr) _old, _val = *_ptr; \ ++ \ ++ for (;;) { \ ++ _old = cmpxchg(_ptr, _val, _val | _mask); \ ++ if (_old == _val) \ ++ break; \ ++ _val = _old; \ ++ } \ ++ _old; \ ++}) ++ ++#if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) ++/* ++ * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, ++ * this avoids any races wrt polling state changes and thereby avoids ++ * spurious IPIs. ++ */ ++static bool set_nr_and_not_polling(struct task_struct *p) ++{ ++ struct thread_info *ti = task_thread_info(p); ++ return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); ++} ++ ++/* ++ * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. ++ * ++ * If this returns true, then the idle task promises to call ++ * sched_ttwu_pending() and reschedule soon. ++ */ ++static bool set_nr_if_polling(struct task_struct *p) ++{ ++ struct thread_info *ti = task_thread_info(p); ++ typeof(ti->flags) old, val = READ_ONCE(ti->flags); ++ ++ for (;;) { ++ if (!(val & _TIF_POLLING_NRFLAG)) ++ return false; ++ if (val & _TIF_NEED_RESCHED) ++ return true; ++ old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED); ++ if (old == val) ++ break; ++ val = old; ++ } ++ return true; ++} ++ ++#else ++static bool set_nr_and_not_polling(struct task_struct *p) ++{ ++ set_tsk_need_resched(p); ++ return true; ++} ++ ++#ifdef CONFIG_SMP ++static bool set_nr_if_polling(struct task_struct *p) ++{ ++ return false; ++} ++#endif ++#endif ++ ++static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task) ++{ ++ struct wake_q_node *node = &task->wake_q; ++ ++ /* ++ * Atomically grab the task, if ->wake_q is !nil already it means ++ * it's already queued (either by us or someone else) and will get the ++ * wakeup due to that. ++ * ++ * In order to ensure that a pending wakeup will observe our pending ++ * state, even in the failed case, an explicit smp_mb() must be used. ++ */ ++ smp_mb__before_atomic(); ++ if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL))) ++ return false; ++ ++ /* ++ * The head is context local, there can be no concurrency. ++ */ ++ *head->lastp = node; ++ head->lastp = &node->next; ++ return true; ++} ++ ++/** ++ * wake_q_add() - queue a wakeup for 'later' waking. ++ * @head: the wake_q_head to add @task to ++ * @task: the task to queue for 'later' wakeup ++ * ++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the ++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come ++ * instantly. ++ * ++ * This function must be used as-if it were wake_up_process(); IOW the task ++ * must be ready to be woken at this location. ++ */ ++void wake_q_add(struct wake_q_head *head, struct task_struct *task) ++{ ++ if (__wake_q_add(head, task)) ++ get_task_struct(task); ++} ++ ++/** ++ * wake_q_add_safe() - safely queue a wakeup for 'later' waking. ++ * @head: the wake_q_head to add @task to ++ * @task: the task to queue for 'later' wakeup ++ * ++ * Queue a task for later wakeup, most likely by the wake_up_q() call in the ++ * same context, _HOWEVER_ this is not guaranteed, the wakeup can come ++ * instantly. ++ * ++ * This function must be used as-if it were wake_up_process(); IOW the task ++ * must be ready to be woken at this location. ++ * ++ * This function is essentially a task-safe equivalent to wake_q_add(). Callers ++ * that already hold reference to @task can call the 'safe' version and trust ++ * wake_q to do the right thing depending whether or not the @task is already ++ * queued for wakeup. ++ */ ++void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task) ++{ ++ if (!__wake_q_add(head, task)) ++ put_task_struct(task); ++} ++ ++void wake_up_q(struct wake_q_head *head) ++{ ++ struct wake_q_node *node = head->first; ++ ++ while (node != WAKE_Q_TAIL) { ++ struct task_struct *task; ++ ++ task = container_of(node, struct task_struct, wake_q); ++ BUG_ON(!task); ++ /* task can safely be re-inserted now: */ ++ node = node->next; ++ task->wake_q.next = NULL; ++ ++ /* ++ * wake_up_process() executes a full barrier, which pairs with ++ * the queueing in wake_q_add() so as not to miss wakeups. ++ */ ++ wake_up_process(task); ++ put_task_struct(task); ++ } ++} ++ ++/* ++ * resched_curr - mark rq's current task 'to be rescheduled now'. ++ * ++ * On UP this means the setting of the need_resched flag, on SMP it ++ * might also involve a cross-CPU call to trigger the scheduler on ++ * the target CPU. ++ */ ++void resched_curr(struct rq *rq) ++{ ++ struct task_struct *curr = rq->curr; ++ int cpu; ++ ++ lockdep_assert_held(&rq->lock); ++ ++ if (test_tsk_need_resched(curr)) ++ return; ++ ++ cpu = cpu_of(rq); ++ if (cpu == smp_processor_id()) { ++ set_tsk_need_resched(curr); ++ set_preempt_need_resched(); ++ return; ++ } ++ ++ if (set_nr_and_not_polling(curr)) ++ smp_send_reschedule(cpu); ++ else ++ trace_sched_wake_idle_without_ipi(cpu); ++} ++ ++void resched_cpu(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ if (cpu_online(cpu) || cpu == smp_processor_id()) ++ resched_curr(cpu_rq(cpu)); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++} ++ ++#ifdef CONFIG_SMP ++#ifdef CONFIG_NO_HZ_COMMON ++void nohz_balance_enter_idle(int cpu) {} ++ ++void select_nohz_load_balancer(int stop_tick) {} ++ ++void set_cpu_sd_state_idle(void) {} ++ ++/* ++ * In the semi idle case, use the nearest busy CPU for migrating timers ++ * from an idle CPU. This is good for power-savings. ++ * ++ * We don't do similar optimization for completely idle system, as ++ * selecting an idle CPU will add more delays to the timers than intended ++ * (as that CPU's timer base may not be uptodate wrt jiffies etc). ++ */ ++int get_nohz_timer_target(void) ++{ ++ int i, cpu = smp_processor_id(), default_cpu = -1; ++ struct cpumask *mask; ++ ++ if (housekeeping_cpu(cpu, HK_FLAG_TIMER)) { ++ if (!idle_cpu(cpu)) ++ return cpu; ++ default_cpu = cpu; ++ } ++ ++ for (mask = per_cpu(sched_cpu_affinity_masks, cpu) + 1; ++ mask < per_cpu(sched_cpu_affinity_end_mask, cpu); mask++) ++ for_each_cpu_and(i, mask, housekeeping_cpumask(HK_FLAG_TIMER)) ++ if (!idle_cpu(i)) ++ return i; ++ ++ if (default_cpu == -1) ++ default_cpu = housekeeping_any_cpu(HK_FLAG_TIMER); ++ cpu = default_cpu; ++ ++ return cpu; ++} ++ ++/* ++ * When add_timer_on() enqueues a timer into the timer wheel of an ++ * idle CPU then this timer might expire before the next timer event ++ * which is scheduled to wake up that CPU. In case of a completely ++ * idle system the next event might even be infinite time into the ++ * future. wake_up_idle_cpu() ensures that the CPU is woken up and ++ * leaves the inner idle loop so the newly added timer is taken into ++ * account when the CPU goes back to idle and evaluates the timer ++ * wheel for the next timer event. ++ */ ++static inline void wake_up_idle_cpu(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ if (cpu == smp_processor_id()) ++ return; ++ ++ if (set_nr_and_not_polling(rq->idle)) ++ smp_send_reschedule(cpu); ++ else ++ trace_sched_wake_idle_without_ipi(cpu); ++} ++ ++static inline bool wake_up_full_nohz_cpu(int cpu) ++{ ++ /* ++ * We just need the target to call irq_exit() and re-evaluate ++ * the next tick. The nohz full kick at least implies that. ++ * If needed we can still optimize that later with an ++ * empty IRQ. ++ */ ++ if (cpu_is_offline(cpu)) ++ return true; /* Don't try to wake offline CPUs. */ ++ if (tick_nohz_full_cpu(cpu)) { ++ if (cpu != smp_processor_id() || ++ tick_nohz_tick_stopped()) ++ tick_nohz_full_kick_cpu(cpu); ++ return true; ++ } ++ ++ return false; ++} ++ ++void wake_up_nohz_cpu(int cpu) ++{ ++ if (!wake_up_full_nohz_cpu(cpu)) ++ wake_up_idle_cpu(cpu); ++} ++ ++static void nohz_csd_func(void *info) ++{ ++ struct rq *rq = info; ++ int cpu = cpu_of(rq); ++ unsigned int flags; ++ ++ /* ++ * Release the rq::nohz_csd. ++ */ ++ flags = atomic_fetch_andnot(NOHZ_KICK_MASK, nohz_flags(cpu)); ++ WARN_ON(!(flags & NOHZ_KICK_MASK)); ++ ++ rq->idle_balance = idle_cpu(cpu); ++ if (rq->idle_balance && !need_resched()) { ++ rq->nohz_idle_balance = flags; ++ raise_softirq_irqoff(SCHED_SOFTIRQ); ++ } ++} ++ ++#endif /* CONFIG_NO_HZ_COMMON */ ++#endif /* CONFIG_SMP */ ++ ++static inline void check_preempt_curr(struct rq *rq) ++{ ++ if (sched_rq_first_task(rq) != rq->curr) ++ resched_curr(rq); ++} ++ ++#ifdef CONFIG_SCHED_HRTICK ++/* ++ * Use HR-timers to deliver accurate preemption points. ++ */ ++ ++static void hrtick_clear(struct rq *rq) ++{ ++ if (hrtimer_active(&rq->hrtick_timer)) ++ hrtimer_cancel(&rq->hrtick_timer); ++} ++ ++/* ++ * High-resolution timer tick. ++ * Runs from hardirq context with interrupts disabled. ++ */ ++static enum hrtimer_restart hrtick(struct hrtimer *timer) ++{ ++ struct rq *rq = container_of(timer, struct rq, hrtick_timer); ++ struct task_struct *p; ++ ++ WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); ++ ++ raw_spin_lock(&rq->lock); ++ p = rq->curr; ++ p->time_slice = 0; ++ resched_curr(rq); ++ raw_spin_unlock(&rq->lock); ++ ++ return HRTIMER_NORESTART; ++} ++ ++/* ++ * Use hrtick when: ++ * - enabled by features ++ * - hrtimer is actually high res ++ */ ++static inline int hrtick_enabled(struct rq *rq) ++{ ++ /** ++ * Alt schedule FW doesn't support sched_feat yet ++ if (!sched_feat(HRTICK)) ++ return 0; ++ */ ++ if (!cpu_active(cpu_of(rq))) ++ return 0; ++ return hrtimer_is_hres_active(&rq->hrtick_timer); ++} ++ ++#ifdef CONFIG_SMP ++ ++static void __hrtick_restart(struct rq *rq) ++{ ++ struct hrtimer *timer = &rq->hrtick_timer; ++ ktime_t time = rq->hrtick_time; ++ ++ hrtimer_start(timer, time, HRTIMER_MODE_ABS_PINNED_HARD); ++} ++ ++/* ++ * called from hardirq (IPI) context ++ */ ++static void __hrtick_start(void *arg) ++{ ++ struct rq *rq = arg; ++ ++ raw_spin_lock(&rq->lock); ++ __hrtick_restart(rq); ++ raw_spin_unlock(&rq->lock); ++} ++ ++/* ++ * Called to set the hrtick timer state. ++ * ++ * called with rq->lock held and irqs disabled ++ */ ++void hrtick_start(struct rq *rq, u64 delay) ++{ ++ struct hrtimer *timer = &rq->hrtick_timer; ++ s64 delta; ++ ++ /* ++ * Don't schedule slices shorter than 10000ns, that just ++ * doesn't make sense and can cause timer DoS. ++ */ ++ delta = max_t(s64, delay, 10000LL); ++ ++ rq->hrtick_time = ktime_add_ns(timer->base->get_time(), delta); ++ ++ if (rq == this_rq()) ++ __hrtick_restart(rq); ++ else ++ smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd); ++} ++ ++#else ++/* ++ * Called to set the hrtick timer state. ++ * ++ * called with rq->lock held and irqs disabled ++ */ ++void hrtick_start(struct rq *rq, u64 delay) ++{ ++ /* ++ * Don't schedule slices shorter than 10000ns, that just ++ * doesn't make sense. Rely on vruntime for fairness. ++ */ ++ delay = max_t(u64, delay, 10000LL); ++ hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), ++ HRTIMER_MODE_REL_PINNED_HARD); ++} ++#endif /* CONFIG_SMP */ ++ ++static void hrtick_rq_init(struct rq *rq) ++{ ++#ifdef CONFIG_SMP ++ INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq); ++#endif ++ ++ hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); ++ rq->hrtick_timer.function = hrtick; ++} ++#else /* CONFIG_SCHED_HRTICK */ ++static inline int hrtick_enabled(struct rq *rq) ++{ ++ return 0; ++} ++ ++static inline void hrtick_clear(struct rq *rq) ++{ ++} ++ ++static inline void hrtick_rq_init(struct rq *rq) ++{ ++} ++#endif /* CONFIG_SCHED_HRTICK */ ++ ++/* ++ * Calculate the current priority, i.e. the priority ++ * taken into account by the scheduler. This value might ++ * be boosted by RT tasks as it will be RT if the task got ++ * RT-boosted. If not then it returns p->normal_prio. ++ */ ++static int effective_prio(struct task_struct *p) ++{ ++ p->normal_prio = normal_prio(p); ++ /* ++ * If we are RT tasks or we were boosted to RT priority, ++ * keep the priority unchanged. Otherwise, update priority ++ * to the normal priority: ++ */ ++ if (!rt_prio(p->prio)) ++ return p->normal_prio; ++ return p->prio; ++} ++ ++/* ++ * activate_task - move a task to the runqueue. ++ * ++ * Context: rq->lock ++ */ ++static void activate_task(struct task_struct *p, struct rq *rq) ++{ ++ enqueue_task(p, rq, ENQUEUE_WAKEUP); ++ p->on_rq = TASK_ON_RQ_QUEUED; ++ ++ /* ++ * If in_iowait is set, the code below may not trigger any cpufreq ++ * utilization updates, so do it here explicitly with the IOWAIT flag ++ * passed. ++ */ ++ cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT * p->in_iowait); ++} ++ ++/* ++ * deactivate_task - remove a task from the runqueue. ++ * ++ * Context: rq->lock ++ */ ++static inline void deactivate_task(struct task_struct *p, struct rq *rq) ++{ ++ dequeue_task(p, rq, DEQUEUE_SLEEP); ++ p->on_rq = 0; ++ cpufreq_update_util(rq, 0); ++} ++ ++static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) ++{ ++#ifdef CONFIG_SMP ++ /* ++ * After ->cpu is set up to a new value, task_access_lock(p, ...) can be ++ * successfully executed on another CPU. We must ensure that updates of ++ * per-task data have been completed by this moment. ++ */ ++ smp_wmb(); ++ ++#ifdef CONFIG_THREAD_INFO_IN_TASK ++ WRITE_ONCE(p->cpu, cpu); ++#else ++ WRITE_ONCE(task_thread_info(p)->cpu, cpu); ++#endif ++#endif ++} ++ ++static inline bool is_migration_disabled(struct task_struct *p) ++{ ++#ifdef CONFIG_SMP ++ return p->migration_disabled; ++#else ++ return false; ++#endif ++} ++ ++#define SCA_CHECK 0x01 ++ ++#ifdef CONFIG_SMP ++ ++void set_task_cpu(struct task_struct *p, unsigned int new_cpu) ++{ ++#ifdef CONFIG_SCHED_DEBUG ++ /* ++ * We should never call set_task_cpu() on a blocked task, ++ * ttwu() will sort out the placement. ++ */ ++ WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && ++ !p->on_rq); ++#ifdef CONFIG_LOCKDEP ++ /* ++ * The caller should hold either p->pi_lock or rq->lock, when changing ++ * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. ++ * ++ * sched_move_task() holds both and thus holding either pins the cgroup, ++ * see task_group(). ++ */ ++ WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || ++ lockdep_is_held(&task_rq(p)->lock))); ++#endif ++ /* ++ * Clearly, migrating tasks to offline CPUs is a fairly daft thing. ++ */ ++ WARN_ON_ONCE(!cpu_online(new_cpu)); ++ ++ WARN_ON_ONCE(is_migration_disabled(p)); ++#endif ++ if (task_cpu(p) == new_cpu) ++ return; ++ trace_sched_migrate_task(p, new_cpu); ++ rseq_migrate(p); ++ perf_event_task_migrate(p); ++ ++ __set_task_cpu(p, new_cpu); ++} ++ ++#define MDF_FORCE_ENABLED 0x80 ++ ++static void ++__do_set_cpus_ptr(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ /* ++ * This here violates the locking rules for affinity, since we're only ++ * supposed to change these variables while holding both rq->lock and ++ * p->pi_lock. ++ * ++ * HOWEVER, it magically works, because ttwu() is the only code that ++ * accesses these variables under p->pi_lock and only does so after ++ * smp_cond_load_acquire(&p->on_cpu, !VAL), and we're in __schedule() ++ * before finish_task(). ++ * ++ * XXX do further audits, this smells like something putrid. ++ */ ++ SCHED_WARN_ON(!p->on_cpu); ++ p->cpus_ptr = new_mask; ++} ++ ++void migrate_disable(void) ++{ ++ struct task_struct *p = current; ++ int cpu; ++ ++ if (p->migration_disabled) { ++ p->migration_disabled++; ++ return; ++ } ++ ++ preempt_disable(); ++ cpu = smp_processor_id(); ++ if (cpumask_test_cpu(cpu, &p->cpus_mask)) { ++ cpu_rq(cpu)->nr_pinned++; ++ p->migration_disabled = 1; ++ p->migration_flags &= ~MDF_FORCE_ENABLED; ++ ++ /* ++ * Violates locking rules! see comment in __do_set_cpus_ptr(). ++ */ ++ if (p->cpus_ptr == &p->cpus_mask) ++ __do_set_cpus_ptr(p, cpumask_of(cpu)); ++ } ++ preempt_enable(); ++} ++EXPORT_SYMBOL_GPL(migrate_disable); ++ ++void migrate_enable(void) ++{ ++ struct task_struct *p = current; ++ ++ if (0 == p->migration_disabled) ++ return; ++ ++ if (p->migration_disabled > 1) { ++ p->migration_disabled--; ++ return; ++ } ++ ++ /* ++ * Ensure stop_task runs either before or after this, and that ++ * __set_cpus_allowed_ptr(SCA_MIGRATE_ENABLE) doesn't schedule(). ++ */ ++ preempt_disable(); ++ /* ++ * Assumption: current should be running on allowed cpu ++ */ ++ WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &p->cpus_mask)); ++ if (p->cpus_ptr != &p->cpus_mask) ++ __do_set_cpus_ptr(p, &p->cpus_mask); ++ /* ++ * Mustn't clear migration_disabled() until cpus_ptr points back at the ++ * regular cpus_mask, otherwise things that race (eg. ++ * select_fallback_rq) get confused. ++ */ ++ barrier(); ++ p->migration_disabled = 0; ++ this_rq()->nr_pinned--; ++ preempt_enable(); ++} ++EXPORT_SYMBOL_GPL(migrate_enable); ++ ++static inline bool rq_has_pinned_tasks(struct rq *rq) ++{ ++ return rq->nr_pinned; ++} ++ ++/* ++ * Per-CPU kthreads are allowed to run on !active && online CPUs, see ++ * __set_cpus_allowed_ptr() and select_fallback_rq(). ++ */ ++static inline bool is_cpu_allowed(struct task_struct *p, int cpu) ++{ ++ /* When not in the task's cpumask, no point in looking further. */ ++ if (!cpumask_test_cpu(cpu, p->cpus_ptr)) ++ return false; ++ ++ /* migrate_disabled() must be allowed to finish. */ ++ if (is_migration_disabled(p)) ++ return cpu_online(cpu); ++ ++ /* Non kernel threads are not allowed during either online or offline. */ ++ if (!(p->flags & PF_KTHREAD)) ++ return cpu_active(cpu); ++ ++ /* KTHREAD_IS_PER_CPU is always allowed. */ ++ if (kthread_is_per_cpu(p)) ++ return cpu_online(cpu); ++ ++ /* Regular kernel threads don't get to stay during offline. */ ++ if (cpu_rq(cpu)->balance_push) ++ return false; ++ ++ /* But are allowed during online. */ ++ return cpu_online(cpu); ++} ++ ++/* ++ * This is how migration works: ++ * ++ * 1) we invoke migration_cpu_stop() on the target CPU using ++ * stop_one_cpu(). ++ * 2) stopper starts to run (implicitly forcing the migrated thread ++ * off the CPU) ++ * 3) it checks whether the migrated task is still in the wrong runqueue. ++ * 4) if it's in the wrong runqueue then the migration thread removes ++ * it and puts it into the right queue. ++ * 5) stopper completes and stop_one_cpu() returns and the migration ++ * is done. ++ */ ++ ++/* ++ * move_queued_task - move a queued task to new rq. ++ * ++ * Returns (locked) new rq. Old rq's lock is released. ++ */ ++static struct rq *move_queued_task(struct rq *rq, struct task_struct *p, int ++ new_cpu) ++{ ++ lockdep_assert_held(&rq->lock); ++ ++ WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING); ++ dequeue_task(p, rq, 0); ++ set_task_cpu(p, new_cpu); ++ raw_spin_unlock(&rq->lock); ++ ++ rq = cpu_rq(new_cpu); ++ ++ raw_spin_lock(&rq->lock); ++ BUG_ON(task_cpu(p) != new_cpu); ++ enqueue_task(p, rq, 0); ++ p->on_rq = TASK_ON_RQ_QUEUED; ++ check_preempt_curr(rq); ++ ++ return rq; ++} ++ ++struct migration_arg { ++ struct task_struct *task; ++ int dest_cpu; ++}; ++ ++/* ++ * Move (not current) task off this CPU, onto the destination CPU. We're doing ++ * this because either it can't run here any more (set_cpus_allowed() ++ * away from this CPU, or CPU going down), or because we're ++ * attempting to rebalance this task on exec (sched_exec). ++ * ++ * So we race with normal scheduler movements, but that's OK, as long ++ * as the task is no longer on this CPU. ++ */ ++static struct rq *__migrate_task(struct rq *rq, struct task_struct *p, int ++ dest_cpu) ++{ ++ /* Affinity changed (again). */ ++ if (!is_cpu_allowed(p, dest_cpu)) ++ return rq; ++ ++ update_rq_clock(rq); ++ return move_queued_task(rq, p, dest_cpu); ++} ++ ++/* ++ * migration_cpu_stop - this will be executed by a highprio stopper thread ++ * and performs thread migration by bumping thread off CPU then ++ * 'pushing' onto another runqueue. ++ */ ++static int migration_cpu_stop(void *data) ++{ ++ struct migration_arg *arg = data; ++ struct task_struct *p = arg->task; ++ struct rq *rq = this_rq(); ++ ++ /* ++ * The original target CPU might have gone down and we might ++ * be on another CPU but it doesn't matter. ++ */ ++ local_irq_disable(); ++ /* ++ * We need to explicitly wake pending tasks before running ++ * __migrate_task() such that we will not miss enforcing cpus_ptr ++ * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test. ++ */ ++ flush_smp_call_function_from_idle(); ++ ++ raw_spin_lock(&p->pi_lock); ++ raw_spin_lock(&rq->lock); ++ /* ++ * If task_rq(p) != rq, it cannot be migrated here, because we're ++ * holding rq->lock, if p->on_rq == 0 it cannot get enqueued because ++ * we're holding p->pi_lock. ++ */ ++ if (task_rq(p) == rq && task_on_rq_queued(p)) ++ rq = __migrate_task(rq, p, arg->dest_cpu); ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock(&p->pi_lock); ++ ++ local_irq_enable(); ++ return 0; ++} ++ ++static inline void ++set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ cpumask_copy(&p->cpus_mask, new_mask); ++ p->nr_cpus_allowed = cpumask_weight(new_mask); ++} ++ ++static void ++__do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ lockdep_assert_held(&p->pi_lock); ++ set_cpus_allowed_common(p, new_mask); ++} ++ ++void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ __do_set_cpus_allowed(p, new_mask); ++} ++ ++#endif ++ ++/** ++ * task_curr - is this task currently executing on a CPU? ++ * @p: the task in question. ++ * ++ * Return: 1 if the task is currently executing. 0 otherwise. ++ */ ++inline int task_curr(const struct task_struct *p) ++{ ++ return cpu_curr(task_cpu(p)) == p; ++} ++ ++#ifdef CONFIG_SMP ++/* ++ * wait_task_inactive - wait for a thread to unschedule. ++ * ++ * If @match_state is nonzero, it's the @p->state value just checked and ++ * not expected to change. If it changes, i.e. @p might have woken up, ++ * then return zero. When we succeed in waiting for @p to be off its CPU, ++ * we return a positive number (its total switch count). If a second call ++ * a short while later returns the same number, the caller can be sure that ++ * @p has remained unscheduled the whole time. ++ * ++ * The caller must ensure that the task *will* unschedule sometime soon, ++ * else this function might spin for a *long* time. This function can't ++ * be called with interrupts off, or it may introduce deadlock with ++ * smp_call_function() if an IPI is sent by the same process we are ++ * waiting to become inactive. ++ */ ++unsigned long wait_task_inactive(struct task_struct *p, long match_state) ++{ ++ unsigned long flags; ++ bool running, on_rq; ++ unsigned long ncsw; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ ++ for (;;) { ++ rq = task_rq(p); ++ ++ /* ++ * If the task is actively running on another CPU ++ * still, just relax and busy-wait without holding ++ * any locks. ++ * ++ * NOTE! Since we don't hold any locks, it's not ++ * even sure that "rq" stays as the right runqueue! ++ * But we don't care, since this will return false ++ * if the runqueue has changed and p is actually now ++ * running somewhere else! ++ */ ++ while (task_running(p) && p == rq->curr) { ++ if (match_state && unlikely(p->state != match_state)) ++ return 0; ++ cpu_relax(); ++ } ++ ++ /* ++ * Ok, time to look more closely! We need the rq ++ * lock now, to be *sure*. If we're wrong, we'll ++ * just go back and repeat. ++ */ ++ task_access_lock_irqsave(p, &lock, &flags); ++ trace_sched_wait_task(p); ++ running = task_running(p); ++ on_rq = p->on_rq; ++ ncsw = 0; ++ if (!match_state || p->state == match_state) ++ ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ ++ task_access_unlock_irqrestore(p, lock, &flags); ++ ++ /* ++ * If it changed from the expected state, bail out now. ++ */ ++ if (unlikely(!ncsw)) ++ break; ++ ++ /* ++ * Was it really running after all now that we ++ * checked with the proper locks actually held? ++ * ++ * Oops. Go back and try again.. ++ */ ++ if (unlikely(running)) { ++ cpu_relax(); ++ continue; ++ } ++ ++ /* ++ * It's not enough that it's not actively running, ++ * it must be off the runqueue _entirely_, and not ++ * preempted! ++ * ++ * So if it was still runnable (but just not actively ++ * running right now), it's preempted, and we should ++ * yield - it could be a while. ++ */ ++ if (unlikely(on_rq)) { ++ ktime_t to = NSEC_PER_SEC / HZ; ++ ++ set_current_state(TASK_UNINTERRUPTIBLE); ++ schedule_hrtimeout(&to, HRTIMER_MODE_REL); ++ continue; ++ } ++ ++ /* ++ * Ahh, all good. It wasn't running, and it wasn't ++ * runnable, which means that it will never become ++ * running in the future either. We're all done! ++ */ ++ break; ++ } ++ ++ return ncsw; ++} ++ ++/*** ++ * kick_process - kick a running thread to enter/exit the kernel ++ * @p: the to-be-kicked thread ++ * ++ * Cause a process which is running on another CPU to enter ++ * kernel-mode, without any delay. (to get signals handled.) ++ * ++ * NOTE: this function doesn't have to take the runqueue lock, ++ * because all it wants to ensure is that the remote task enters ++ * the kernel. If the IPI races and the task has been migrated ++ * to another CPU then no harm is done and the purpose has been ++ * achieved as well. ++ */ ++void kick_process(struct task_struct *p) ++{ ++ int cpu; ++ ++ preempt_disable(); ++ cpu = task_cpu(p); ++ if ((cpu != smp_processor_id()) && task_curr(p)) ++ smp_send_reschedule(cpu); ++ preempt_enable(); ++} ++EXPORT_SYMBOL_GPL(kick_process); ++ ++/* ++ * ->cpus_ptr is protected by both rq->lock and p->pi_lock ++ * ++ * A few notes on cpu_active vs cpu_online: ++ * ++ * - cpu_active must be a subset of cpu_online ++ * ++ * - on CPU-up we allow per-CPU kthreads on the online && !active CPU, ++ * see __set_cpus_allowed_ptr(). At this point the newly online ++ * CPU isn't yet part of the sched domains, and balancing will not ++ * see it. ++ * ++ * - on cpu-down we clear cpu_active() to mask the sched domains and ++ * avoid the load balancer to place new tasks on the to be removed ++ * CPU. Existing tasks will remain running there and will be taken ++ * off. ++ * ++ * This means that fallback selection must not select !active CPUs. ++ * And can assume that any active CPU must be online. Conversely ++ * select_task_rq() below may allow selection of !active CPUs in order ++ * to satisfy the above rules. ++ */ ++static int select_fallback_rq(int cpu, struct task_struct *p) ++{ ++ int nid = cpu_to_node(cpu); ++ const struct cpumask *nodemask = NULL; ++ enum { cpuset, possible, fail } state = cpuset; ++ int dest_cpu; ++ ++ /* ++ * If the node that the CPU is on has been offlined, cpu_to_node() ++ * will return -1. There is no CPU on the node, and we should ++ * select the CPU on the other node. ++ */ ++ if (nid != -1) { ++ nodemask = cpumask_of_node(nid); ++ ++ /* Look for allowed, online CPU in same node. */ ++ for_each_cpu(dest_cpu, nodemask) { ++ if (!cpu_active(dest_cpu)) ++ continue; ++ if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) ++ return dest_cpu; ++ } ++ } ++ ++ for (;;) { ++ /* Any allowed, online CPU? */ ++ for_each_cpu(dest_cpu, p->cpus_ptr) { ++ if (!is_cpu_allowed(p, dest_cpu)) ++ continue; ++ goto out; ++ } ++ ++ /* No more Mr. Nice Guy. */ ++ switch (state) { ++ case cpuset: ++ if (IS_ENABLED(CONFIG_CPUSETS)) { ++ cpuset_cpus_allowed_fallback(p); ++ state = possible; ++ break; ++ } ++ fallthrough; ++ case possible: ++ /* ++ * XXX When called from select_task_rq() we only ++ * hold p->pi_lock and again violate locking order. ++ * ++ * More yuck to audit. ++ */ ++ do_set_cpus_allowed(p, cpu_possible_mask); ++ state = fail; ++ break; ++ ++ case fail: ++ BUG(); ++ break; ++ } ++ } ++ ++out: ++ if (state != cpuset) { ++ /* ++ * Don't tell them about moving exiting tasks or ++ * kernel threads (both mm NULL), since they never ++ * leave kernel. ++ */ ++ if (p->mm && printk_ratelimit()) { ++ printk_deferred("process %d (%s) no longer affine to cpu%d\n", ++ task_pid_nr(p), p->comm, cpu); ++ } ++ } ++ ++ return dest_cpu; ++} ++ ++static inline int select_task_rq(struct task_struct *p, struct rq *rq) ++{ ++ cpumask_t chk_mask, tmp; ++ ++ if (unlikely(!cpumask_and(&chk_mask, p->cpus_ptr, cpu_active_mask))) ++ return select_fallback_rq(task_cpu(p), p); ++ ++ if ( ++#ifdef CONFIG_SCHED_SMT ++ cpumask_and(&tmp, &chk_mask, &sched_sg_idle_mask) || ++#endif ++ cpumask_and(&tmp, &chk_mask, &sched_rq_watermark[IDLE_WM]) || ++ cpumask_and(&tmp, &chk_mask, ++ &sched_rq_watermark[task_sched_prio(p, rq) + 1])) ++ return best_mask_cpu(task_cpu(p), &tmp); ++ ++ return best_mask_cpu(task_cpu(p), &chk_mask); ++} ++ ++void sched_set_stop_task(int cpu, struct task_struct *stop) ++{ ++ static struct lock_class_key stop_pi_lock; ++ struct sched_param stop_param = { .sched_priority = STOP_PRIO }; ++ struct sched_param start_param = { .sched_priority = 0 }; ++ struct task_struct *old_stop = cpu_rq(cpu)->stop; ++ ++ if (stop) { ++ /* ++ * Make it appear like a SCHED_FIFO task, its something ++ * userspace knows about and won't get confused about. ++ * ++ * Also, it will make PI more or less work without too ++ * much confusion -- but then, stop work should not ++ * rely on PI working anyway. ++ */ ++ sched_setscheduler_nocheck(stop, SCHED_FIFO, &stop_param); ++ ++ /* ++ * The PI code calls rt_mutex_setprio() with ->pi_lock held to ++ * adjust the effective priority of a task. As a result, ++ * rt_mutex_setprio() can trigger (RT) balancing operations, ++ * which can then trigger wakeups of the stop thread to push ++ * around the current task. ++ * ++ * The stop task itself will never be part of the PI-chain, it ++ * never blocks, therefore that ->pi_lock recursion is safe. ++ * Tell lockdep about this by placing the stop->pi_lock in its ++ * own class. ++ */ ++ lockdep_set_class(&stop->pi_lock, &stop_pi_lock); ++ } ++ ++ cpu_rq(cpu)->stop = stop; ++ ++ if (old_stop) { ++ /* ++ * Reset it back to a normal scheduling policy so that ++ * it can die in pieces. ++ */ ++ sched_setscheduler_nocheck(old_stop, SCHED_NORMAL, &start_param); ++ } ++} ++ ++/* ++ * Change a given task's CPU affinity. Migrate the thread to a ++ * proper CPU and schedule it away if the CPU it's executing on ++ * is removed from the allowed bitmask. ++ * ++ * NOTE: the caller must have a valid reference to the task, the ++ * task must not exit() & deallocate itself prematurely. The ++ * call is not atomic; no spinlocks may be held. ++ */ ++static int __set_cpus_allowed_ptr(struct task_struct *p, ++ const struct cpumask *new_mask, ++ u32 flags) ++{ ++ const struct cpumask *cpu_valid_mask = cpu_active_mask; ++ int dest_cpu; ++ unsigned long irq_flags; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ int ret = 0; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, irq_flags); ++ rq = __task_access_lock(p, &lock); ++ ++ if (p->flags & PF_KTHREAD || is_migration_disabled(p)) { ++ /* ++ * Kernel threads are allowed on online && !active CPUs, ++ * however, during cpu-hot-unplug, even these might get pushed ++ * away if not KTHREAD_IS_PER_CPU. ++ * ++ * Specifically, migration_disabled() tasks must not fail the ++ * cpumask_any_and_distribute() pick below, esp. so on ++ * SCA_MIGRATE_ENABLE, otherwise we'll not call ++ * set_cpus_allowed_common() and actually reset p->cpus_ptr. ++ */ ++ cpu_valid_mask = cpu_online_mask; ++ } ++ ++ /* ++ * Must re-check here, to close a race against __kthread_bind(), ++ * sched_setaffinity() is not guaranteed to observe the flag. ++ */ ++ if ((flags & SCA_CHECK) && (p->flags & PF_NO_SETAFFINITY)) { ++ ret = -EINVAL; ++ goto out; ++ } ++ ++ if (cpumask_equal(&p->cpus_mask, new_mask)) ++ goto out; ++ ++ dest_cpu = cpumask_any_and(cpu_valid_mask, new_mask); ++ if (dest_cpu >= nr_cpu_ids) { ++ ret = -EINVAL; ++ goto out; ++ } ++ ++ __do_set_cpus_allowed(p, new_mask); ++ ++ /* Can the task run on the task's current CPU? If so, we're done */ ++ if (cpumask_test_cpu(task_cpu(p), new_mask)) ++ goto out; ++ ++ if (p->migration_disabled) { ++ if (likely(p->cpus_ptr != &p->cpus_mask)) ++ __do_set_cpus_ptr(p, &p->cpus_mask); ++ p->migration_disabled = 0; ++ p->migration_flags |= MDF_FORCE_ENABLED; ++ /* When p is migrate_disabled, rq->lock should be held */ ++ rq->nr_pinned--; ++ } ++ ++ if (task_running(p) || p->state == TASK_WAKING) { ++ struct migration_arg arg = { p, dest_cpu }; ++ ++ /* Need help from migration thread: drop lock and wait. */ ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); ++ stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); ++ return 0; ++ } ++ if (task_on_rq_queued(p)) { ++ /* ++ * OK, since we're going to drop the lock immediately ++ * afterwards anyway. ++ */ ++ update_rq_clock(rq); ++ rq = move_queued_task(rq, p, dest_cpu); ++ lock = &rq->lock; ++ } ++ ++out: ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, irq_flags); ++ ++ return ret; ++} ++ ++int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) ++{ ++ return __set_cpus_allowed_ptr(p, new_mask, 0); ++} ++EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); ++ ++#else /* CONFIG_SMP */ ++ ++static inline int select_task_rq(struct task_struct *p, struct rq *rq) ++{ ++ return 0; ++} ++ ++static inline int ++__set_cpus_allowed_ptr(struct task_struct *p, ++ const struct cpumask *new_mask, ++ u32 flags) ++{ ++ return set_cpus_allowed_ptr(p, new_mask); ++} ++ ++static inline bool rq_has_pinned_tasks(struct rq *rq) ++{ ++ return false; ++} ++ ++#endif /* !CONFIG_SMP */ ++ ++static void ++ttwu_stat(struct task_struct *p, int cpu, int wake_flags) ++{ ++ struct rq *rq; ++ ++ if (!schedstat_enabled()) ++ return; ++ ++ rq = this_rq(); ++ ++#ifdef CONFIG_SMP ++ if (cpu == rq->cpu) ++ __schedstat_inc(rq->ttwu_local); ++ else { ++ /** Alt schedule FW ToDo: ++ * How to do ttwu_wake_remote ++ */ ++ } ++#endif /* CONFIG_SMP */ ++ ++ __schedstat_inc(rq->ttwu_count); ++} ++ ++/* ++ * Mark the task runnable and perform wakeup-preemption. ++ */ ++static inline void ++ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) ++{ ++ check_preempt_curr(rq); ++ p->state = TASK_RUNNING; ++ trace_sched_wakeup(p); ++} ++ ++static inline void ++ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) ++{ ++ if (p->sched_contributes_to_load) ++ rq->nr_uninterruptible--; ++ ++ if ( ++#ifdef CONFIG_SMP ++ !(wake_flags & WF_MIGRATED) && ++#endif ++ p->in_iowait) { ++ delayacct_blkio_end(p); ++ atomic_dec(&task_rq(p)->nr_iowait); ++ } ++ ++ activate_task(p, rq); ++ ttwu_do_wakeup(rq, p, 0); ++} ++ ++/* ++ * Consider @p being inside a wait loop: ++ * ++ * for (;;) { ++ * set_current_state(TASK_UNINTERRUPTIBLE); ++ * ++ * if (CONDITION) ++ * break; ++ * ++ * schedule(); ++ * } ++ * __set_current_state(TASK_RUNNING); ++ * ++ * between set_current_state() and schedule(). In this case @p is still ++ * runnable, so all that needs doing is change p->state back to TASK_RUNNING in ++ * an atomic manner. ++ * ++ * By taking task_rq(p)->lock we serialize against schedule(), if @p->on_rq ++ * then schedule() must still happen and p->state can be changed to ++ * TASK_RUNNING. Otherwise we lost the race, schedule() has happened, and we ++ * need to do a full wakeup with enqueue. ++ * ++ * Returns: %true when the wakeup is done, ++ * %false otherwise. ++ */ ++static int ttwu_runnable(struct task_struct *p, int wake_flags) ++{ ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ int ret = 0; ++ ++ rq = __task_access_lock(p, &lock); ++ if (task_on_rq_queued(p)) { ++ /* check_preempt_curr() may use rq clock */ ++ update_rq_clock(rq); ++ ttwu_do_wakeup(rq, p, wake_flags); ++ ret = 1; ++ } ++ __task_access_unlock(p, lock); ++ ++ return ret; ++} ++ ++#ifdef CONFIG_SMP ++void sched_ttwu_pending(void *arg) ++{ ++ struct llist_node *llist = arg; ++ struct rq *rq = this_rq(); ++ struct task_struct *p, *t; ++ struct rq_flags rf; ++ ++ if (!llist) ++ return; ++ ++ /* ++ * rq::ttwu_pending racy indication of out-standing wakeups. ++ * Races such that false-negatives are possible, since they ++ * are shorter lived that false-positives would be. ++ */ ++ WRITE_ONCE(rq->ttwu_pending, 0); ++ ++ rq_lock_irqsave(rq, &rf); ++ update_rq_clock(rq); ++ ++ llist_for_each_entry_safe(p, t, llist, wake_entry.llist) { ++ if (WARN_ON_ONCE(p->on_cpu)) ++ smp_cond_load_acquire(&p->on_cpu, !VAL); ++ ++ if (WARN_ON_ONCE(task_cpu(p) != cpu_of(rq))) ++ set_task_cpu(p, cpu_of(rq)); ++ ++ ttwu_do_activate(rq, p, p->sched_remote_wakeup ? WF_MIGRATED : 0); ++ } ++ ++ rq_unlock_irqrestore(rq, &rf); ++} ++ ++void send_call_function_single_ipi(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ if (!set_nr_if_polling(rq->idle)) ++ arch_send_call_function_single_ipi(cpu); ++ else ++ trace_sched_wake_idle_without_ipi(cpu); ++} ++ ++/* ++ * Queue a task on the target CPUs wake_list and wake the CPU via IPI if ++ * necessary. The wakee CPU on receipt of the IPI will queue the task ++ * via sched_ttwu_wakeup() for activation so the wakee incurs the cost ++ * of the wakeup instead of the waker. ++ */ ++static void __ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED); ++ ++ WRITE_ONCE(rq->ttwu_pending, 1); ++ __smp_call_single_queue(cpu, &p->wake_entry.llist); ++} ++ ++static inline bool ttwu_queue_cond(int cpu, int wake_flags) ++{ ++ /* ++ * Do not complicate things with the async wake_list while the CPU is ++ * in hotplug state. ++ */ ++ if (!cpu_active(cpu)) ++ return false; ++ ++ /* ++ * If the CPU does not share cache, then queue the task on the ++ * remote rqs wakelist to avoid accessing remote data. ++ */ ++ if (!cpus_share_cache(smp_processor_id(), cpu)) ++ return true; ++ ++ /* ++ * If the task is descheduling and the only running task on the ++ * CPU then use the wakelist to offload the task activation to ++ * the soon-to-be-idle CPU as the current CPU is likely busy. ++ * nr_running is checked to avoid unnecessary task stacking. ++ */ ++ if ((wake_flags & WF_ON_CPU) && cpu_rq(cpu)->nr_running <= 1) ++ return true; ++ ++ return false; ++} ++ ++static bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) ++{ ++ if (__is_defined(ALT_SCHED_TTWU_QUEUE) && ttwu_queue_cond(cpu, wake_flags)) { ++ if (WARN_ON_ONCE(cpu == smp_processor_id())) ++ return false; ++ ++ sched_clock_cpu(cpu); /* Sync clocks across CPUs */ ++ __ttwu_queue_wakelist(p, cpu, wake_flags); ++ return true; ++ } ++ ++ return false; ++} ++ ++void wake_up_if_idle(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ rcu_read_lock(); ++ ++ if (!is_idle_task(rcu_dereference(rq->curr))) ++ goto out; ++ ++ if (set_nr_if_polling(rq->idle)) { ++ trace_sched_wake_idle_without_ipi(cpu); ++ } else { ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ if (is_idle_task(rq->curr)) ++ smp_send_reschedule(cpu); ++ /* Else CPU is not idle, do nothing here */ ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ } ++ ++out: ++ rcu_read_unlock(); ++} ++ ++bool cpus_share_cache(int this_cpu, int that_cpu) ++{ ++ return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); ++} ++#else /* !CONFIG_SMP */ ++ ++static inline bool ttwu_queue_wakelist(struct task_struct *p, int cpu, int wake_flags) ++{ ++ return false; ++} ++ ++#endif /* CONFIG_SMP */ ++ ++static inline void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ if (ttwu_queue_wakelist(p, cpu, wake_flags)) ++ return; ++ ++ raw_spin_lock(&rq->lock); ++ update_rq_clock(rq); ++ ttwu_do_activate(rq, p, wake_flags); ++ raw_spin_unlock(&rq->lock); ++} ++ ++/* ++ * Notes on Program-Order guarantees on SMP systems. ++ * ++ * MIGRATION ++ * ++ * The basic program-order guarantee on SMP systems is that when a task [t] ++ * migrates, all its activity on its old CPU [c0] happens-before any subsequent ++ * execution on its new CPU [c1]. ++ * ++ * For migration (of runnable tasks) this is provided by the following means: ++ * ++ * A) UNLOCK of the rq(c0)->lock scheduling out task t ++ * B) migration for t is required to synchronize *both* rq(c0)->lock and ++ * rq(c1)->lock (if not at the same time, then in that order). ++ * C) LOCK of the rq(c1)->lock scheduling in task ++ * ++ * Transitivity guarantees that B happens after A and C after B. ++ * Note: we only require RCpc transitivity. ++ * Note: the CPU doing B need not be c0 or c1 ++ * ++ * Example: ++ * ++ * CPU0 CPU1 CPU2 ++ * ++ * LOCK rq(0)->lock ++ * sched-out X ++ * sched-in Y ++ * UNLOCK rq(0)->lock ++ * ++ * LOCK rq(0)->lock // orders against CPU0 ++ * dequeue X ++ * UNLOCK rq(0)->lock ++ * ++ * LOCK rq(1)->lock ++ * enqueue X ++ * UNLOCK rq(1)->lock ++ * ++ * LOCK rq(1)->lock // orders against CPU2 ++ * sched-out Z ++ * sched-in X ++ * UNLOCK rq(1)->lock ++ * ++ * ++ * BLOCKING -- aka. SLEEP + WAKEUP ++ * ++ * For blocking we (obviously) need to provide the same guarantee as for ++ * migration. However the means are completely different as there is no lock ++ * chain to provide order. Instead we do: ++ * ++ * 1) smp_store_release(X->on_cpu, 0) -- finish_task() ++ * 2) smp_cond_load_acquire(!X->on_cpu) -- try_to_wake_up() ++ * ++ * Example: ++ * ++ * CPU0 (schedule) CPU1 (try_to_wake_up) CPU2 (schedule) ++ * ++ * LOCK rq(0)->lock LOCK X->pi_lock ++ * dequeue X ++ * sched-out X ++ * smp_store_release(X->on_cpu, 0); ++ * ++ * smp_cond_load_acquire(&X->on_cpu, !VAL); ++ * X->state = WAKING ++ * set_task_cpu(X,2) ++ * ++ * LOCK rq(2)->lock ++ * enqueue X ++ * X->state = RUNNING ++ * UNLOCK rq(2)->lock ++ * ++ * LOCK rq(2)->lock // orders against CPU1 ++ * sched-out Z ++ * sched-in X ++ * UNLOCK rq(2)->lock ++ * ++ * UNLOCK X->pi_lock ++ * UNLOCK rq(0)->lock ++ * ++ * ++ * However; for wakeups there is a second guarantee we must provide, namely we ++ * must observe the state that lead to our wakeup. That is, not only must our ++ * task observe its own prior state, it must also observe the stores prior to ++ * its wakeup. ++ * ++ * This means that any means of doing remote wakeups must order the CPU doing ++ * the wakeup against the CPU the task is going to end up running on. This, ++ * however, is already required for the regular Program-Order guarantee above, ++ * since the waking CPU is the one issueing the ACQUIRE (smp_cond_load_acquire). ++ * ++ */ ++ ++/** ++ * try_to_wake_up - wake up a thread ++ * @p: the thread to be awakened ++ * @state: the mask of task states that can be woken ++ * @wake_flags: wake modifier flags (WF_*) ++ * ++ * Conceptually does: ++ * ++ * If (@state & @p->state) @p->state = TASK_RUNNING. ++ * ++ * If the task was not queued/runnable, also place it back on a runqueue. ++ * ++ * This function is atomic against schedule() which would dequeue the task. ++ * ++ * It issues a full memory barrier before accessing @p->state, see the comment ++ * with set_current_state(). ++ * ++ * Uses p->pi_lock to serialize against concurrent wake-ups. ++ * ++ * Relies on p->pi_lock stabilizing: ++ * - p->sched_class ++ * - p->cpus_ptr ++ * - p->sched_task_group ++ * in order to do migration, see its use of select_task_rq()/set_task_cpu(). ++ * ++ * Tries really hard to only take one task_rq(p)->lock for performance. ++ * Takes rq->lock in: ++ * - ttwu_runnable() -- old rq, unavoidable, see comment there; ++ * - ttwu_queue() -- new rq, for enqueue of the task; ++ * - psi_ttwu_dequeue() -- much sadness :-( accounting will kill us. ++ * ++ * As a consequence we race really badly with just about everything. See the ++ * many memory barriers and their comments for details. ++ * ++ * Return: %true if @p->state changes (an actual wakeup was done), ++ * %false otherwise. ++ */ ++static int try_to_wake_up(struct task_struct *p, unsigned int state, ++ int wake_flags) ++{ ++ unsigned long flags; ++ int cpu, success = 0; ++ ++ preempt_disable(); ++ if (p == current) { ++ /* ++ * We're waking current, this means 'p->on_rq' and 'task_cpu(p) ++ * == smp_processor_id()'. Together this means we can special ++ * case the whole 'p->on_rq && ttwu_runnable()' case below ++ * without taking any locks. ++ * ++ * In particular: ++ * - we rely on Program-Order guarantees for all the ordering, ++ * - we're serialized against set_special_state() by virtue of ++ * it disabling IRQs (this allows not taking ->pi_lock). ++ */ ++ if (!(p->state & state)) ++ goto out; ++ ++ success = 1; ++ trace_sched_waking(p); ++ p->state = TASK_RUNNING; ++ trace_sched_wakeup(p); ++ goto out; ++ } ++ ++ /* ++ * If we are going to wake up a thread waiting for CONDITION we ++ * need to ensure that CONDITION=1 done by the caller can not be ++ * reordered with p->state check below. This pairs with smp_store_mb() ++ * in set_current_state() that the waiting thread does. ++ */ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ smp_mb__after_spinlock(); ++ if (!(p->state & state)) ++ goto unlock; ++ ++ trace_sched_waking(p); ++ ++ /* We're going to change ->state: */ ++ success = 1; ++ ++ /* ++ * Ensure we load p->on_rq _after_ p->state, otherwise it would ++ * be possible to, falsely, observe p->on_rq == 0 and get stuck ++ * in smp_cond_load_acquire() below. ++ * ++ * sched_ttwu_pending() try_to_wake_up() ++ * STORE p->on_rq = 1 LOAD p->state ++ * UNLOCK rq->lock ++ * ++ * __schedule() (switch to task 'p') ++ * LOCK rq->lock smp_rmb(); ++ * smp_mb__after_spinlock(); ++ * UNLOCK rq->lock ++ * ++ * [task p] ++ * STORE p->state = UNINTERRUPTIBLE LOAD p->on_rq ++ * ++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in ++ * __schedule(). See the comment for smp_mb__after_spinlock(). ++ * ++ * A similar smb_rmb() lives in try_invoke_on_locked_down_task(). ++ */ ++ smp_rmb(); ++ if (READ_ONCE(p->on_rq) && ttwu_runnable(p, wake_flags)) ++ goto unlock; ++ ++#ifdef CONFIG_SMP ++ /* ++ * Ensure we load p->on_cpu _after_ p->on_rq, otherwise it would be ++ * possible to, falsely, observe p->on_cpu == 0. ++ * ++ * One must be running (->on_cpu == 1) in order to remove oneself ++ * from the runqueue. ++ * ++ * __schedule() (switch to task 'p') try_to_wake_up() ++ * STORE p->on_cpu = 1 LOAD p->on_rq ++ * UNLOCK rq->lock ++ * ++ * __schedule() (put 'p' to sleep) ++ * LOCK rq->lock smp_rmb(); ++ * smp_mb__after_spinlock(); ++ * STORE p->on_rq = 0 LOAD p->on_cpu ++ * ++ * Pairs with the LOCK+smp_mb__after_spinlock() on rq->lock in ++ * __schedule(). See the comment for smp_mb__after_spinlock(). ++ * ++ * Form a control-dep-acquire with p->on_rq == 0 above, to ensure ++ * schedule()'s deactivate_task() has 'happened' and p will no longer ++ * care about it's own p->state. See the comment in __schedule(). ++ */ ++ smp_acquire__after_ctrl_dep(); ++ ++ /* ++ * We're doing the wakeup (@success == 1), they did a dequeue (p->on_rq ++ * == 0), which means we need to do an enqueue, change p->state to ++ * TASK_WAKING such that we can unlock p->pi_lock before doing the ++ * enqueue, such as ttwu_queue_wakelist(). ++ */ ++ p->state = TASK_WAKING; ++ ++ /* ++ * If the owning (remote) CPU is still in the middle of schedule() with ++ * this task as prev, considering queueing p on the remote CPUs wake_list ++ * which potentially sends an IPI instead of spinning on p->on_cpu to ++ * let the waker make forward progress. This is safe because IRQs are ++ * disabled and the IPI will deliver after on_cpu is cleared. ++ * ++ * Ensure we load task_cpu(p) after p->on_cpu: ++ * ++ * set_task_cpu(p, cpu); ++ * STORE p->cpu = @cpu ++ * __schedule() (switch to task 'p') ++ * LOCK rq->lock ++ * smp_mb__after_spin_lock() smp_cond_load_acquire(&p->on_cpu) ++ * STORE p->on_cpu = 1 LOAD p->cpu ++ * ++ * to ensure we observe the correct CPU on which the task is currently ++ * scheduling. ++ */ ++ if (smp_load_acquire(&p->on_cpu) && ++ ttwu_queue_wakelist(p, task_cpu(p), wake_flags | WF_ON_CPU)) ++ goto unlock; ++ ++ /* ++ * If the owning (remote) CPU is still in the middle of schedule() with ++ * this task as prev, wait until it's done referencing the task. ++ * ++ * Pairs with the smp_store_release() in finish_task(). ++ * ++ * This ensures that tasks getting woken will be fully ordered against ++ * their previous state and preserve Program Order. ++ */ ++ smp_cond_load_acquire(&p->on_cpu, !VAL); ++ ++ sched_task_ttwu(p); ++ ++ cpu = select_task_rq(p, this_rq()); ++ ++ if (cpu != task_cpu(p)) { ++ if (p->in_iowait) { ++ delayacct_blkio_end(p); ++ atomic_dec(&task_rq(p)->nr_iowait); ++ } ++ ++ wake_flags |= WF_MIGRATED; ++ psi_ttwu_dequeue(p); ++ set_task_cpu(p, cpu); ++ } ++#else ++ cpu = task_cpu(p); ++#endif /* CONFIG_SMP */ ++ ++ ttwu_queue(p, cpu, wake_flags); ++unlock: ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++out: ++ if (success) ++ ttwu_stat(p, task_cpu(p), wake_flags); ++ preempt_enable(); ++ ++ return success; ++} ++ ++/** ++ * try_invoke_on_locked_down_task - Invoke a function on task in fixed state ++ * @p: Process for which the function is to be invoked, can be @current. ++ * @func: Function to invoke. ++ * @arg: Argument to function. ++ * ++ * If the specified task can be quickly locked into a definite state ++ * (either sleeping or on a given runqueue), arrange to keep it in that ++ * state while invoking @func(@arg). This function can use ->on_rq and ++ * task_curr() to work out what the state is, if required. Given that ++ * @func can be invoked with a runqueue lock held, it had better be quite ++ * lightweight. ++ * ++ * Returns: ++ * @false if the task slipped out from under the locks. ++ * @true if the task was locked onto a runqueue or is sleeping. ++ * However, @func can override this by returning @false. ++ */ ++bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg) ++{ ++ struct rq_flags rf; ++ bool ret = false; ++ struct rq *rq; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, rf.flags); ++ if (p->on_rq) { ++ rq = __task_rq_lock(p, &rf); ++ if (task_rq(p) == rq) ++ ret = func(p, arg); ++ __task_rq_unlock(rq, &rf); ++ } else { ++ switch (p->state) { ++ case TASK_RUNNING: ++ case TASK_WAKING: ++ break; ++ default: ++ smp_rmb(); // See smp_rmb() comment in try_to_wake_up(). ++ if (!p->on_rq) ++ ret = func(p, arg); ++ } ++ } ++ raw_spin_unlock_irqrestore(&p->pi_lock, rf.flags); ++ return ret; ++} ++ ++/** ++ * wake_up_process - Wake up a specific process ++ * @p: The process to be woken up. ++ * ++ * Attempt to wake up the nominated process and move it to the set of runnable ++ * processes. ++ * ++ * Return: 1 if the process was woken up, 0 if it was already running. ++ * ++ * This function executes a full memory barrier before accessing the task state. ++ */ ++int wake_up_process(struct task_struct *p) ++{ ++ return try_to_wake_up(p, TASK_NORMAL, 0); ++} ++EXPORT_SYMBOL(wake_up_process); ++ ++int wake_up_state(struct task_struct *p, unsigned int state) ++{ ++ return try_to_wake_up(p, state, 0); ++} ++ ++/* ++ * Perform scheduler related setup for a newly forked process p. ++ * p is forked by current. ++ * ++ * __sched_fork() is basic setup used by init_idle() too: ++ */ ++static inline void __sched_fork(unsigned long clone_flags, struct task_struct *p) ++{ ++ p->on_rq = 0; ++ p->on_cpu = 0; ++ p->utime = 0; ++ p->stime = 0; ++ p->sched_time = 0; ++ ++#ifdef CONFIG_PREEMPT_NOTIFIERS ++ INIT_HLIST_HEAD(&p->preempt_notifiers); ++#endif ++ ++#ifdef CONFIG_COMPACTION ++ p->capture_control = NULL; ++#endif ++#ifdef CONFIG_SMP ++ p->wake_entry.u_flags = CSD_TYPE_TTWU; ++#endif ++} ++ ++/* ++ * fork()/clone()-time setup: ++ */ ++int sched_fork(unsigned long clone_flags, struct task_struct *p) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ ++ __sched_fork(clone_flags, p); ++ /* ++ * We mark the process as NEW here. This guarantees that ++ * nobody will actually run it, and a signal or other external ++ * event cannot wake it up and insert it on the runqueue either. ++ */ ++ p->state = TASK_NEW; ++ ++ /* ++ * Make sure we do not leak PI boosting priority to the child. ++ */ ++ p->prio = current->normal_prio; ++ ++ /* ++ * Revert to default priority/policy on fork if requested. ++ */ ++ if (unlikely(p->sched_reset_on_fork)) { ++ if (task_has_rt_policy(p)) { ++ p->policy = SCHED_NORMAL; ++ p->static_prio = NICE_TO_PRIO(0); ++ p->rt_priority = 0; ++ } else if (PRIO_TO_NICE(p->static_prio) < 0) ++ p->static_prio = NICE_TO_PRIO(0); ++ ++ p->prio = p->normal_prio = normal_prio(p); ++ ++ /* ++ * We don't need the reset flag anymore after the fork. It has ++ * fulfilled its duty: ++ */ ++ p->sched_reset_on_fork = 0; ++ } ++ ++ /* ++ * The child is not yet in the pid-hash so no cgroup attach races, ++ * and the cgroup is pinned to this child due to cgroup_fork() ++ * is ran before sched_fork(). ++ * ++ * Silence PROVE_RCU. ++ */ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ /* ++ * Share the timeslice between parent and child, thus the ++ * total amount of pending timeslices in the system doesn't change, ++ * resulting in more scheduling fairness. ++ */ ++ rq = this_rq(); ++ raw_spin_lock(&rq->lock); ++ ++ rq->curr->time_slice /= 2; ++ p->time_slice = rq->curr->time_slice; ++#ifdef CONFIG_SCHED_HRTICK ++ hrtick_start(rq, rq->curr->time_slice); ++#endif ++ ++ if (p->time_slice < RESCHED_NS) { ++ p->time_slice = sched_timeslice_ns; ++ resched_curr(rq); ++ } ++ sched_task_fork(p, rq); ++ raw_spin_unlock(&rq->lock); ++ ++ rseq_migrate(p); ++ /* ++ * We're setting the CPU for the first time, we don't migrate, ++ * so use __set_task_cpu(). ++ */ ++ __set_task_cpu(p, cpu_of(rq)); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ ++#ifdef CONFIG_SCHED_INFO ++ if (unlikely(sched_info_on())) ++ memset(&p->sched_info, 0, sizeof(p->sched_info)); ++#endif ++ init_task_preempt_count(p); ++ ++ return 0; ++} ++ ++void sched_post_fork(struct task_struct *p) {} ++ ++#ifdef CONFIG_SCHEDSTATS ++ ++DEFINE_STATIC_KEY_FALSE(sched_schedstats); ++static bool __initdata __sched_schedstats = false; ++ ++static void set_schedstats(bool enabled) ++{ ++ if (enabled) ++ static_branch_enable(&sched_schedstats); ++ else ++ static_branch_disable(&sched_schedstats); ++} ++ ++void force_schedstat_enabled(void) ++{ ++ if (!schedstat_enabled()) { ++ pr_info("kernel profiling enabled schedstats, disable via kernel.sched_schedstats.\n"); ++ static_branch_enable(&sched_schedstats); ++ } ++} ++ ++static int __init setup_schedstats(char *str) ++{ ++ int ret = 0; ++ if (!str) ++ goto out; ++ ++ /* ++ * This code is called before jump labels have been set up, so we can't ++ * change the static branch directly just yet. Instead set a temporary ++ * variable so init_schedstats() can do it later. ++ */ ++ if (!strcmp(str, "enable")) { ++ __sched_schedstats = true; ++ ret = 1; ++ } else if (!strcmp(str, "disable")) { ++ __sched_schedstats = false; ++ ret = 1; ++ } ++out: ++ if (!ret) ++ pr_warn("Unable to parse schedstats=\n"); ++ ++ return ret; ++} ++__setup("schedstats=", setup_schedstats); ++ ++static void __init init_schedstats(void) ++{ ++ set_schedstats(__sched_schedstats); ++} ++ ++#ifdef CONFIG_PROC_SYSCTL ++int sysctl_schedstats(struct ctl_table *table, int write, ++ void __user *buffer, size_t *lenp, loff_t *ppos) ++{ ++ struct ctl_table t; ++ int err; ++ int state = static_branch_likely(&sched_schedstats); ++ ++ if (write && !capable(CAP_SYS_ADMIN)) ++ return -EPERM; ++ ++ t = *table; ++ t.data = &state; ++ err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); ++ if (err < 0) ++ return err; ++ if (write) ++ set_schedstats(state); ++ return err; ++} ++#endif /* CONFIG_PROC_SYSCTL */ ++#else /* !CONFIG_SCHEDSTATS */ ++static inline void init_schedstats(void) {} ++#endif /* CONFIG_SCHEDSTATS */ ++ ++/* ++ * wake_up_new_task - wake up a newly created task for the first time. ++ * ++ * This function will do some initial scheduler statistics housekeeping ++ * that must be done for every newly created context, then puts the task ++ * on the runqueue and wakes it. ++ */ ++void wake_up_new_task(struct task_struct *p) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ ++ p->state = TASK_RUNNING; ++ ++ rq = cpu_rq(select_task_rq(p, this_rq())); ++#ifdef CONFIG_SMP ++ rseq_migrate(p); ++ /* ++ * Fork balancing, do it here and not earlier because: ++ * - cpus_ptr can change in the fork path ++ * - any previously selected CPU might disappear through hotplug ++ * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq, ++ * as we're not fully set-up yet. ++ */ ++ __set_task_cpu(p, cpu_of(rq)); ++#endif ++ ++ raw_spin_lock(&rq->lock); ++ ++ update_rq_clock(rq); ++ activate_task(p, rq); ++ trace_sched_wakeup_new(p); ++ check_preempt_curr(rq); ++ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++} ++ ++#ifdef CONFIG_PREEMPT_NOTIFIERS ++ ++static DEFINE_STATIC_KEY_FALSE(preempt_notifier_key); ++ ++void preempt_notifier_inc(void) ++{ ++ static_branch_inc(&preempt_notifier_key); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_inc); ++ ++void preempt_notifier_dec(void) ++{ ++ static_branch_dec(&preempt_notifier_key); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_dec); ++ ++/** ++ * preempt_notifier_register - tell me when current is being preempted & rescheduled ++ * @notifier: notifier struct to register ++ */ ++void preempt_notifier_register(struct preempt_notifier *notifier) ++{ ++ if (!static_branch_unlikely(&preempt_notifier_key)) ++ WARN(1, "registering preempt_notifier while notifiers disabled\n"); ++ ++ hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_register); ++ ++/** ++ * preempt_notifier_unregister - no longer interested in preemption notifications ++ * @notifier: notifier struct to unregister ++ * ++ * This is *not* safe to call from within a preemption notifier. ++ */ ++void preempt_notifier_unregister(struct preempt_notifier *notifier) ++{ ++ hlist_del(¬ifier->link); ++} ++EXPORT_SYMBOL_GPL(preempt_notifier_unregister); ++ ++static void __fire_sched_in_preempt_notifiers(struct task_struct *curr) ++{ ++ struct preempt_notifier *notifier; ++ ++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) ++ notifier->ops->sched_in(notifier, raw_smp_processor_id()); ++} ++ ++static __always_inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) ++{ ++ if (static_branch_unlikely(&preempt_notifier_key)) ++ __fire_sched_in_preempt_notifiers(curr); ++} ++ ++static void ++__fire_sched_out_preempt_notifiers(struct task_struct *curr, ++ struct task_struct *next) ++{ ++ struct preempt_notifier *notifier; ++ ++ hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) ++ notifier->ops->sched_out(notifier, next); ++} ++ ++static __always_inline void ++fire_sched_out_preempt_notifiers(struct task_struct *curr, ++ struct task_struct *next) ++{ ++ if (static_branch_unlikely(&preempt_notifier_key)) ++ __fire_sched_out_preempt_notifiers(curr, next); ++} ++ ++#else /* !CONFIG_PREEMPT_NOTIFIERS */ ++ ++static inline void fire_sched_in_preempt_notifiers(struct task_struct *curr) ++{ ++} ++ ++static inline void ++fire_sched_out_preempt_notifiers(struct task_struct *curr, ++ struct task_struct *next) ++{ ++} ++ ++#endif /* CONFIG_PREEMPT_NOTIFIERS */ ++ ++static inline void prepare_task(struct task_struct *next) ++{ ++ /* ++ * Claim the task as running, we do this before switching to it ++ * such that any running task will have this set. ++ * ++ * See the ttwu() WF_ON_CPU case and its ordering comment. ++ */ ++ WRITE_ONCE(next->on_cpu, 1); ++} ++ ++static inline void finish_task(struct task_struct *prev) ++{ ++#ifdef CONFIG_SMP ++ /* ++ * This must be the very last reference to @prev from this CPU. After ++ * p->on_cpu is cleared, the task can be moved to a different CPU. We ++ * must ensure this doesn't happen until the switch is completely ++ * finished. ++ * ++ * In particular, the load of prev->state in finish_task_switch() must ++ * happen before this. ++ * ++ * Pairs with the smp_cond_load_acquire() in try_to_wake_up(). ++ */ ++ smp_store_release(&prev->on_cpu, 0); ++#else ++ prev->on_cpu = 0; ++#endif ++} ++ ++#ifdef CONFIG_SMP ++ ++static void do_balance_callbacks(struct rq *rq, struct callback_head *head) ++{ ++ void (*func)(struct rq *rq); ++ struct callback_head *next; ++ ++ lockdep_assert_held(&rq->lock); ++ ++ while (head) { ++ func = (void (*)(struct rq *))head->func; ++ next = head->next; ++ head->next = NULL; ++ head = next; ++ ++ func(rq); ++ } ++} ++ ++static void balance_push(struct rq *rq); ++ ++struct callback_head balance_push_callback = { ++ .next = NULL, ++ .func = (void (*)(struct callback_head *))balance_push, ++}; ++ ++static inline struct callback_head *splice_balance_callbacks(struct rq *rq) ++{ ++ struct callback_head *head = rq->balance_callback; ++ ++ if (head) { ++ lockdep_assert_held(&rq->lock); ++ rq->balance_callback = NULL; ++ } ++ ++ return head; ++} ++ ++static void __balance_callbacks(struct rq *rq) ++{ ++ do_balance_callbacks(rq, splice_balance_callbacks(rq)); ++} ++ ++static inline void balance_callbacks(struct rq *rq, struct callback_head *head) ++{ ++ unsigned long flags; ++ ++ if (unlikely(head)) { ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ do_balance_callbacks(rq, head); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ } ++} ++ ++#else ++ ++static inline void __balance_callbacks(struct rq *rq) ++{ ++} ++ ++static inline struct callback_head *splice_balance_callbacks(struct rq *rq) ++{ ++ return NULL; ++} ++ ++static inline void balance_callbacks(struct rq *rq, struct callback_head *head) ++{ ++} ++ ++#endif ++ ++static inline void ++prepare_lock_switch(struct rq *rq, struct task_struct *next) ++{ ++ /* ++ * Since the runqueue lock will be released by the next ++ * task (which is an invalid locking op but in the case ++ * of the scheduler it's an obvious special-case), so we ++ * do an early lockdep release here: ++ */ ++ spin_release(&rq->lock.dep_map, _THIS_IP_); ++#ifdef CONFIG_DEBUG_SPINLOCK ++ /* this is a valid case when another task releases the spinlock */ ++ rq->lock.owner = next; ++#endif ++} ++ ++static inline void finish_lock_switch(struct rq *rq) ++{ ++ /* ++ * If we are tracking spinlock dependencies then we have to ++ * fix up the runqueue lock - which gets 'carried over' from ++ * prev into current: ++ */ ++ spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); ++ __balance_callbacks(rq); ++ raw_spin_unlock_irq(&rq->lock); ++} ++ ++/* ++ * NOP if the arch has not defined these: ++ */ ++ ++#ifndef prepare_arch_switch ++# define prepare_arch_switch(next) do { } while (0) ++#endif ++ ++#ifndef finish_arch_post_lock_switch ++# define finish_arch_post_lock_switch() do { } while (0) ++#endif ++ ++static inline void kmap_local_sched_out(void) ++{ ++#ifdef CONFIG_KMAP_LOCAL ++ if (unlikely(current->kmap_ctrl.idx)) ++ __kmap_local_sched_out(); ++#endif ++} ++ ++static inline void kmap_local_sched_in(void) ++{ ++#ifdef CONFIG_KMAP_LOCAL ++ if (unlikely(current->kmap_ctrl.idx)) ++ __kmap_local_sched_in(); ++#endif ++} ++ ++/** ++ * prepare_task_switch - prepare to switch tasks ++ * @rq: the runqueue preparing to switch ++ * @next: the task we are going to switch to. ++ * ++ * This is called with the rq lock held and interrupts off. It must ++ * be paired with a subsequent finish_task_switch after the context ++ * switch. ++ * ++ * prepare_task_switch sets up locking and calls architecture specific ++ * hooks. ++ */ ++static inline void ++prepare_task_switch(struct rq *rq, struct task_struct *prev, ++ struct task_struct *next) ++{ ++ kcov_prepare_switch(prev); ++ sched_info_switch(rq, prev, next); ++ perf_event_task_sched_out(prev, next); ++ rseq_preempt(prev); ++ fire_sched_out_preempt_notifiers(prev, next); ++ kmap_local_sched_out(); ++ prepare_task(next); ++ prepare_arch_switch(next); ++} ++ ++/** ++ * finish_task_switch - clean up after a task-switch ++ * @rq: runqueue associated with task-switch ++ * @prev: the thread we just switched away from. ++ * ++ * finish_task_switch must be called after the context switch, paired ++ * with a prepare_task_switch call before the context switch. ++ * finish_task_switch will reconcile locking set up by prepare_task_switch, ++ * and do any other architecture-specific cleanup actions. ++ * ++ * Note that we may have delayed dropping an mm in context_switch(). If ++ * so, we finish that here outside of the runqueue lock. (Doing it ++ * with the lock held can cause deadlocks; see schedule() for ++ * details.) ++ * ++ * The context switch have flipped the stack from under us and restored the ++ * local variables which were saved when this task called schedule() in the ++ * past. prev == current is still correct but we need to recalculate this_rq ++ * because prev may have moved to another CPU. ++ */ ++static struct rq *finish_task_switch(struct task_struct *prev) ++ __releases(rq->lock) ++{ ++ struct rq *rq = this_rq(); ++ struct mm_struct *mm = rq->prev_mm; ++ long prev_state; ++ ++ /* ++ * The previous task will have left us with a preempt_count of 2 ++ * because it left us after: ++ * ++ * schedule() ++ * preempt_disable(); // 1 ++ * __schedule() ++ * raw_spin_lock_irq(&rq->lock) // 2 ++ * ++ * Also, see FORK_PREEMPT_COUNT. ++ */ ++ if (WARN_ONCE(preempt_count() != 2*PREEMPT_DISABLE_OFFSET, ++ "corrupted preempt_count: %s/%d/0x%x\n", ++ current->comm, current->pid, preempt_count())) ++ preempt_count_set(FORK_PREEMPT_COUNT); ++ ++ rq->prev_mm = NULL; ++ ++ /* ++ * A task struct has one reference for the use as "current". ++ * If a task dies, then it sets TASK_DEAD in tsk->state and calls ++ * schedule one last time. The schedule call will never return, and ++ * the scheduled task must drop that reference. ++ * ++ * We must observe prev->state before clearing prev->on_cpu (in ++ * finish_task), otherwise a concurrent wakeup can get prev ++ * running on another CPU and we could rave with its RUNNING -> DEAD ++ * transition, resulting in a double drop. ++ */ ++ prev_state = prev->state; ++ vtime_task_switch(prev); ++ perf_event_task_sched_in(prev, current); ++ finish_task(prev); ++ finish_lock_switch(rq); ++ finish_arch_post_lock_switch(); ++ kcov_finish_switch(current); ++ /* ++ * kmap_local_sched_out() is invoked with rq::lock held and ++ * interrupts disabled. There is no requirement for that, but the ++ * sched out code does not have an interrupt enabled section. ++ * Restoring the maps on sched in does not require interrupts being ++ * disabled either. ++ */ ++ kmap_local_sched_in(); ++ ++ fire_sched_in_preempt_notifiers(current); ++ /* ++ * When switching through a kernel thread, the loop in ++ * membarrier_{private,global}_expedited() may have observed that ++ * kernel thread and not issued an IPI. It is therefore possible to ++ * schedule between user->kernel->user threads without passing though ++ * switch_mm(). Membarrier requires a barrier after storing to ++ * rq->curr, before returning to userspace, so provide them here: ++ * ++ * - a full memory barrier for {PRIVATE,GLOBAL}_EXPEDITED, implicitly ++ * provided by mmdrop(), ++ * - a sync_core for SYNC_CORE. ++ */ ++ if (mm) { ++ membarrier_mm_sync_core_before_usermode(mm); ++ mmdrop(mm); ++ } ++ if (unlikely(prev_state == TASK_DEAD)) { ++ /* ++ * Remove function-return probe instances associated with this ++ * task and put them back on the free list. ++ */ ++ kprobe_flush_task(prev); ++ ++ /* Task is done with its stack. */ ++ put_task_stack(prev); ++ ++ put_task_struct_rcu_user(prev); ++ } ++ ++ tick_nohz_task_switch(); ++ return rq; ++} ++ ++/** ++ * schedule_tail - first thing a freshly forked thread must call. ++ * @prev: the thread we just switched away from. ++ */ ++asmlinkage __visible void schedule_tail(struct task_struct *prev) ++ __releases(rq->lock) ++{ ++ struct rq *rq; ++ ++ /* ++ * New tasks start with FORK_PREEMPT_COUNT, see there and ++ * finish_task_switch() for details. ++ * ++ * finish_task_switch() will drop rq->lock() and lower preempt_count ++ * and the preempt_enable() will end up enabling preemption (on ++ * PREEMPT_COUNT kernels). ++ */ ++ ++ rq = finish_task_switch(prev); ++ preempt_enable(); ++ ++ if (current->set_child_tid) ++ put_user(task_pid_vnr(current), current->set_child_tid); ++ ++ calculate_sigpending(); ++} ++ ++/* ++ * context_switch - switch to the new MM and the new thread's register state. ++ */ ++static __always_inline struct rq * ++context_switch(struct rq *rq, struct task_struct *prev, ++ struct task_struct *next) ++{ ++ prepare_task_switch(rq, prev, next); ++ ++ /* ++ * For paravirt, this is coupled with an exit in switch_to to ++ * combine the page table reload and the switch backend into ++ * one hypercall. ++ */ ++ arch_start_context_switch(prev); ++ ++ /* ++ * kernel -> kernel lazy + transfer active ++ * user -> kernel lazy + mmgrab() active ++ * ++ * kernel -> user switch + mmdrop() active ++ * user -> user switch ++ */ ++ if (!next->mm) { // to kernel ++ enter_lazy_tlb(prev->active_mm, next); ++ ++ next->active_mm = prev->active_mm; ++ if (prev->mm) // from user ++ mmgrab(prev->active_mm); ++ else ++ prev->active_mm = NULL; ++ } else { // to user ++ membarrier_switch_mm(rq, prev->active_mm, next->mm); ++ /* ++ * sys_membarrier() requires an smp_mb() between setting ++ * rq->curr / membarrier_switch_mm() and returning to userspace. ++ * ++ * The below provides this either through switch_mm(), or in ++ * case 'prev->active_mm == next->mm' through ++ * finish_task_switch()'s mmdrop(). ++ */ ++ switch_mm_irqs_off(prev->active_mm, next->mm, next); ++ ++ if (!prev->mm) { // from kernel ++ /* will mmdrop() in finish_task_switch(). */ ++ rq->prev_mm = prev->active_mm; ++ prev->active_mm = NULL; ++ } ++ } ++ ++ prepare_lock_switch(rq, next); ++ ++ /* Here we just switch the register state and the stack. */ ++ switch_to(prev, next, prev); ++ barrier(); ++ ++ return finish_task_switch(prev); ++} ++ ++/* ++ * nr_running, nr_uninterruptible and nr_context_switches: ++ * ++ * externally visible scheduler statistics: current number of runnable ++ * threads, total number of context switches performed since bootup. ++ */ ++unsigned long nr_running(void) ++{ ++ unsigned long i, sum = 0; ++ ++ for_each_online_cpu(i) ++ sum += cpu_rq(i)->nr_running; ++ ++ return sum; ++} ++ ++/* ++ * Check if only the current task is running on the CPU. ++ * ++ * Caution: this function does not check that the caller has disabled ++ * preemption, thus the result might have a time-of-check-to-time-of-use ++ * race. The caller is responsible to use it correctly, for example: ++ * ++ * - from a non-preemptible section (of course) ++ * ++ * - from a thread that is bound to a single CPU ++ * ++ * - in a loop with very short iterations (e.g. a polling loop) ++ */ ++bool single_task_running(void) ++{ ++ return raw_rq()->nr_running == 1; ++} ++EXPORT_SYMBOL(single_task_running); ++ ++unsigned long long nr_context_switches(void) ++{ ++ int i; ++ unsigned long long sum = 0; ++ ++ for_each_possible_cpu(i) ++ sum += cpu_rq(i)->nr_switches; ++ ++ return sum; ++} ++ ++/* ++ * Consumers of these two interfaces, like for example the cpuidle menu ++ * governor, are using nonsensical data. Preferring shallow idle state selection ++ * for a CPU that has IO-wait which might not even end up running the task when ++ * it does become runnable. ++ */ ++ ++unsigned long nr_iowait_cpu(int cpu) ++{ ++ return atomic_read(&cpu_rq(cpu)->nr_iowait); ++} ++ ++/* ++ * IO-wait accounting, and how it's mostly bollocks (on SMP). ++ * ++ * The idea behind IO-wait account is to account the idle time that we could ++ * have spend running if it were not for IO. That is, if we were to improve the ++ * storage performance, we'd have a proportional reduction in IO-wait time. ++ * ++ * This all works nicely on UP, where, when a task blocks on IO, we account ++ * idle time as IO-wait, because if the storage were faster, it could've been ++ * running and we'd not be idle. ++ * ++ * This has been extended to SMP, by doing the same for each CPU. This however ++ * is broken. ++ * ++ * Imagine for instance the case where two tasks block on one CPU, only the one ++ * CPU will have IO-wait accounted, while the other has regular idle. Even ++ * though, if the storage were faster, both could've ran at the same time, ++ * utilising both CPUs. ++ * ++ * This means, that when looking globally, the current IO-wait accounting on ++ * SMP is a lower bound, by reason of under accounting. ++ * ++ * Worse, since the numbers are provided per CPU, they are sometimes ++ * interpreted per CPU, and that is nonsensical. A blocked task isn't strictly ++ * associated with any one particular CPU, it can wake to another CPU than it ++ * blocked on. This means the per CPU IO-wait number is meaningless. ++ * ++ * Task CPU affinities can make all that even more 'interesting'. ++ */ ++ ++unsigned long nr_iowait(void) ++{ ++ unsigned long i, sum = 0; ++ ++ for_each_possible_cpu(i) ++ sum += nr_iowait_cpu(i); ++ ++ return sum; ++} ++ ++#ifdef CONFIG_SMP ++ ++/* ++ * sched_exec - execve() is a valuable balancing opportunity, because at ++ * this point the task has the smallest effective memory and cache ++ * footprint. ++ */ ++void sched_exec(void) ++{ ++ struct task_struct *p = current; ++ unsigned long flags; ++ int dest_cpu; ++ struct rq *rq; ++ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ rq = this_rq(); ++ ++ if (rq != task_rq(p) || rq->nr_running < 2) ++ goto unlock; ++ ++ dest_cpu = select_task_rq(p, task_rq(p)); ++ if (dest_cpu == smp_processor_id()) ++ goto unlock; ++ ++ if (likely(cpu_active(dest_cpu))) { ++ struct migration_arg arg = { p, dest_cpu }; ++ ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); ++ return; ++ } ++unlock: ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++} ++ ++#endif ++ ++DEFINE_PER_CPU(struct kernel_stat, kstat); ++DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); ++ ++EXPORT_PER_CPU_SYMBOL(kstat); ++EXPORT_PER_CPU_SYMBOL(kernel_cpustat); ++ ++static inline void update_curr(struct rq *rq, struct task_struct *p) ++{ ++ s64 ns = rq->clock_task - p->last_ran; ++ ++ p->sched_time += ns; ++ account_group_exec_runtime(p, ns); ++ ++ p->time_slice -= ns; ++ p->last_ran = rq->clock_task; ++} ++ ++/* ++ * Return accounted runtime for the task. ++ * Return separately the current's pending runtime that have not been ++ * accounted yet. ++ */ ++unsigned long long task_sched_runtime(struct task_struct *p) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ u64 ns; ++ ++#if defined(CONFIG_64BIT) && defined(CONFIG_SMP) ++ /* ++ * 64-bit doesn't need locks to atomically read a 64-bit value. ++ * So we have a optimization chance when the task's delta_exec is 0. ++ * Reading ->on_cpu is racy, but this is ok. ++ * ++ * If we race with it leaving CPU, we'll take a lock. So we're correct. ++ * If we race with it entering CPU, unaccounted time is 0. This is ++ * indistinguishable from the read occurring a few cycles earlier. ++ * If we see ->on_cpu without ->on_rq, the task is leaving, and has ++ * been accounted, so we're correct here as well. ++ */ ++ if (!p->on_cpu || !task_on_rq_queued(p)) ++ return tsk_seruntime(p); ++#endif ++ ++ rq = task_access_lock_irqsave(p, &lock, &flags); ++ /* ++ * Must be ->curr _and_ ->on_rq. If dequeued, we would ++ * project cycles that may never be accounted to this ++ * thread, breaking clock_gettime(). ++ */ ++ if (p == rq->curr && task_on_rq_queued(p)) { ++ update_rq_clock(rq); ++ update_curr(rq, p); ++ } ++ ns = tsk_seruntime(p); ++ task_access_unlock_irqrestore(p, lock, &flags); ++ ++ return ns; ++} ++ ++/* This manages tasks that have run out of timeslice during a scheduler_tick */ ++static inline void scheduler_task_tick(struct rq *rq) ++{ ++ struct task_struct *p = rq->curr; ++ ++ if (is_idle_task(p)) ++ return; ++ ++ update_curr(rq, p); ++ cpufreq_update_util(rq, 0); ++ ++ /* ++ * Tasks have less than RESCHED_NS of time slice left they will be ++ * rescheduled. ++ */ ++ if (p->time_slice >= RESCHED_NS) ++ return; ++ set_tsk_need_resched(p); ++ set_preempt_need_resched(); ++} ++ ++/* ++ * This function gets called by the timer code, with HZ frequency. ++ * We call it with interrupts disabled. ++ */ ++void scheduler_tick(void) ++{ ++ int cpu __maybe_unused = smp_processor_id(); ++ struct rq *rq = cpu_rq(cpu); ++ ++ arch_scale_freq_tick(); ++ sched_clock_tick(); ++ ++ raw_spin_lock(&rq->lock); ++ update_rq_clock(rq); ++ ++ scheduler_task_tick(rq); ++ calc_global_load_tick(rq); ++ psi_task_tick(rq); ++ ++ rq->last_tick = rq->clock; ++ raw_spin_unlock(&rq->lock); ++ ++ perf_event_task_tick(); ++} ++ ++#ifdef CONFIG_SCHED_SMT ++static inline int active_load_balance_cpu_stop(void *data) ++{ ++ struct rq *rq = this_rq(); ++ struct task_struct *p = data; ++ cpumask_t tmp; ++ unsigned long flags; ++ ++ local_irq_save(flags); ++ ++ raw_spin_lock(&p->pi_lock); ++ raw_spin_lock(&rq->lock); ++ ++ rq->active_balance = 0; ++ /* _something_ may have changed the task, double check again */ ++ if (task_on_rq_queued(p) && task_rq(p) == rq && ++ cpumask_and(&tmp, p->cpus_ptr, &sched_sg_idle_mask) && ++ !is_migration_disabled(p)) { ++ int cpu = cpu_of(rq); ++ int dcpu = __best_mask_cpu(cpu, &tmp, ++ per_cpu(sched_cpu_llc_mask, cpu)); ++ rq = move_queued_task(rq, p, dcpu); ++ } ++ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock(&p->pi_lock); ++ ++ local_irq_restore(flags); ++ ++ return 0; ++} ++ ++/* sg_balance_trigger - trigger slibing group balance for @cpu */ ++static inline int sg_balance_trigger(const int cpu) ++{ ++ struct rq *rq= cpu_rq(cpu); ++ unsigned long flags; ++ struct task_struct *curr; ++ int res; ++ ++ if (!raw_spin_trylock_irqsave(&rq->lock, flags)) ++ return 0; ++ curr = rq->curr; ++ res = (!is_idle_task(curr)) && (1 == rq->nr_running) &&\ ++ cpumask_intersects(curr->cpus_ptr, &sched_sg_idle_mask) &&\ ++ !is_migration_disabled(curr) && (!rq->active_balance); ++ ++ if (res) ++ rq->active_balance = 1; ++ ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++ if (res) ++ stop_one_cpu_nowait(cpu, active_load_balance_cpu_stop, ++ curr, &rq->active_balance_work); ++ return res; ++} ++ ++/* ++ * sg_balance_check - slibing group balance check for run queue @rq ++ */ ++static inline void sg_balance_check(struct rq *rq) ++{ ++ cpumask_t chk; ++ int cpu; ++ ++ /* exit when no sg in idle */ ++ if (cpumask_empty(&sched_sg_idle_mask)) ++ return; ++ ++ /* exit when cpu is offline */ ++ if (unlikely(!rq->online)) ++ return; ++ ++ cpu = cpu_of(rq); ++ /* ++ * Only cpu in slibing idle group will do the checking and then ++ * find potential cpus which can migrate the current running task ++ */ ++ if (cpumask_test_cpu(cpu, &sched_sg_idle_mask) && ++ cpumask_andnot(&chk, cpu_online_mask, &sched_rq_pending_mask) && ++ cpumask_andnot(&chk, &chk, &sched_rq_watermark[IDLE_WM])) { ++ int i, tried = 0; ++ ++ for_each_cpu_wrap(i, &chk, cpu) { ++ if (cpumask_subset(cpu_smt_mask(i), &chk)) { ++ if (sg_balance_trigger(i)) ++ return; ++ if (tried) ++ return; ++ tried++; ++ } ++ } ++ } ++} ++#endif /* CONFIG_SCHED_SMT */ ++ ++#ifdef CONFIG_NO_HZ_FULL ++ ++struct tick_work { ++ int cpu; ++ atomic_t state; ++ struct delayed_work work; ++}; ++/* Values for ->state, see diagram below. */ ++#define TICK_SCHED_REMOTE_OFFLINE 0 ++#define TICK_SCHED_REMOTE_OFFLINING 1 ++#define TICK_SCHED_REMOTE_RUNNING 2 ++ ++/* ++ * State diagram for ->state: ++ * ++ * ++ * TICK_SCHED_REMOTE_OFFLINE ++ * | ^ ++ * | | ++ * | | sched_tick_remote() ++ * | | ++ * | | ++ * +--TICK_SCHED_REMOTE_OFFLINING ++ * | ^ ++ * | | ++ * sched_tick_start() | | sched_tick_stop() ++ * | | ++ * V | ++ * TICK_SCHED_REMOTE_RUNNING ++ * ++ * ++ * Other transitions get WARN_ON_ONCE(), except that sched_tick_remote() ++ * and sched_tick_start() are happy to leave the state in RUNNING. ++ */ ++ ++static struct tick_work __percpu *tick_work_cpu; ++ ++static void sched_tick_remote(struct work_struct *work) ++{ ++ struct delayed_work *dwork = to_delayed_work(work); ++ struct tick_work *twork = container_of(dwork, struct tick_work, work); ++ int cpu = twork->cpu; ++ struct rq *rq = cpu_rq(cpu); ++ struct task_struct *curr; ++ unsigned long flags; ++ u64 delta; ++ int os; ++ ++ /* ++ * Handle the tick only if it appears the remote CPU is running in full ++ * dynticks mode. The check is racy by nature, but missing a tick or ++ * having one too much is no big deal because the scheduler tick updates ++ * statistics and checks timeslices in a time-independent way, regardless ++ * of when exactly it is running. ++ */ ++ if (!tick_nohz_tick_stopped_cpu(cpu)) ++ goto out_requeue; ++ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ curr = rq->curr; ++ if (cpu_is_offline(cpu)) ++ goto out_unlock; ++ ++ update_rq_clock(rq); ++ if (!is_idle_task(curr)) { ++ /* ++ * Make sure the next tick runs within a reasonable ++ * amount of time. ++ */ ++ delta = rq_clock_task(rq) - curr->last_ran; ++ WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3); ++ } ++ scheduler_task_tick(rq); ++ ++ calc_load_nohz_remote(rq); ++out_unlock: ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++out_requeue: ++ /* ++ * Run the remote tick once per second (1Hz). This arbitrary ++ * frequency is large enough to avoid overload but short enough ++ * to keep scheduler internal stats reasonably up to date. But ++ * first update state to reflect hotplug activity if required. ++ */ ++ os = atomic_fetch_add_unless(&twork->state, -1, TICK_SCHED_REMOTE_RUNNING); ++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_OFFLINE); ++ if (os == TICK_SCHED_REMOTE_RUNNING) ++ queue_delayed_work(system_unbound_wq, dwork, HZ); ++} ++ ++static void sched_tick_start(int cpu) ++{ ++ int os; ++ struct tick_work *twork; ++ ++ if (housekeeping_cpu(cpu, HK_FLAG_TICK)) ++ return; ++ ++ WARN_ON_ONCE(!tick_work_cpu); ++ ++ twork = per_cpu_ptr(tick_work_cpu, cpu); ++ os = atomic_xchg(&twork->state, TICK_SCHED_REMOTE_RUNNING); ++ WARN_ON_ONCE(os == TICK_SCHED_REMOTE_RUNNING); ++ if (os == TICK_SCHED_REMOTE_OFFLINE) { ++ twork->cpu = cpu; ++ INIT_DELAYED_WORK(&twork->work, sched_tick_remote); ++ queue_delayed_work(system_unbound_wq, &twork->work, HZ); ++ } ++} ++ ++#ifdef CONFIG_HOTPLUG_CPU ++static void sched_tick_stop(int cpu) ++{ ++ struct tick_work *twork; ++ ++ if (housekeeping_cpu(cpu, HK_FLAG_TICK)) ++ return; ++ ++ WARN_ON_ONCE(!tick_work_cpu); ++ ++ twork = per_cpu_ptr(tick_work_cpu, cpu); ++ cancel_delayed_work_sync(&twork->work); ++} ++#endif /* CONFIG_HOTPLUG_CPU */ ++ ++int __init sched_tick_offload_init(void) ++{ ++ tick_work_cpu = alloc_percpu(struct tick_work); ++ BUG_ON(!tick_work_cpu); ++ return 0; ++} ++ ++#else /* !CONFIG_NO_HZ_FULL */ ++static inline void sched_tick_start(int cpu) { } ++static inline void sched_tick_stop(int cpu) { } ++#endif ++ ++#if defined(CONFIG_PREEMPTION) && (defined(CONFIG_DEBUG_PREEMPT) || \ ++ defined(CONFIG_PREEMPT_TRACER)) ++/* ++ * If the value passed in is equal to the current preempt count ++ * then we just disabled preemption. Start timing the latency. ++ */ ++static inline void preempt_latency_start(int val) ++{ ++ if (preempt_count() == val) { ++ unsigned long ip = get_lock_parent_ip(); ++#ifdef CONFIG_DEBUG_PREEMPT ++ current->preempt_disable_ip = ip; ++#endif ++ trace_preempt_off(CALLER_ADDR0, ip); ++ } ++} ++ ++void preempt_count_add(int val) ++{ ++#ifdef CONFIG_DEBUG_PREEMPT ++ /* ++ * Underflow? ++ */ ++ if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) ++ return; ++#endif ++ __preempt_count_add(val); ++#ifdef CONFIG_DEBUG_PREEMPT ++ /* ++ * Spinlock count overflowing soon? ++ */ ++ DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= ++ PREEMPT_MASK - 10); ++#endif ++ preempt_latency_start(val); ++} ++EXPORT_SYMBOL(preempt_count_add); ++NOKPROBE_SYMBOL(preempt_count_add); ++ ++/* ++ * If the value passed in equals to the current preempt count ++ * then we just enabled preemption. Stop timing the latency. ++ */ ++static inline void preempt_latency_stop(int val) ++{ ++ if (preempt_count() == val) ++ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip()); ++} ++ ++void preempt_count_sub(int val) ++{ ++#ifdef CONFIG_DEBUG_PREEMPT ++ /* ++ * Underflow? ++ */ ++ if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) ++ return; ++ /* ++ * Is the spinlock portion underflowing? ++ */ ++ if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && ++ !(preempt_count() & PREEMPT_MASK))) ++ return; ++#endif ++ ++ preempt_latency_stop(val); ++ __preempt_count_sub(val); ++} ++EXPORT_SYMBOL(preempt_count_sub); ++NOKPROBE_SYMBOL(preempt_count_sub); ++ ++#else ++static inline void preempt_latency_start(int val) { } ++static inline void preempt_latency_stop(int val) { } ++#endif ++ ++static inline unsigned long get_preempt_disable_ip(struct task_struct *p) ++{ ++#ifdef CONFIG_DEBUG_PREEMPT ++ return p->preempt_disable_ip; ++#else ++ return 0; ++#endif ++} ++ ++/* ++ * Print scheduling while atomic bug: ++ */ ++static noinline void __schedule_bug(struct task_struct *prev) ++{ ++ /* Save this before calling printk(), since that will clobber it */ ++ unsigned long preempt_disable_ip = get_preempt_disable_ip(current); ++ ++ if (oops_in_progress) ++ return; ++ ++ printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", ++ prev->comm, prev->pid, preempt_count()); ++ ++ debug_show_held_locks(prev); ++ print_modules(); ++ if (irqs_disabled()) ++ print_irqtrace_events(prev); ++ if (IS_ENABLED(CONFIG_DEBUG_PREEMPT) ++ && in_atomic_preempt_off()) { ++ pr_err("Preemption disabled at:"); ++ print_ip_sym(KERN_ERR, preempt_disable_ip); ++ } ++ if (panic_on_warn) ++ panic("scheduling while atomic\n"); ++ ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++ ++/* ++ * Various schedule()-time debugging checks and statistics: ++ */ ++static inline void schedule_debug(struct task_struct *prev, bool preempt) ++{ ++#ifdef CONFIG_SCHED_STACK_END_CHECK ++ if (task_stack_end_corrupted(prev)) ++ panic("corrupted stack end detected inside scheduler\n"); ++ ++ if (task_scs_end_corrupted(prev)) ++ panic("corrupted shadow stack detected inside scheduler\n"); ++#endif ++ ++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP ++ if (!preempt && prev->state && prev->non_block_count) { ++ printk(KERN_ERR "BUG: scheduling in a non-blocking section: %s/%d/%i\n", ++ prev->comm, prev->pid, prev->non_block_count); ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++ } ++#endif ++ ++ if (unlikely(in_atomic_preempt_off())) { ++ __schedule_bug(prev); ++ preempt_count_set(PREEMPT_DISABLED); ++ } ++ rcu_sleep_check(); ++ SCHED_WARN_ON(ct_state() == CONTEXT_USER); ++ ++ profile_hit(SCHED_PROFILING, __builtin_return_address(0)); ++ ++ schedstat_inc(this_rq()->sched_count); ++} ++ ++/* ++ * Compile time debug macro ++ * #define ALT_SCHED_DEBUG ++ */ ++ ++#ifdef ALT_SCHED_DEBUG ++void alt_sched_debug(void) ++{ ++ printk(KERN_INFO "sched: pending: 0x%04lx, idle: 0x%04lx, sg_idle: 0x%04lx\n", ++ sched_rq_pending_mask.bits[0], ++ sched_rq_watermark[IDLE_WM].bits[0], ++ sched_sg_idle_mask.bits[0]); ++} ++#else ++inline void alt_sched_debug(void) {} ++#endif ++ ++#ifdef CONFIG_SMP ++ ++#define SCHED_RQ_NR_MIGRATION (32U) ++/* ++ * Migrate pending tasks in @rq to @dest_cpu ++ * Will try to migrate mininal of half of @rq nr_running tasks and ++ * SCHED_RQ_NR_MIGRATION to @dest_cpu ++ */ ++static inline int ++migrate_pending_tasks(struct rq *rq, struct rq *dest_rq, const int dest_cpu) ++{ ++ struct task_struct *p, *skip = rq->curr; ++ int nr_migrated = 0; ++ int nr_tries = min(rq->nr_running / 2, SCHED_RQ_NR_MIGRATION); ++ ++ while (skip != rq->idle && nr_tries && ++ (p = sched_rq_next_task(skip, rq)) != rq->idle) { ++ skip = sched_rq_next_task(p, rq); ++ if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) { ++ __SCHED_DEQUEUE_TASK(p, rq, 0, ); ++ set_task_cpu(p, dest_cpu); ++ __SCHED_ENQUEUE_TASK(p, dest_rq, 0); ++ nr_migrated++; ++ } ++ nr_tries--; ++ } ++ ++ return nr_migrated; ++} ++ ++static inline int take_other_rq_tasks(struct rq *rq, int cpu) ++{ ++ struct cpumask *affinity_mask, *end_mask; ++ ++ if (unlikely(!rq->online)) ++ return 0; ++ ++ if (cpumask_empty(&sched_rq_pending_mask)) ++ return 0; ++ ++ affinity_mask = per_cpu(sched_cpu_affinity_masks, cpu) + 1; ++ end_mask = per_cpu(sched_cpu_affinity_end_mask, cpu); ++ do { ++ int i; ++ for_each_cpu_and(i, &sched_rq_pending_mask, affinity_mask) { ++ int nr_migrated; ++ struct rq *src_rq; ++ ++ src_rq = cpu_rq(i); ++ if (!do_raw_spin_trylock(&src_rq->lock)) ++ continue; ++ spin_acquire(&src_rq->lock.dep_map, ++ SINGLE_DEPTH_NESTING, 1, _RET_IP_); ++ ++ if ((nr_migrated = migrate_pending_tasks(src_rq, rq, cpu))) { ++ src_rq->nr_running -= nr_migrated; ++ if (src_rq->nr_running < 2) ++ cpumask_clear_cpu(i, &sched_rq_pending_mask); ++ ++ rq->nr_running += nr_migrated; ++ if (rq->nr_running > 1) ++ cpumask_set_cpu(cpu, &sched_rq_pending_mask); ++ ++ update_sched_rq_watermark(rq); ++ cpufreq_update_util(rq, 0); ++ ++ spin_release(&src_rq->lock.dep_map, _RET_IP_); ++ do_raw_spin_unlock(&src_rq->lock); ++ ++ return 1; ++ } ++ ++ spin_release(&src_rq->lock.dep_map, _RET_IP_); ++ do_raw_spin_unlock(&src_rq->lock); ++ } ++ } while (++affinity_mask < end_mask); ++ ++ return 0; ++} ++#endif ++ ++/* ++ * Timeslices below RESCHED_NS are considered as good as expired as there's no ++ * point rescheduling when there's so little time left. ++ */ ++static inline void check_curr(struct task_struct *p, struct rq *rq) ++{ ++ if (unlikely(rq->idle == p)) ++ return; ++ ++ update_curr(rq, p); ++ ++ if (p->time_slice < RESCHED_NS) ++ time_slice_expired(p, rq); ++} ++ ++static inline struct task_struct * ++choose_next_task(struct rq *rq, int cpu, struct task_struct *prev) ++{ ++ struct task_struct *next; ++ ++ if (unlikely(rq->skip)) { ++ next = rq_runnable_task(rq); ++ if (next == rq->idle) { ++#ifdef CONFIG_SMP ++ if (!take_other_rq_tasks(rq, cpu)) { ++#endif ++ rq->skip = NULL; ++ schedstat_inc(rq->sched_goidle); ++ return next; ++#ifdef CONFIG_SMP ++ } ++ next = rq_runnable_task(rq); ++#endif ++ } ++ rq->skip = NULL; ++#ifdef CONFIG_HIGH_RES_TIMERS ++ hrtick_start(rq, next->time_slice); ++#endif ++ return next; ++ } ++ ++ next = sched_rq_first_task(rq); ++ if (next == rq->idle) { ++#ifdef CONFIG_SMP ++ if (!take_other_rq_tasks(rq, cpu)) { ++#endif ++ schedstat_inc(rq->sched_goidle); ++ /*printk(KERN_INFO "sched: choose_next_task(%d) idle %px\n", cpu, next);*/ ++ return next; ++#ifdef CONFIG_SMP ++ } ++ next = sched_rq_first_task(rq); ++#endif ++ } ++#ifdef CONFIG_HIGH_RES_TIMERS ++ hrtick_start(rq, next->time_slice); ++#endif ++ /*printk(KERN_INFO "sched: choose_next_task(%d) next %px\n", cpu, ++ * next);*/ ++ return next; ++} ++ ++/* ++ * schedule() is the main scheduler function. ++ * ++ * The main means of driving the scheduler and thus entering this function are: ++ * ++ * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. ++ * ++ * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return ++ * paths. For example, see arch/x86/entry_64.S. ++ * ++ * To drive preemption between tasks, the scheduler sets the flag in timer ++ * interrupt handler scheduler_tick(). ++ * ++ * 3. Wakeups don't really cause entry into schedule(). They add a ++ * task to the run-queue and that's it. ++ * ++ * Now, if the new task added to the run-queue preempts the current ++ * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets ++ * called on the nearest possible occasion: ++ * ++ * - If the kernel is preemptible (CONFIG_PREEMPTION=y): ++ * ++ * - in syscall or exception context, at the next outmost ++ * preempt_enable(). (this might be as soon as the wake_up()'s ++ * spin_unlock()!) ++ * ++ * - in IRQ context, return from interrupt-handler to ++ * preemptible context ++ * ++ * - If the kernel is not preemptible (CONFIG_PREEMPTION is not set) ++ * then at the next: ++ * ++ * - cond_resched() call ++ * - explicit schedule() call ++ * - return from syscall or exception to user-space ++ * - return from interrupt-handler to user-space ++ * ++ * WARNING: must be called with preemption disabled! ++ */ ++static void __sched notrace __schedule(bool preempt) ++{ ++ struct task_struct *prev, *next; ++ unsigned long *switch_count; ++ unsigned long prev_state; ++ struct rq *rq; ++ int cpu; ++ ++ cpu = smp_processor_id(); ++ rq = cpu_rq(cpu); ++ prev = rq->curr; ++ ++ schedule_debug(prev, preempt); ++ ++ /* by passing sched_feat(HRTICK) checking which Alt schedule FW doesn't support */ ++ hrtick_clear(rq); ++ ++ local_irq_disable(); ++ rcu_note_context_switch(preempt); ++ ++ /* ++ * Make sure that signal_pending_state()->signal_pending() below ++ * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) ++ * done by the caller to avoid the race with signal_wake_up(): ++ * ++ * __set_current_state(@state) signal_wake_up() ++ * schedule() set_tsk_thread_flag(p, TIF_SIGPENDING) ++ * wake_up_state(p, state) ++ * LOCK rq->lock LOCK p->pi_state ++ * smp_mb__after_spinlock() smp_mb__after_spinlock() ++ * if (signal_pending_state()) if (p->state & @state) ++ * ++ * Also, the membarrier system call requires a full memory barrier ++ * after coming from user-space, before storing to rq->curr. ++ */ ++ raw_spin_lock(&rq->lock); ++ smp_mb__after_spinlock(); ++ ++ update_rq_clock(rq); ++ ++ switch_count = &prev->nivcsw; ++ /* ++ * We must load prev->state once (task_struct::state is volatile), such ++ * that: ++ * ++ * - we form a control dependency vs deactivate_task() below. ++ * - ptrace_{,un}freeze_traced() can change ->state underneath us. ++ */ ++ prev_state = prev->state; ++ if (!preempt && prev_state && prev_state == prev->state) { ++ if (signal_pending_state(prev_state, prev)) { ++ prev->state = TASK_RUNNING; ++ } else { ++ prev->sched_contributes_to_load = ++ (prev_state & TASK_UNINTERRUPTIBLE) && ++ !(prev_state & TASK_NOLOAD) && ++ !(prev->flags & PF_FROZEN); ++ ++ if (prev->sched_contributes_to_load) ++ rq->nr_uninterruptible++; ++ ++ /* ++ * __schedule() ttwu() ++ * prev_state = prev->state; if (p->on_rq && ...) ++ * if (prev_state) goto out; ++ * p->on_rq = 0; smp_acquire__after_ctrl_dep(); ++ * p->state = TASK_WAKING ++ * ++ * Where __schedule() and ttwu() have matching control dependencies. ++ * ++ * After this, schedule() must not care about p->state any more. ++ */ ++ sched_task_deactivate(prev, rq); ++ deactivate_task(prev, rq); ++ ++ if (prev->in_iowait) { ++ atomic_inc(&rq->nr_iowait); ++ delayacct_blkio_start(); ++ } ++ } ++ switch_count = &prev->nvcsw; ++ } ++ ++ check_curr(prev, rq); ++ ++ next = choose_next_task(rq, cpu, prev); ++ clear_tsk_need_resched(prev); ++ clear_preempt_need_resched(); ++ ++ ++ if (likely(prev != next)) { ++ next->last_ran = rq->clock_task; ++ rq->last_ts_switch = rq->clock; ++ ++ rq->nr_switches++; ++ /* ++ * RCU users of rcu_dereference(rq->curr) may not see ++ * changes to task_struct made by pick_next_task(). ++ */ ++ RCU_INIT_POINTER(rq->curr, next); ++ /* ++ * The membarrier system call requires each architecture ++ * to have a full memory barrier after updating ++ * rq->curr, before returning to user-space. ++ * ++ * Here are the schemes providing that barrier on the ++ * various architectures: ++ * - mm ? switch_mm() : mmdrop() for x86, s390, sparc, PowerPC. ++ * switch_mm() rely on membarrier_arch_switch_mm() on PowerPC. ++ * - finish_lock_switch() for weakly-ordered ++ * architectures where spin_unlock is a full barrier, ++ * - switch_to() for arm64 (weakly-ordered, spin_unlock ++ * is a RELEASE barrier), ++ */ ++ ++*switch_count; ++ ++ psi_sched_switch(prev, next, !task_on_rq_queued(prev)); ++ ++ trace_sched_switch(preempt, prev, next); ++ ++ /* Also unlocks the rq: */ ++ rq = context_switch(rq, prev, next); ++ } else { ++ __balance_callbacks(rq); ++ raw_spin_unlock_irq(&rq->lock); ++ } ++ ++#ifdef CONFIG_SCHED_SMT ++ sg_balance_check(rq); ++#endif ++} ++ ++void __noreturn do_task_dead(void) ++{ ++ /* Causes final put_task_struct in finish_task_switch(): */ ++ set_special_state(TASK_DEAD); ++ ++ /* Tell freezer to ignore us: */ ++ current->flags |= PF_NOFREEZE; ++ ++ __schedule(false); ++ BUG(); ++ ++ /* Avoid "noreturn function does return" - but don't continue if BUG() is a NOP: */ ++ for (;;) ++ cpu_relax(); ++} ++ ++static inline void sched_submit_work(struct task_struct *tsk) ++{ ++ unsigned int task_flags; ++ ++ if (!tsk->state) ++ return; ++ ++ task_flags = tsk->flags; ++ /* ++ * If a worker went to sleep, notify and ask workqueue whether ++ * it wants to wake up a task to maintain concurrency. ++ * As this function is called inside the schedule() context, ++ * we disable preemption to avoid it calling schedule() again ++ * in the possible wakeup of a kworker and because wq_worker_sleeping() ++ * requires it. ++ */ ++ if (task_flags & (PF_WQ_WORKER | PF_IO_WORKER)) { ++ preempt_disable(); ++ if (task_flags & PF_WQ_WORKER) ++ wq_worker_sleeping(tsk); ++ else ++ io_wq_worker_sleeping(tsk); ++ preempt_enable_no_resched(); ++ } ++ ++ if (tsk_is_pi_blocked(tsk)) ++ return; ++ ++ /* ++ * If we are going to sleep and we have plugged IO queued, ++ * make sure to submit it to avoid deadlocks. ++ */ ++ if (blk_needs_flush_plug(tsk)) ++ blk_schedule_flush_plug(tsk); ++} ++ ++static void sched_update_worker(struct task_struct *tsk) ++{ ++ if (tsk->flags & (PF_WQ_WORKER | PF_IO_WORKER)) { ++ if (tsk->flags & PF_WQ_WORKER) ++ wq_worker_running(tsk); ++ else ++ io_wq_worker_running(tsk); ++ } ++} ++ ++asmlinkage __visible void __sched schedule(void) ++{ ++ struct task_struct *tsk = current; ++ ++ sched_submit_work(tsk); ++ do { ++ preempt_disable(); ++ __schedule(false); ++ sched_preempt_enable_no_resched(); ++ } while (need_resched()); ++ sched_update_worker(tsk); ++} ++EXPORT_SYMBOL(schedule); ++ ++/* ++ * synchronize_rcu_tasks() makes sure that no task is stuck in preempted ++ * state (have scheduled out non-voluntarily) by making sure that all ++ * tasks have either left the run queue or have gone into user space. ++ * As idle tasks do not do either, they must not ever be preempted ++ * (schedule out non-voluntarily). ++ * ++ * schedule_idle() is similar to schedule_preempt_disable() except that it ++ * never enables preemption because it does not call sched_submit_work(). ++ */ ++void __sched schedule_idle(void) ++{ ++ /* ++ * As this skips calling sched_submit_work(), which the idle task does ++ * regardless because that function is a nop when the task is in a ++ * TASK_RUNNING state, make sure this isn't used someplace that the ++ * current task can be in any other state. Note, idle is always in the ++ * TASK_RUNNING state. ++ */ ++ WARN_ON_ONCE(current->state); ++ do { ++ __schedule(false); ++ } while (need_resched()); ++} ++ ++#if defined(CONFIG_CONTEXT_TRACKING) && !defined(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) ++asmlinkage __visible void __sched schedule_user(void) ++{ ++ /* ++ * If we come here after a random call to set_need_resched(), ++ * or we have been woken up remotely but the IPI has not yet arrived, ++ * we haven't yet exited the RCU idle mode. Do it here manually until ++ * we find a better solution. ++ * ++ * NB: There are buggy callers of this function. Ideally we ++ * should warn if prev_state != CONTEXT_USER, but that will trigger ++ * too frequently to make sense yet. ++ */ ++ enum ctx_state prev_state = exception_enter(); ++ schedule(); ++ exception_exit(prev_state); ++} ++#endif ++ ++/** ++ * schedule_preempt_disabled - called with preemption disabled ++ * ++ * Returns with preemption disabled. Note: preempt_count must be 1 ++ */ ++void __sched schedule_preempt_disabled(void) ++{ ++ sched_preempt_enable_no_resched(); ++ schedule(); ++ preempt_disable(); ++} ++ ++static void __sched notrace preempt_schedule_common(void) ++{ ++ do { ++ /* ++ * Because the function tracer can trace preempt_count_sub() ++ * and it also uses preempt_enable/disable_notrace(), if ++ * NEED_RESCHED is set, the preempt_enable_notrace() called ++ * by the function tracer will call this function again and ++ * cause infinite recursion. ++ * ++ * Preemption must be disabled here before the function ++ * tracer can trace. Break up preempt_disable() into two ++ * calls. One to disable preemption without fear of being ++ * traced. The other to still record the preemption latency, ++ * which can also be traced by the function tracer. ++ */ ++ preempt_disable_notrace(); ++ preempt_latency_start(1); ++ __schedule(true); ++ preempt_latency_stop(1); ++ preempt_enable_no_resched_notrace(); ++ ++ /* ++ * Check again in case we missed a preemption opportunity ++ * between schedule and now. ++ */ ++ } while (need_resched()); ++} ++ ++#ifdef CONFIG_PREEMPTION ++/* ++ * This is the entry point to schedule() from in-kernel preemption ++ * off of preempt_enable. ++ */ ++asmlinkage __visible void __sched notrace preempt_schedule(void) ++{ ++ /* ++ * If there is a non-zero preempt_count or interrupts are disabled, ++ * we do not want to preempt the current task. Just return.. ++ */ ++ if (likely(!preemptible())) ++ return; ++ ++ preempt_schedule_common(); ++} ++NOKPROBE_SYMBOL(preempt_schedule); ++EXPORT_SYMBOL(preempt_schedule); ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++DEFINE_STATIC_CALL(preempt_schedule, __preempt_schedule_func); ++EXPORT_STATIC_CALL_TRAMP(preempt_schedule); ++#endif ++ ++ ++/** ++ * preempt_schedule_notrace - preempt_schedule called by tracing ++ * ++ * The tracing infrastructure uses preempt_enable_notrace to prevent ++ * recursion and tracing preempt enabling caused by the tracing ++ * infrastructure itself. But as tracing can happen in areas coming ++ * from userspace or just about to enter userspace, a preempt enable ++ * can occur before user_exit() is called. This will cause the scheduler ++ * to be called when the system is still in usermode. ++ * ++ * To prevent this, the preempt_enable_notrace will use this function ++ * instead of preempt_schedule() to exit user context if needed before ++ * calling the scheduler. ++ */ ++asmlinkage __visible void __sched notrace preempt_schedule_notrace(void) ++{ ++ enum ctx_state prev_ctx; ++ ++ if (likely(!preemptible())) ++ return; ++ ++ do { ++ /* ++ * Because the function tracer can trace preempt_count_sub() ++ * and it also uses preempt_enable/disable_notrace(), if ++ * NEED_RESCHED is set, the preempt_enable_notrace() called ++ * by the function tracer will call this function again and ++ * cause infinite recursion. ++ * ++ * Preemption must be disabled here before the function ++ * tracer can trace. Break up preempt_disable() into two ++ * calls. One to disable preemption without fear of being ++ * traced. The other to still record the preemption latency, ++ * which can also be traced by the function tracer. ++ */ ++ preempt_disable_notrace(); ++ preempt_latency_start(1); ++ /* ++ * Needs preempt disabled in case user_exit() is traced ++ * and the tracer calls preempt_enable_notrace() causing ++ * an infinite recursion. ++ */ ++ prev_ctx = exception_enter(); ++ __schedule(true); ++ exception_exit(prev_ctx); ++ ++ preempt_latency_stop(1); ++ preempt_enable_no_resched_notrace(); ++ } while (need_resched()); ++} ++EXPORT_SYMBOL_GPL(preempt_schedule_notrace); ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++DEFINE_STATIC_CALL(preempt_schedule_notrace, __preempt_schedule_notrace_func); ++EXPORT_STATIC_CALL_TRAMP(preempt_schedule_notrace); ++#endif ++ ++#endif /* CONFIG_PREEMPTION */ ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++ ++#include <linux/entry-common.h> ++ ++/* ++ * SC:cond_resched ++ * SC:might_resched ++ * SC:preempt_schedule ++ * SC:preempt_schedule_notrace ++ * SC:irqentry_exit_cond_resched ++ * ++ * ++ * NONE: ++ * cond_resched <- __cond_resched ++ * might_resched <- RET0 ++ * preempt_schedule <- NOP ++ * preempt_schedule_notrace <- NOP ++ * irqentry_exit_cond_resched <- NOP ++ * ++ * VOLUNTARY: ++ * cond_resched <- __cond_resched ++ * might_resched <- __cond_resched ++ * preempt_schedule <- NOP ++ * preempt_schedule_notrace <- NOP ++ * irqentry_exit_cond_resched <- NOP ++ * ++ * FULL: ++ * cond_resched <- RET0 ++ * might_resched <- RET0 ++ * preempt_schedule <- preempt_schedule ++ * preempt_schedule_notrace <- preempt_schedule_notrace ++ * irqentry_exit_cond_resched <- irqentry_exit_cond_resched ++ */ ++ ++enum { ++ preempt_dynamic_none = 0, ++ preempt_dynamic_voluntary, ++ preempt_dynamic_full, ++}; ++ ++static int preempt_dynamic_mode = preempt_dynamic_full; ++ ++static int sched_dynamic_mode(const char *str) ++{ ++ if (!strcmp(str, "none")) ++ return 0; ++ ++ if (!strcmp(str, "voluntary")) ++ return 1; ++ ++ if (!strcmp(str, "full")) ++ return 2; ++ ++ return -1; ++} ++ ++static void sched_dynamic_update(int mode) ++{ ++ /* ++ * Avoid {NONE,VOLUNTARY} -> FULL transitions from ever ending up in ++ * the ZERO state, which is invalid. ++ */ ++ static_call_update(cond_resched, __cond_resched); ++ static_call_update(might_resched, __cond_resched); ++ static_call_update(preempt_schedule, __preempt_schedule_func); ++ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func); ++ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched); ++ ++ switch (mode) { ++ case preempt_dynamic_none: ++ static_call_update(cond_resched, __cond_resched); ++ static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0); ++ static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL); ++ static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL); ++ static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL); ++ pr_info("Dynamic Preempt: none\n"); ++ break; ++ ++ case preempt_dynamic_voluntary: ++ static_call_update(cond_resched, __cond_resched); ++ static_call_update(might_resched, __cond_resched); ++ static_call_update(preempt_schedule, (typeof(&preempt_schedule)) NULL); ++ static_call_update(preempt_schedule_notrace, (typeof(&preempt_schedule_notrace)) NULL); ++ static_call_update(irqentry_exit_cond_resched, (typeof(&irqentry_exit_cond_resched)) NULL); ++ pr_info("Dynamic Preempt: voluntary\n"); ++ break; ++ ++ case preempt_dynamic_full: ++ static_call_update(cond_resched, (typeof(&__cond_resched)) __static_call_return0); ++ static_call_update(might_resched, (typeof(&__cond_resched)) __static_call_return0); ++ static_call_update(preempt_schedule, __preempt_schedule_func); ++ static_call_update(preempt_schedule_notrace, __preempt_schedule_notrace_func); ++ static_call_update(irqentry_exit_cond_resched, irqentry_exit_cond_resched); ++ pr_info("Dynamic Preempt: full\n"); ++ break; ++ } ++ ++ preempt_dynamic_mode = mode; ++} ++ ++static int __init setup_preempt_mode(char *str) ++{ ++ int mode = sched_dynamic_mode(str); ++ if (mode < 0) { ++ pr_warn("Dynamic Preempt: unsupported mode: %s\n", str); ++ return 1; ++ } ++ ++ sched_dynamic_update(mode); ++ return 0; ++} ++__setup("preempt=", setup_preempt_mode); ++ ++#ifdef CONFIG_SCHED_DEBUG ++ ++static ssize_t sched_dynamic_write(struct file *filp, const char __user *ubuf, ++ size_t cnt, loff_t *ppos) ++{ ++ char buf[16]; ++ int mode; ++ ++ if (cnt > 15) ++ cnt = 15; ++ ++ if (copy_from_user(&buf, ubuf, cnt)) ++ return -EFAULT; ++ ++ buf[cnt] = 0; ++ mode = sched_dynamic_mode(strstrip(buf)); ++ if (mode < 0) ++ return mode; ++ ++ sched_dynamic_update(mode); ++ ++ *ppos += cnt; ++ ++ return cnt; ++} ++ ++static int sched_dynamic_show(struct seq_file *m, void *v) ++{ ++ static const char * preempt_modes[] = { ++ "none", "voluntary", "full" ++ }; ++ int i; ++ ++ for (i = 0; i < ARRAY_SIZE(preempt_modes); i++) { ++ if (preempt_dynamic_mode == i) ++ seq_puts(m, "("); ++ seq_puts(m, preempt_modes[i]); ++ if (preempt_dynamic_mode == i) ++ seq_puts(m, ")"); ++ ++ seq_puts(m, " "); ++ } ++ ++ seq_puts(m, "\n"); ++ return 0; ++} ++ ++static int sched_dynamic_open(struct inode *inode, struct file *filp) ++{ ++ return single_open(filp, sched_dynamic_show, NULL); ++} ++ ++static const struct file_operations sched_dynamic_fops = { ++ .open = sched_dynamic_open, ++ .write = sched_dynamic_write, ++ .read = seq_read, ++ .llseek = seq_lseek, ++ .release = single_release, ++}; ++ ++static __init int sched_init_debug_dynamic(void) ++{ ++ debugfs_create_file("sched_preempt", 0644, NULL, NULL, &sched_dynamic_fops); ++ return 0; ++} ++late_initcall(sched_init_debug_dynamic); ++ ++#endif /* CONFIG_SCHED_DEBUG */ ++#endif /* CONFIG_PREEMPT_DYNAMIC */ ++ ++ ++/* ++ * This is the entry point to schedule() from kernel preemption ++ * off of irq context. ++ * Note, that this is called and return with irqs disabled. This will ++ * protect us against recursive calling from irq. ++ */ ++asmlinkage __visible void __sched preempt_schedule_irq(void) ++{ ++ enum ctx_state prev_state; ++ ++ /* Catch callers which need to be fixed */ ++ BUG_ON(preempt_count() || !irqs_disabled()); ++ ++ prev_state = exception_enter(); ++ ++ do { ++ preempt_disable(); ++ local_irq_enable(); ++ __schedule(true); ++ local_irq_disable(); ++ sched_preempt_enable_no_resched(); ++ } while (need_resched()); ++ ++ exception_exit(prev_state); ++} ++ ++int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flags, ++ void *key) ++{ ++ WARN_ON_ONCE(IS_ENABLED(CONFIG_SCHED_DEBUG) && wake_flags & ~WF_SYNC); ++ return try_to_wake_up(curr->private, mode, wake_flags); ++} ++EXPORT_SYMBOL(default_wake_function); ++ ++static inline void check_task_changed(struct rq *rq, struct task_struct *p) ++{ ++ /* Trigger resched if task sched_prio has been modified. */ ++ if (task_on_rq_queued(p) && sched_task_need_requeue(p, rq)) { ++ requeue_task(p, rq); ++ check_preempt_curr(rq); ++ } ++} ++ ++#ifdef CONFIG_RT_MUTEXES ++ ++static inline int __rt_effective_prio(struct task_struct *pi_task, int prio) ++{ ++ if (pi_task) ++ prio = min(prio, pi_task->prio); ++ ++ return prio; ++} ++ ++static inline int rt_effective_prio(struct task_struct *p, int prio) ++{ ++ struct task_struct *pi_task = rt_mutex_get_top_task(p); ++ ++ return __rt_effective_prio(pi_task, prio); ++} ++ ++/* ++ * rt_mutex_setprio - set the current priority of a task ++ * @p: task to boost ++ * @pi_task: donor task ++ * ++ * This function changes the 'effective' priority of a task. It does ++ * not touch ->normal_prio like __setscheduler(). ++ * ++ * Used by the rt_mutex code to implement priority inheritance ++ * logic. Call site only calls if the priority of the task changed. ++ */ ++void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) ++{ ++ int prio; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ ++ /* XXX used to be waiter->prio, not waiter->task->prio */ ++ prio = __rt_effective_prio(pi_task, p->normal_prio); ++ ++ /* ++ * If nothing changed; bail early. ++ */ ++ if (p->pi_top_task == pi_task && prio == p->prio) ++ return; ++ ++ rq = __task_access_lock(p, &lock); ++ /* ++ * Set under pi_lock && rq->lock, such that the value can be used under ++ * either lock. ++ * ++ * Note that there is loads of tricky to make this pointer cache work ++ * right. rt_mutex_slowunlock()+rt_mutex_postunlock() work together to ++ * ensure a task is de-boosted (pi_task is set to NULL) before the ++ * task is allowed to run again (and can exit). This ensures the pointer ++ * points to a blocked task -- which guarantees the task is present. ++ */ ++ p->pi_top_task = pi_task; ++ ++ /* ++ * For FIFO/RR we only need to set prio, if that matches we're done. ++ */ ++ if (prio == p->prio) ++ goto out_unlock; ++ ++ /* ++ * Idle task boosting is a nono in general. There is one ++ * exception, when PREEMPT_RT and NOHZ is active: ++ * ++ * The idle task calls get_next_timer_interrupt() and holds ++ * the timer wheel base->lock on the CPU and another CPU wants ++ * to access the timer (probably to cancel it). We can safely ++ * ignore the boosting request, as the idle CPU runs this code ++ * with interrupts disabled and will complete the lock ++ * protected section without being interrupted. So there is no ++ * real need to boost. ++ */ ++ if (unlikely(p == rq->idle)) { ++ WARN_ON(p != rq->curr); ++ WARN_ON(p->pi_blocked_on); ++ goto out_unlock; ++ } ++ ++ trace_sched_pi_setprio(p, pi_task); ++ p->prio = prio; ++ update_task_priodl(p); ++ ++ check_task_changed(rq, p); ++out_unlock: ++ /* Avoid rq from going away on us: */ ++ preempt_disable(); ++ ++ __balance_callbacks(rq); ++ __task_access_unlock(p, lock); ++ ++ preempt_enable(); ++} ++#else ++static inline int rt_effective_prio(struct task_struct *p, int prio) ++{ ++ return prio; ++} ++#endif ++ ++void set_user_nice(struct task_struct *p, long nice) ++{ ++ unsigned long flags; ++ struct rq *rq; ++ raw_spinlock_t *lock; ++ ++ if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE) ++ return; ++ /* ++ * We have to be careful, if called from sys_setpriority(), ++ * the task might be in the middle of scheduling on another CPU. ++ */ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ rq = __task_access_lock(p, &lock); ++ ++ p->static_prio = NICE_TO_PRIO(nice); ++ /* ++ * The RT priorities are set via sched_setscheduler(), but we still ++ * allow the 'normal' nice value to be set - but as expected ++ * it won't have any effect on scheduling until the task is ++ * not SCHED_NORMAL/SCHED_BATCH: ++ */ ++ if (task_has_rt_policy(p)) ++ goto out_unlock; ++ ++ p->prio = effective_prio(p); ++ update_task_priodl(p); ++ ++ check_task_changed(rq, p); ++out_unlock: ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++} ++EXPORT_SYMBOL(set_user_nice); ++ ++/* ++ * can_nice - check if a task can reduce its nice value ++ * @p: task ++ * @nice: nice value ++ */ ++int can_nice(const struct task_struct *p, const int nice) ++{ ++ /* Convert nice value [19,-20] to rlimit style value [1,40] */ ++ int nice_rlim = nice_to_rlimit(nice); ++ ++ return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || ++ capable(CAP_SYS_NICE)); ++} ++ ++#ifdef __ARCH_WANT_SYS_NICE ++ ++/* ++ * sys_nice - change the priority of the current process. ++ * @increment: priority increment ++ * ++ * sys_setpriority is a more generic, but much slower function that ++ * does similar things. ++ */ ++SYSCALL_DEFINE1(nice, int, increment) ++{ ++ long nice, retval; ++ ++ /* ++ * Setpriority might change our priority at the same moment. ++ * We don't have to worry. Conceptually one call occurs first ++ * and we have a single winner. ++ */ ++ ++ increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH); ++ nice = task_nice(current) + increment; ++ ++ nice = clamp_val(nice, MIN_NICE, MAX_NICE); ++ if (increment < 0 && !can_nice(current, nice)) ++ return -EPERM; ++ ++ retval = security_task_setnice(current, nice); ++ if (retval) ++ return retval; ++ ++ set_user_nice(current, nice); ++ return 0; ++} ++ ++#endif ++ ++/** ++ * idle_cpu - is a given CPU idle currently? ++ * @cpu: the processor in question. ++ * ++ * Return: 1 if the CPU is currently idle. 0 otherwise. ++ */ ++int idle_cpu(int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ if (rq->curr != rq->idle) ++ return 0; ++ ++ if (rq->nr_running) ++ return 0; ++ ++#ifdef CONFIG_SMP ++ if (rq->ttwu_pending) ++ return 0; ++#endif ++ ++ return 1; ++} ++ ++/** ++ * idle_task - return the idle task for a given CPU. ++ * @cpu: the processor in question. ++ * ++ * Return: The idle task for the cpu @cpu. ++ */ ++struct task_struct *idle_task(int cpu) ++{ ++ return cpu_rq(cpu)->idle; ++} ++ ++/** ++ * find_process_by_pid - find a process with a matching PID value. ++ * @pid: the pid in question. ++ * ++ * The task of @pid, if found. %NULL otherwise. ++ */ ++static inline struct task_struct *find_process_by_pid(pid_t pid) ++{ ++ return pid ? find_task_by_vpid(pid) : current; ++} ++ ++/* ++ * sched_setparam() passes in -1 for its policy, to let the functions ++ * it calls know not to change it. ++ */ ++#define SETPARAM_POLICY -1 ++ ++static void __setscheduler_params(struct task_struct *p, ++ const struct sched_attr *attr) ++{ ++ int policy = attr->sched_policy; ++ ++ if (policy == SETPARAM_POLICY) ++ policy = p->policy; ++ ++ p->policy = policy; ++ ++ /* ++ * allow normal nice value to be set, but will not have any ++ * effect on scheduling until the task not SCHED_NORMAL/ ++ * SCHED_BATCH ++ */ ++ p->static_prio = NICE_TO_PRIO(attr->sched_nice); ++ ++ /* ++ * __sched_setscheduler() ensures attr->sched_priority == 0 when ++ * !rt_policy. Always setting this ensures that things like ++ * getparam()/getattr() don't report silly values for !rt tasks. ++ */ ++ p->rt_priority = attr->sched_priority; ++ p->normal_prio = normal_prio(p); ++} ++ ++/* Actually do priority change: must hold rq lock. */ ++static void __setscheduler(struct rq *rq, struct task_struct *p, ++ const struct sched_attr *attr, bool keep_boost) ++{ ++ __setscheduler_params(p, attr); ++ ++ /* ++ * Keep a potential priority boosting if called from ++ * sched_setscheduler(). ++ */ ++ p->prio = normal_prio(p); ++ if (keep_boost) ++ p->prio = rt_effective_prio(p, p->prio); ++ update_task_priodl(p); ++} ++ ++/* ++ * check the target process has a UID that matches the current process's ++ */ ++static bool check_same_owner(struct task_struct *p) ++{ ++ const struct cred *cred = current_cred(), *pcred; ++ bool match; ++ ++ rcu_read_lock(); ++ pcred = __task_cred(p); ++ match = (uid_eq(cred->euid, pcred->euid) || ++ uid_eq(cred->euid, pcred->uid)); ++ rcu_read_unlock(); ++ return match; ++} ++ ++static int __sched_setscheduler(struct task_struct *p, ++ const struct sched_attr *attr, ++ bool user, bool pi) ++{ ++ const struct sched_attr dl_squash_attr = { ++ .size = sizeof(struct sched_attr), ++ .sched_policy = SCHED_FIFO, ++ .sched_nice = 0, ++ .sched_priority = 99, ++ }; ++ int newprio = MAX_RT_PRIO - 1 - attr->sched_priority; ++ int retval, oldpolicy = -1; ++ int policy = attr->sched_policy; ++ struct callback_head *head; ++ unsigned long flags; ++ struct rq *rq; ++ int reset_on_fork; ++ raw_spinlock_t *lock; ++ ++ /* The pi code expects interrupts enabled */ ++ BUG_ON(pi && in_interrupt()); ++ ++ /* ++ * Alt schedule FW supports SCHED_DEADLINE by squash it as prio 0 SCHED_FIFO ++ */ ++ if (unlikely(SCHED_DEADLINE == policy)) { ++ attr = &dl_squash_attr; ++ policy = attr->sched_policy; ++ newprio = MAX_RT_PRIO - 1 - attr->sched_priority; ++ } ++recheck: ++ /* Double check policy once rq lock held */ ++ if (policy < 0) { ++ reset_on_fork = p->sched_reset_on_fork; ++ policy = oldpolicy = p->policy; ++ } else { ++ reset_on_fork = !!(attr->sched_flags & SCHED_RESET_ON_FORK); ++ ++ if (policy > SCHED_IDLE) ++ return -EINVAL; ++ } ++ ++ if (attr->sched_flags & ~(SCHED_FLAG_ALL)) ++ return -EINVAL; ++ ++ /* ++ * Valid priorities for SCHED_FIFO and SCHED_RR are ++ * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL and ++ * SCHED_BATCH and SCHED_IDLE is 0. ++ */ ++ if (attr->sched_priority < 0 || ++ (p->mm && attr->sched_priority > MAX_RT_PRIO - 1) || ++ (!p->mm && attr->sched_priority > MAX_RT_PRIO - 1)) ++ return -EINVAL; ++ if ((SCHED_RR == policy || SCHED_FIFO == policy) != ++ (attr->sched_priority != 0)) ++ return -EINVAL; ++ ++ /* ++ * Allow unprivileged RT tasks to decrease priority: ++ */ ++ if (user && !capable(CAP_SYS_NICE)) { ++ if (SCHED_FIFO == policy || SCHED_RR == policy) { ++ unsigned long rlim_rtprio = ++ task_rlimit(p, RLIMIT_RTPRIO); ++ ++ /* Can't set/change the rt policy */ ++ if (policy != p->policy && !rlim_rtprio) ++ return -EPERM; ++ ++ /* Can't increase priority */ ++ if (attr->sched_priority > p->rt_priority && ++ attr->sched_priority > rlim_rtprio) ++ return -EPERM; ++ } ++ ++ /* Can't change other user's priorities */ ++ if (!check_same_owner(p)) ++ return -EPERM; ++ ++ /* Normal users shall not reset the sched_reset_on_fork flag */ ++ if (p->sched_reset_on_fork && !reset_on_fork) ++ return -EPERM; ++ } ++ ++ if (user) { ++ retval = security_task_setscheduler(p); ++ if (retval) ++ return retval; ++ } ++ ++ if (pi) ++ cpuset_read_lock(); ++ ++ /* ++ * Make sure no PI-waiters arrive (or leave) while we are ++ * changing the priority of the task: ++ */ ++ raw_spin_lock_irqsave(&p->pi_lock, flags); ++ ++ /* ++ * To be able to change p->policy safely, task_access_lock() ++ * must be called. ++ * IF use task_access_lock() here: ++ * For the task p which is not running, reading rq->stop is ++ * racy but acceptable as ->stop doesn't change much. ++ * An enhancemnet can be made to read rq->stop saftly. ++ */ ++ rq = __task_access_lock(p, &lock); ++ ++ /* ++ * Changing the policy of the stop threads its a very bad idea ++ */ ++ if (p == rq->stop) { ++ retval = -EINVAL; ++ goto unlock; ++ } ++ ++ /* ++ * If not changing anything there's no need to proceed further: ++ */ ++ if (unlikely(policy == p->policy)) { ++ if (rt_policy(policy) && attr->sched_priority != p->rt_priority) ++ goto change; ++ if (!rt_policy(policy) && ++ NICE_TO_PRIO(attr->sched_nice) != p->static_prio) ++ goto change; ++ ++ p->sched_reset_on_fork = reset_on_fork; ++ retval = 0; ++ goto unlock; ++ } ++change: ++ ++ /* Re-check policy now with rq lock held */ ++ if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { ++ policy = oldpolicy = -1; ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ if (pi) ++ cpuset_read_unlock(); ++ goto recheck; ++ } ++ ++ p->sched_reset_on_fork = reset_on_fork; ++ ++ if (pi) { ++ /* ++ * Take priority boosted tasks into account. If the new ++ * effective priority is unchanged, we just store the new ++ * normal parameters and do not touch the scheduler class and ++ * the runqueue. This will be done when the task deboost ++ * itself. ++ */ ++ if (rt_effective_prio(p, newprio) == p->prio) { ++ __setscheduler_params(p, attr); ++ retval = 0; ++ goto unlock; ++ } ++ } ++ ++ __setscheduler(rq, p, attr, pi); ++ ++ check_task_changed(rq, p); ++ ++ /* Avoid rq from going away on us: */ ++ preempt_disable(); ++ head = splice_balance_callbacks(rq); ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ ++ if (pi) { ++ cpuset_read_unlock(); ++ rt_mutex_adjust_pi(p); ++ } ++ ++ /* Run balance callbacks after we've adjusted the PI chain: */ ++ balance_callbacks(rq, head); ++ preempt_enable(); ++ ++ return 0; ++ ++unlock: ++ __task_access_unlock(p, lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, flags); ++ if (pi) ++ cpuset_read_unlock(); ++ return retval; ++} ++ ++static int _sched_setscheduler(struct task_struct *p, int policy, ++ const struct sched_param *param, bool check) ++{ ++ struct sched_attr attr = { ++ .sched_policy = policy, ++ .sched_priority = param->sched_priority, ++ .sched_nice = PRIO_TO_NICE(p->static_prio), ++ }; ++ ++ /* Fixup the legacy SCHED_RESET_ON_FORK hack. */ ++ if ((policy != SETPARAM_POLICY) && (policy & SCHED_RESET_ON_FORK)) { ++ attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; ++ policy &= ~SCHED_RESET_ON_FORK; ++ attr.sched_policy = policy; ++ } ++ ++ return __sched_setscheduler(p, &attr, check, true); ++} ++ ++/** ++ * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. ++ * @p: the task in question. ++ * @policy: new policy. ++ * @param: structure containing the new RT priority. ++ * ++ * Use sched_set_fifo(), read its comment. ++ * ++ * Return: 0 on success. An error code otherwise. ++ * ++ * NOTE that the task may be already dead. ++ */ ++int sched_setscheduler(struct task_struct *p, int policy, ++ const struct sched_param *param) ++{ ++ return _sched_setscheduler(p, policy, param, true); ++} ++ ++int sched_setattr(struct task_struct *p, const struct sched_attr *attr) ++{ ++ return __sched_setscheduler(p, attr, true, true); ++} ++ ++int sched_setattr_nocheck(struct task_struct *p, const struct sched_attr *attr) ++{ ++ return __sched_setscheduler(p, attr, false, true); ++} ++ ++/** ++ * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. ++ * @p: the task in question. ++ * @policy: new policy. ++ * @param: structure containing the new RT priority. ++ * ++ * Just like sched_setscheduler, only don't bother checking if the ++ * current context has permission. For example, this is needed in ++ * stop_machine(): we create temporary high priority worker threads, ++ * but our caller might not have that capability. ++ * ++ * Return: 0 on success. An error code otherwise. ++ */ ++int sched_setscheduler_nocheck(struct task_struct *p, int policy, ++ const struct sched_param *param) ++{ ++ return _sched_setscheduler(p, policy, param, false); ++} ++ ++/* ++ * SCHED_FIFO is a broken scheduler model; that is, it is fundamentally ++ * incapable of resource management, which is the one thing an OS really should ++ * be doing. ++ * ++ * This is of course the reason it is limited to privileged users only. ++ * ++ * Worse still; it is fundamentally impossible to compose static priority ++ * workloads. You cannot take two correctly working static prio workloads ++ * and smash them together and still expect them to work. ++ * ++ * For this reason 'all' FIFO tasks the kernel creates are basically at: ++ * ++ * MAX_RT_PRIO / 2 ++ * ++ * The administrator _MUST_ configure the system, the kernel simply doesn't ++ * know enough information to make a sensible choice. ++ */ ++void sched_set_fifo(struct task_struct *p) ++{ ++ struct sched_param sp = { .sched_priority = MAX_RT_PRIO / 2 }; ++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); ++} ++EXPORT_SYMBOL_GPL(sched_set_fifo); ++ ++/* ++ * For when you don't much care about FIFO, but want to be above SCHED_NORMAL. ++ */ ++void sched_set_fifo_low(struct task_struct *p) ++{ ++ struct sched_param sp = { .sched_priority = 1 }; ++ WARN_ON_ONCE(sched_setscheduler_nocheck(p, SCHED_FIFO, &sp) != 0); ++} ++EXPORT_SYMBOL_GPL(sched_set_fifo_low); ++ ++void sched_set_normal(struct task_struct *p, int nice) ++{ ++ struct sched_attr attr = { ++ .sched_policy = SCHED_NORMAL, ++ .sched_nice = nice, ++ }; ++ WARN_ON_ONCE(sched_setattr_nocheck(p, &attr) != 0); ++} ++EXPORT_SYMBOL_GPL(sched_set_normal); ++ ++static int ++do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) ++{ ++ struct sched_param lparam; ++ struct task_struct *p; ++ int retval; ++ ++ if (!param || pid < 0) ++ return -EINVAL; ++ if (copy_from_user(&lparam, param, sizeof(struct sched_param))) ++ return -EFAULT; ++ ++ rcu_read_lock(); ++ retval = -ESRCH; ++ p = find_process_by_pid(pid); ++ if (likely(p)) ++ get_task_struct(p); ++ rcu_read_unlock(); ++ ++ if (likely(p)) { ++ retval = sched_setscheduler(p, policy, &lparam); ++ put_task_struct(p); ++ } ++ ++ return retval; ++} ++ ++/* ++ * Mimics kernel/events/core.c perf_copy_attr(). ++ */ ++static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *attr) ++{ ++ u32 size; ++ int ret; ++ ++ /* Zero the full structure, so that a short copy will be nice: */ ++ memset(attr, 0, sizeof(*attr)); ++ ++ ret = get_user(size, &uattr->size); ++ if (ret) ++ return ret; ++ ++ /* ABI compatibility quirk: */ ++ if (!size) ++ size = SCHED_ATTR_SIZE_VER0; ++ ++ if (size < SCHED_ATTR_SIZE_VER0 || size > PAGE_SIZE) ++ goto err_size; ++ ++ ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size); ++ if (ret) { ++ if (ret == -E2BIG) ++ goto err_size; ++ return ret; ++ } ++ ++ /* ++ * XXX: Do we want to be lenient like existing syscalls; or do we want ++ * to be strict and return an error on out-of-bounds values? ++ */ ++ attr->sched_nice = clamp(attr->sched_nice, -20, 19); ++ ++ /* sched/core.c uses zero here but we already know ret is zero */ ++ return 0; ++ ++err_size: ++ put_user(sizeof(*attr), &uattr->size); ++ return -E2BIG; ++} ++ ++/** ++ * sys_sched_setscheduler - set/change the scheduler policy and RT priority ++ * @pid: the pid in question. ++ * @policy: new policy. ++ * ++ * Return: 0 on success. An error code otherwise. ++ * @param: structure containing the new RT priority. ++ */ ++SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, struct sched_param __user *, param) ++{ ++ if (policy < 0) ++ return -EINVAL; ++ ++ return do_sched_setscheduler(pid, policy, param); ++} ++ ++/** ++ * sys_sched_setparam - set/change the RT priority of a thread ++ * @pid: the pid in question. ++ * @param: structure containing the new RT priority. ++ * ++ * Return: 0 on success. An error code otherwise. ++ */ ++SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) ++{ ++ return do_sched_setscheduler(pid, SETPARAM_POLICY, param); ++} ++ ++/** ++ * sys_sched_setattr - same as above, but with extended sched_attr ++ * @pid: the pid in question. ++ * @uattr: structure containing the extended parameters. ++ */ ++SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, ++ unsigned int, flags) ++{ ++ struct sched_attr attr; ++ struct task_struct *p; ++ int retval; ++ ++ if (!uattr || pid < 0 || flags) ++ return -EINVAL; ++ ++ retval = sched_copy_attr(uattr, &attr); ++ if (retval) ++ return retval; ++ ++ if ((int)attr.sched_policy < 0) ++ return -EINVAL; ++ ++ rcu_read_lock(); ++ retval = -ESRCH; ++ p = find_process_by_pid(pid); ++ if (likely(p)) ++ get_task_struct(p); ++ rcu_read_unlock(); ++ ++ if (likely(p)) { ++ retval = sched_setattr(p, &attr); ++ put_task_struct(p); ++ } ++ ++ return retval; ++} ++ ++/** ++ * sys_sched_getscheduler - get the policy (scheduling class) of a thread ++ * @pid: the pid in question. ++ * ++ * Return: On success, the policy of the thread. Otherwise, a negative error ++ * code. ++ */ ++SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) ++{ ++ struct task_struct *p; ++ int retval = -EINVAL; ++ ++ if (pid < 0) ++ goto out_nounlock; ++ ++ retval = -ESRCH; ++ rcu_read_lock(); ++ p = find_process_by_pid(pid); ++ if (p) { ++ retval = security_task_getscheduler(p); ++ if (!retval) ++ retval = p->policy; ++ } ++ rcu_read_unlock(); ++ ++out_nounlock: ++ return retval; ++} ++ ++/** ++ * sys_sched_getscheduler - get the RT priority of a thread ++ * @pid: the pid in question. ++ * @param: structure containing the RT priority. ++ * ++ * Return: On success, 0 and the RT priority is in @param. Otherwise, an error ++ * code. ++ */ ++SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) ++{ ++ struct sched_param lp = { .sched_priority = 0 }; ++ struct task_struct *p; ++ int retval = -EINVAL; ++ ++ if (!param || pid < 0) ++ goto out_nounlock; ++ ++ rcu_read_lock(); ++ p = find_process_by_pid(pid); ++ retval = -ESRCH; ++ if (!p) ++ goto out_unlock; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ goto out_unlock; ++ ++ if (task_has_rt_policy(p)) ++ lp.sched_priority = p->rt_priority; ++ rcu_read_unlock(); ++ ++ /* ++ * This one might sleep, we cannot do it with a spinlock held ... ++ */ ++ retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; ++ ++out_nounlock: ++ return retval; ++ ++out_unlock: ++ rcu_read_unlock(); ++ return retval; ++} ++ ++/* ++ * Copy the kernel size attribute structure (which might be larger ++ * than what user-space knows about) to user-space. ++ * ++ * Note that all cases are valid: user-space buffer can be larger or ++ * smaller than the kernel-space buffer. The usual case is that both ++ * have the same size. ++ */ ++static int ++sched_attr_copy_to_user(struct sched_attr __user *uattr, ++ struct sched_attr *kattr, ++ unsigned int usize) ++{ ++ unsigned int ksize = sizeof(*kattr); ++ ++ if (!access_ok(uattr, usize)) ++ return -EFAULT; ++ ++ /* ++ * sched_getattr() ABI forwards and backwards compatibility: ++ * ++ * If usize == ksize then we just copy everything to user-space and all is good. ++ * ++ * If usize < ksize then we only copy as much as user-space has space for, ++ * this keeps ABI compatibility as well. We skip the rest. ++ * ++ * If usize > ksize then user-space is using a newer version of the ABI, ++ * which part the kernel doesn't know about. Just ignore it - tooling can ++ * detect the kernel's knowledge of attributes from the attr->size value ++ * which is set to ksize in this case. ++ */ ++ kattr->size = min(usize, ksize); ++ ++ if (copy_to_user(uattr, kattr, kattr->size)) ++ return -EFAULT; ++ ++ return 0; ++} ++ ++/** ++ * sys_sched_getattr - similar to sched_getparam, but with sched_attr ++ * @pid: the pid in question. ++ * @uattr: structure containing the extended parameters. ++ * @usize: sizeof(attr) for fwd/bwd comp. ++ * @flags: for future extension. ++ */ ++SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, ++ unsigned int, usize, unsigned int, flags) ++{ ++ struct sched_attr kattr = { }; ++ struct task_struct *p; ++ int retval; ++ ++ if (!uattr || pid < 0 || usize > PAGE_SIZE || ++ usize < SCHED_ATTR_SIZE_VER0 || flags) ++ return -EINVAL; ++ ++ rcu_read_lock(); ++ p = find_process_by_pid(pid); ++ retval = -ESRCH; ++ if (!p) ++ goto out_unlock; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ goto out_unlock; ++ ++ kattr.sched_policy = p->policy; ++ if (p->sched_reset_on_fork) ++ kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; ++ if (task_has_rt_policy(p)) ++ kattr.sched_priority = p->rt_priority; ++ else ++ kattr.sched_nice = task_nice(p); ++ ++#ifdef CONFIG_UCLAMP_TASK ++ kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value; ++ kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value; ++#endif ++ ++ rcu_read_unlock(); ++ ++ return sched_attr_copy_to_user(uattr, &kattr, usize); ++ ++out_unlock: ++ rcu_read_unlock(); ++ return retval; ++} ++ ++long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) ++{ ++ cpumask_var_t cpus_allowed, new_mask; ++ struct task_struct *p; ++ int retval; ++ ++ rcu_read_lock(); ++ ++ p = find_process_by_pid(pid); ++ if (!p) { ++ rcu_read_unlock(); ++ return -ESRCH; ++ } ++ ++ /* Prevent p going away */ ++ get_task_struct(p); ++ rcu_read_unlock(); ++ ++ if (p->flags & PF_NO_SETAFFINITY) { ++ retval = -EINVAL; ++ goto out_put_task; ++ } ++ if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { ++ retval = -ENOMEM; ++ goto out_put_task; ++ } ++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { ++ retval = -ENOMEM; ++ goto out_free_cpus_allowed; ++ } ++ retval = -EPERM; ++ if (!check_same_owner(p)) { ++ rcu_read_lock(); ++ if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { ++ rcu_read_unlock(); ++ goto out_free_new_mask; ++ } ++ rcu_read_unlock(); ++ } ++ ++ retval = security_task_setscheduler(p); ++ if (retval) ++ goto out_free_new_mask; ++ ++ cpuset_cpus_allowed(p, cpus_allowed); ++ cpumask_and(new_mask, in_mask, cpus_allowed); ++ ++again: ++ retval = __set_cpus_allowed_ptr(p, new_mask, SCA_CHECK); ++ ++ if (!retval) { ++ cpuset_cpus_allowed(p, cpus_allowed); ++ if (!cpumask_subset(new_mask, cpus_allowed)) { ++ /* ++ * We must have raced with a concurrent cpuset ++ * update. Just reset the cpus_allowed to the ++ * cpuset's cpus_allowed ++ */ ++ cpumask_copy(new_mask, cpus_allowed); ++ goto again; ++ } ++ } ++out_free_new_mask: ++ free_cpumask_var(new_mask); ++out_free_cpus_allowed: ++ free_cpumask_var(cpus_allowed); ++out_put_task: ++ put_task_struct(p); ++ return retval; ++} ++ ++static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, ++ struct cpumask *new_mask) ++{ ++ if (len < cpumask_size()) ++ cpumask_clear(new_mask); ++ else if (len > cpumask_size()) ++ len = cpumask_size(); ++ ++ return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; ++} ++ ++/** ++ * sys_sched_setaffinity - set the CPU affinity of a process ++ * @pid: pid of the process ++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr ++ * @user_mask_ptr: user-space pointer to the new CPU mask ++ * ++ * Return: 0 on success. An error code otherwise. ++ */ ++SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, ++ unsigned long __user *, user_mask_ptr) ++{ ++ cpumask_var_t new_mask; ++ int retval; ++ ++ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) ++ return -ENOMEM; ++ ++ retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); ++ if (retval == 0) ++ retval = sched_setaffinity(pid, new_mask); ++ free_cpumask_var(new_mask); ++ return retval; ++} ++ ++long sched_getaffinity(pid_t pid, cpumask_t *mask) ++{ ++ struct task_struct *p; ++ raw_spinlock_t *lock; ++ unsigned long flags; ++ int retval; ++ ++ rcu_read_lock(); ++ ++ retval = -ESRCH; ++ p = find_process_by_pid(pid); ++ if (!p) ++ goto out_unlock; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ goto out_unlock; ++ ++ task_access_lock_irqsave(p, &lock, &flags); ++ cpumask_and(mask, &p->cpus_mask, cpu_active_mask); ++ task_access_unlock_irqrestore(p, lock, &flags); ++ ++out_unlock: ++ rcu_read_unlock(); ++ ++ return retval; ++} ++ ++/** ++ * sys_sched_getaffinity - get the CPU affinity of a process ++ * @pid: pid of the process ++ * @len: length in bytes of the bitmask pointed to by user_mask_ptr ++ * @user_mask_ptr: user-space pointer to hold the current CPU mask ++ * ++ * Return: size of CPU mask copied to user_mask_ptr on success. An ++ * error code otherwise. ++ */ ++SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, ++ unsigned long __user *, user_mask_ptr) ++{ ++ int ret; ++ cpumask_var_t mask; ++ ++ if ((len * BITS_PER_BYTE) < nr_cpu_ids) ++ return -EINVAL; ++ if (len & (sizeof(unsigned long)-1)) ++ return -EINVAL; ++ ++ if (!alloc_cpumask_var(&mask, GFP_KERNEL)) ++ return -ENOMEM; ++ ++ ret = sched_getaffinity(pid, mask); ++ if (ret == 0) { ++ unsigned int retlen = min_t(size_t, len, cpumask_size()); ++ ++ if (copy_to_user(user_mask_ptr, mask, retlen)) ++ ret = -EFAULT; ++ else ++ ret = retlen; ++ } ++ free_cpumask_var(mask); ++ ++ return ret; ++} ++ ++static void do_sched_yield(void) ++{ ++ struct rq *rq; ++ struct rq_flags rf; ++ ++ if (!sched_yield_type) ++ return; ++ ++ rq = this_rq_lock_irq(&rf); ++ ++ schedstat_inc(rq->yld_count); ++ ++ if (1 == sched_yield_type) { ++ if (!rt_task(current)) ++ do_sched_yield_type_1(current, rq); ++ } else if (2 == sched_yield_type) { ++ if (rq->nr_running > 1) ++ rq->skip = current; ++ } ++ ++ preempt_disable(); ++ raw_spin_unlock_irq(&rq->lock); ++ sched_preempt_enable_no_resched(); ++ ++ schedule(); ++} ++ ++/** ++ * sys_sched_yield - yield the current processor to other threads. ++ * ++ * This function yields the current CPU to other tasks. If there are no ++ * other threads running on this CPU then this function will return. ++ * ++ * Return: 0. ++ */ ++SYSCALL_DEFINE0(sched_yield) ++{ ++ do_sched_yield(); ++ return 0; ++} ++ ++#if !defined(CONFIG_PREEMPTION) || defined(CONFIG_PREEMPT_DYNAMIC) ++int __sched __cond_resched(void) ++{ ++ if (should_resched(0)) { ++ preempt_schedule_common(); ++ return 1; ++ } ++#ifndef CONFIG_PREEMPT_RCU ++ rcu_all_qs(); ++#endif ++ return 0; ++} ++EXPORT_SYMBOL(__cond_resched); ++#endif ++ ++#ifdef CONFIG_PREEMPT_DYNAMIC ++DEFINE_STATIC_CALL_RET0(cond_resched, __cond_resched); ++EXPORT_STATIC_CALL_TRAMP(cond_resched); ++ ++DEFINE_STATIC_CALL_RET0(might_resched, __cond_resched); ++EXPORT_STATIC_CALL_TRAMP(might_resched); ++#endif ++ ++/* ++ * __cond_resched_lock() - if a reschedule is pending, drop the given lock, ++ * call schedule, and on return reacquire the lock. ++ * ++ * This works OK both with and without CONFIG_PREEMPTION. We do strange low-level ++ * operations here to prevent schedule() from being called twice (once via ++ * spin_unlock(), once by hand). ++ */ ++int __cond_resched_lock(spinlock_t *lock) ++{ ++ int resched = should_resched(PREEMPT_LOCK_OFFSET); ++ int ret = 0; ++ ++ lockdep_assert_held(lock); ++ ++ if (spin_needbreak(lock) || resched) { ++ spin_unlock(lock); ++ if (resched) ++ preempt_schedule_common(); ++ else ++ cpu_relax(); ++ ret = 1; ++ spin_lock(lock); ++ } ++ return ret; ++} ++EXPORT_SYMBOL(__cond_resched_lock); ++ ++int __cond_resched_rwlock_read(rwlock_t *lock) ++{ ++ int resched = should_resched(PREEMPT_LOCK_OFFSET); ++ int ret = 0; ++ ++ lockdep_assert_held_read(lock); ++ ++ if (rwlock_needbreak(lock) || resched) { ++ read_unlock(lock); ++ if (resched) ++ preempt_schedule_common(); ++ else ++ cpu_relax(); ++ ret = 1; ++ read_lock(lock); ++ } ++ return ret; ++} ++EXPORT_SYMBOL(__cond_resched_rwlock_read); ++ ++int __cond_resched_rwlock_write(rwlock_t *lock) ++{ ++ int resched = should_resched(PREEMPT_LOCK_OFFSET); ++ int ret = 0; ++ ++ lockdep_assert_held_write(lock); ++ ++ if (rwlock_needbreak(lock) || resched) { ++ write_unlock(lock); ++ if (resched) ++ preempt_schedule_common(); ++ else ++ cpu_relax(); ++ ret = 1; ++ write_lock(lock); ++ } ++ return ret; ++} ++EXPORT_SYMBOL(__cond_resched_rwlock_write); ++ ++/** ++ * yield - yield the current processor to other threads. ++ * ++ * Do not ever use this function, there's a 99% chance you're doing it wrong. ++ * ++ * The scheduler is at all times free to pick the calling task as the most ++ * eligible task to run, if removing the yield() call from your code breaks ++ * it, it's already broken. ++ * ++ * Typical broken usage is: ++ * ++ * while (!event) ++ * yield(); ++ * ++ * where one assumes that yield() will let 'the other' process run that will ++ * make event true. If the current task is a SCHED_FIFO task that will never ++ * happen. Never use yield() as a progress guarantee!! ++ * ++ * If you want to use yield() to wait for something, use wait_event(). ++ * If you want to use yield() to be 'nice' for others, use cond_resched(). ++ * If you still want to use yield(), do not! ++ */ ++void __sched yield(void) ++{ ++ set_current_state(TASK_RUNNING); ++ do_sched_yield(); ++} ++EXPORT_SYMBOL(yield); ++ ++/** ++ * yield_to - yield the current processor to another thread in ++ * your thread group, or accelerate that thread toward the ++ * processor it's on. ++ * @p: target task ++ * @preempt: whether task preemption is allowed or not ++ * ++ * It's the caller's job to ensure that the target task struct ++ * can't go away on us before we can do any checks. ++ * ++ * In Alt schedule FW, yield_to is not supported. ++ * ++ * Return: ++ * true (>0) if we indeed boosted the target task. ++ * false (0) if we failed to boost the target. ++ * -ESRCH if there's no task to yield to. ++ */ ++int __sched yield_to(struct task_struct *p, bool preempt) ++{ ++ return 0; ++} ++EXPORT_SYMBOL_GPL(yield_to); ++ ++int io_schedule_prepare(void) ++{ ++ int old_iowait = current->in_iowait; ++ ++ current->in_iowait = 1; ++ blk_schedule_flush_plug(current); ++ ++ return old_iowait; ++} ++ ++void io_schedule_finish(int token) ++{ ++ current->in_iowait = token; ++} ++ ++/* ++ * This task is about to go to sleep on IO. Increment rq->nr_iowait so ++ * that process accounting knows that this is a task in IO wait state. ++ * ++ * But don't do that if it is a deliberate, throttling IO wait (this task ++ * has set its backing_dev_info: the queue against which it should throttle) ++ */ ++ ++long __sched io_schedule_timeout(long timeout) ++{ ++ int token; ++ long ret; ++ ++ token = io_schedule_prepare(); ++ ret = schedule_timeout(timeout); ++ io_schedule_finish(token); ++ ++ return ret; ++} ++EXPORT_SYMBOL(io_schedule_timeout); ++ ++void __sched io_schedule(void) ++{ ++ int token; ++ ++ token = io_schedule_prepare(); ++ schedule(); ++ io_schedule_finish(token); ++} ++EXPORT_SYMBOL(io_schedule); ++ ++/** ++ * sys_sched_get_priority_max - return maximum RT priority. ++ * @policy: scheduling class. ++ * ++ * Return: On success, this syscall returns the maximum ++ * rt_priority that can be used by a given scheduling class. ++ * On failure, a negative error code is returned. ++ */ ++SYSCALL_DEFINE1(sched_get_priority_max, int, policy) ++{ ++ int ret = -EINVAL; ++ ++ switch (policy) { ++ case SCHED_FIFO: ++ case SCHED_RR: ++ ret = MAX_RT_PRIO - 1; ++ break; ++ case SCHED_NORMAL: ++ case SCHED_BATCH: ++ case SCHED_IDLE: ++ ret = 0; ++ break; ++ } ++ return ret; ++} ++ ++/** ++ * sys_sched_get_priority_min - return minimum RT priority. ++ * @policy: scheduling class. ++ * ++ * Return: On success, this syscall returns the minimum ++ * rt_priority that can be used by a given scheduling class. ++ * On failure, a negative error code is returned. ++ */ ++SYSCALL_DEFINE1(sched_get_priority_min, int, policy) ++{ ++ int ret = -EINVAL; ++ ++ switch (policy) { ++ case SCHED_FIFO: ++ case SCHED_RR: ++ ret = 1; ++ break; ++ case SCHED_NORMAL: ++ case SCHED_BATCH: ++ case SCHED_IDLE: ++ ret = 0; ++ break; ++ } ++ return ret; ++} ++ ++static int sched_rr_get_interval(pid_t pid, struct timespec64 *t) ++{ ++ struct task_struct *p; ++ int retval; ++ ++ alt_sched_debug(); ++ ++ if (pid < 0) ++ return -EINVAL; ++ ++ retval = -ESRCH; ++ rcu_read_lock(); ++ p = find_process_by_pid(pid); ++ if (!p) ++ goto out_unlock; ++ ++ retval = security_task_getscheduler(p); ++ if (retval) ++ goto out_unlock; ++ rcu_read_unlock(); ++ ++ *t = ns_to_timespec64(sched_timeslice_ns); ++ return 0; ++ ++out_unlock: ++ rcu_read_unlock(); ++ return retval; ++} ++ ++/** ++ * sys_sched_rr_get_interval - return the default timeslice of a process. ++ * @pid: pid of the process. ++ * @interval: userspace pointer to the timeslice value. ++ * ++ * ++ * Return: On success, 0 and the timeslice is in @interval. Otherwise, ++ * an error code. ++ */ ++SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, ++ struct __kernel_timespec __user *, interval) ++{ ++ struct timespec64 t; ++ int retval = sched_rr_get_interval(pid, &t); ++ ++ if (retval == 0) ++ retval = put_timespec64(&t, interval); ++ ++ return retval; ++} ++ ++#ifdef CONFIG_COMPAT_32BIT_TIME ++SYSCALL_DEFINE2(sched_rr_get_interval_time32, pid_t, pid, ++ struct old_timespec32 __user *, interval) ++{ ++ struct timespec64 t; ++ int retval = sched_rr_get_interval(pid, &t); ++ ++ if (retval == 0) ++ retval = put_old_timespec32(&t, interval); ++ return retval; ++} ++#endif ++ ++void sched_show_task(struct task_struct *p) ++{ ++ unsigned long free = 0; ++ int ppid; ++ ++ if (!try_get_task_stack(p)) ++ return; ++ ++ pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p)); ++ ++ if (p->state == TASK_RUNNING) ++ pr_cont(" running task "); ++#ifdef CONFIG_DEBUG_STACK_USAGE ++ free = stack_not_used(p); ++#endif ++ ppid = 0; ++ rcu_read_lock(); ++ if (pid_alive(p)) ++ ppid = task_pid_nr(rcu_dereference(p->real_parent)); ++ rcu_read_unlock(); ++ pr_cont(" stack:%5lu pid:%5d ppid:%6d flags:0x%08lx\n", ++ free, task_pid_nr(p), ppid, ++ (unsigned long)task_thread_info(p)->flags); ++ ++ print_worker_info(KERN_INFO, p); ++ print_stop_info(KERN_INFO, p); ++ show_stack(p, NULL, KERN_INFO); ++ put_task_stack(p); ++} ++EXPORT_SYMBOL_GPL(sched_show_task); ++ ++static inline bool ++state_filter_match(unsigned long state_filter, struct task_struct *p) ++{ ++ /* no filter, everything matches */ ++ if (!state_filter) ++ return true; ++ ++ /* filter, but doesn't match */ ++ if (!(p->state & state_filter)) ++ return false; ++ ++ /* ++ * When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows ++ * TASK_KILLABLE). ++ */ ++ if (state_filter == TASK_UNINTERRUPTIBLE && p->state == TASK_IDLE) ++ return false; ++ ++ return true; ++} ++ ++ ++void show_state_filter(unsigned long state_filter) ++{ ++ struct task_struct *g, *p; ++ ++ rcu_read_lock(); ++ for_each_process_thread(g, p) { ++ /* ++ * reset the NMI-timeout, listing all files on a slow ++ * console might take a lot of time: ++ * Also, reset softlockup watchdogs on all CPUs, because ++ * another CPU might be blocked waiting for us to process ++ * an IPI. ++ */ ++ touch_nmi_watchdog(); ++ touch_all_softlockup_watchdogs(); ++ if (state_filter_match(state_filter, p)) ++ sched_show_task(p); ++ } ++ ++#ifdef CONFIG_SCHED_DEBUG ++ /* TODO: Alt schedule FW should support this ++ if (!state_filter) ++ sysrq_sched_debug_show(); ++ */ ++#endif ++ rcu_read_unlock(); ++ /* ++ * Only show locks if all tasks are dumped: ++ */ ++ if (!state_filter) ++ debug_show_all_locks(); ++} ++ ++void dump_cpu_task(int cpu) ++{ ++ pr_info("Task dump for CPU %d:\n", cpu); ++ sched_show_task(cpu_curr(cpu)); ++} ++ ++/** ++ * init_idle - set up an idle thread for a given CPU ++ * @idle: task in question ++ * @cpu: CPU the idle task belongs to ++ * ++ * NOTE: this function does not set the idle thread's NEED_RESCHED ++ * flag, to make booting more robust. ++ */ ++void init_idle(struct task_struct *idle, int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ __sched_fork(0, idle); ++ ++ raw_spin_lock_irqsave(&idle->pi_lock, flags); ++ raw_spin_lock(&rq->lock); ++ update_rq_clock(rq); ++ ++ idle->last_ran = rq->clock_task; ++ idle->state = TASK_RUNNING; ++ idle->flags |= PF_IDLE; ++ sched_queue_init_idle(rq, idle); ++ ++ scs_task_reset(idle); ++ kasan_unpoison_task_stack(idle); ++ ++#ifdef CONFIG_SMP ++ /* ++ * It's possible that init_idle() gets called multiple times on a task, ++ * in that case do_set_cpus_allowed() will not do the right thing. ++ * ++ * And since this is boot we can forgo the serialisation. ++ */ ++ set_cpus_allowed_common(idle, cpumask_of(cpu)); ++#endif ++ ++ /* Silence PROVE_RCU */ ++ rcu_read_lock(); ++ __set_task_cpu(idle, cpu); ++ rcu_read_unlock(); ++ ++ rq->idle = idle; ++ rcu_assign_pointer(rq->curr, idle); ++ idle->on_cpu = 1; ++ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&idle->pi_lock, flags); ++ ++ /* Set the preempt count _outside_ the spinlocks! */ ++ init_idle_preempt_count(idle, cpu); ++ ++ ftrace_graph_init_idle_task(idle, cpu); ++ vtime_init_idle(idle, cpu); ++#ifdef CONFIG_SMP ++ sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); ++#endif ++} ++ ++#ifdef CONFIG_SMP ++ ++int cpuset_cpumask_can_shrink(const struct cpumask __maybe_unused *cur, ++ const struct cpumask __maybe_unused *trial) ++{ ++ return 1; ++} ++ ++int task_can_attach(struct task_struct *p, ++ const struct cpumask *cs_cpus_allowed) ++{ ++ int ret = 0; ++ ++ /* ++ * Kthreads which disallow setaffinity shouldn't be moved ++ * to a new cpuset; we don't want to change their CPU ++ * affinity and isolating such threads by their set of ++ * allowed nodes is unnecessary. Thus, cpusets are not ++ * applicable for such threads. This prevents checking for ++ * success of set_cpus_allowed_ptr() on all attached tasks ++ * before cpus_mask may be changed. ++ */ ++ if (p->flags & PF_NO_SETAFFINITY) ++ ret = -EINVAL; ++ ++ return ret; ++} ++ ++bool sched_smp_initialized __read_mostly; ++ ++#ifdef CONFIG_HOTPLUG_CPU ++/* ++ * Ensures that the idle task is using init_mm right before its CPU goes ++ * offline. ++ */ ++void idle_task_exit(void) ++{ ++ struct mm_struct *mm = current->active_mm; ++ ++ BUG_ON(current != this_rq()->idle); ++ ++ if (mm != &init_mm) { ++ switch_mm(mm, &init_mm, current); ++ finish_arch_post_lock_switch(); ++ } ++ ++ /* finish_cpu(), as ran on the BP, will clean up the active_mm state */ ++} ++ ++static int __balance_push_cpu_stop(void *arg) ++{ ++ struct task_struct *p = arg; ++ struct rq *rq = this_rq(); ++ struct rq_flags rf; ++ int cpu; ++ ++ raw_spin_lock_irq(&p->pi_lock); ++ rq_lock(rq, &rf); ++ ++ update_rq_clock(rq); ++ ++ if (task_rq(p) == rq && task_on_rq_queued(p)) { ++ cpu = select_fallback_rq(rq->cpu, p); ++ rq = __migrate_task(rq, p, cpu); ++ } ++ ++ rq_unlock(rq, &rf); ++ raw_spin_unlock_irq(&p->pi_lock); ++ ++ put_task_struct(p); ++ ++ return 0; ++} ++ ++static DEFINE_PER_CPU(struct cpu_stop_work, push_work); ++ ++/* ++ * Ensure we only run per-cpu kthreads once the CPU goes !active. ++ */ ++static void balance_push(struct rq *rq) ++{ ++ struct task_struct *push_task = rq->curr; ++ ++ lockdep_assert_held(&rq->lock); ++ SCHED_WARN_ON(rq->cpu != smp_processor_id()); ++ /* ++ * Ensure the thing is persistent until balance_push_set(.on = false); ++ */ ++ rq->balance_callback = &balance_push_callback; ++ ++ /* ++ * Both the cpu-hotplug and stop task are in this case and are ++ * required to complete the hotplug process. ++ * ++ * XXX: the idle task does not match kthread_is_per_cpu() due to ++ * histerical raisins. ++ */ ++ if (rq->idle == push_task || ++ ((push_task->flags & PF_KTHREAD) && kthread_is_per_cpu(push_task)) || ++ is_migration_disabled(push_task)) { ++ ++ /* ++ * If this is the idle task on the outgoing CPU try to wake ++ * up the hotplug control thread which might wait for the ++ * last task to vanish. The rcuwait_active() check is ++ * accurate here because the waiter is pinned on this CPU ++ * and can't obviously be running in parallel. ++ * ++ * On RT kernels this also has to check whether there are ++ * pinned and scheduled out tasks on the runqueue. They ++ * need to leave the migrate disabled section first. ++ */ ++ if (!rq->nr_running && !rq_has_pinned_tasks(rq) && ++ rcuwait_active(&rq->hotplug_wait)) { ++ raw_spin_unlock(&rq->lock); ++ rcuwait_wake_up(&rq->hotplug_wait); ++ raw_spin_lock(&rq->lock); ++ } ++ return; ++ } ++ ++ get_task_struct(push_task); ++ /* ++ * Temporarily drop rq->lock such that we can wake-up the stop task. ++ * Both preemption and IRQs are still disabled. ++ */ ++ raw_spin_unlock(&rq->lock); ++ stop_one_cpu_nowait(rq->cpu, __balance_push_cpu_stop, push_task, ++ this_cpu_ptr(&push_work)); ++ /* ++ * At this point need_resched() is true and we'll take the loop in ++ * schedule(). The next pick is obviously going to be the stop task ++ * which kthread_is_per_cpu() and will push this task away. ++ */ ++ raw_spin_lock(&rq->lock); ++} ++ ++static void balance_push_set(int cpu, bool on) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ struct rq_flags rf; ++ ++ rq_lock_irqsave(rq, &rf); ++ rq->balance_push = on; ++ if (on) { ++ WARN_ON_ONCE(rq->balance_callback); ++ rq->balance_callback = &balance_push_callback; ++ } else if (rq->balance_callback == &balance_push_callback) { ++ rq->balance_callback = NULL; ++ } ++ rq_unlock_irqrestore(rq, &rf); ++} ++ ++/* ++ * Invoked from a CPUs hotplug control thread after the CPU has been marked ++ * inactive. All tasks which are not per CPU kernel threads are either ++ * pushed off this CPU now via balance_push() or placed on a different CPU ++ * during wakeup. Wait until the CPU is quiescent. ++ */ ++static void balance_hotplug_wait(void) ++{ ++ struct rq *rq = this_rq(); ++ ++ rcuwait_wait_event(&rq->hotplug_wait, ++ rq->nr_running == 1 && !rq_has_pinned_tasks(rq), ++ TASK_UNINTERRUPTIBLE); ++} ++ ++#else ++ ++static void balance_push(struct rq *rq) ++{ ++} ++ ++static void balance_push_set(int cpu, bool on) ++{ ++} ++ ++static inline void balance_hotplug_wait(void) ++{ ++} ++#endif /* CONFIG_HOTPLUG_CPU */ ++ ++static void set_rq_offline(struct rq *rq) ++{ ++ if (rq->online) ++ rq->online = false; ++} ++ ++static void set_rq_online(struct rq *rq) ++{ ++ if (!rq->online) ++ rq->online = true; ++} ++ ++/* ++ * used to mark begin/end of suspend/resume: ++ */ ++static int num_cpus_frozen; ++ ++/* ++ * Update cpusets according to cpu_active mask. If cpusets are ++ * disabled, cpuset_update_active_cpus() becomes a simple wrapper ++ * around partition_sched_domains(). ++ * ++ * If we come here as part of a suspend/resume, don't touch cpusets because we ++ * want to restore it back to its original state upon resume anyway. ++ */ ++static void cpuset_cpu_active(void) ++{ ++ if (cpuhp_tasks_frozen) { ++ /* ++ * num_cpus_frozen tracks how many CPUs are involved in suspend ++ * resume sequence. As long as this is not the last online ++ * operation in the resume sequence, just build a single sched ++ * domain, ignoring cpusets. ++ */ ++ partition_sched_domains(1, NULL, NULL); ++ if (--num_cpus_frozen) ++ return; ++ /* ++ * This is the last CPU online operation. So fall through and ++ * restore the original sched domains by considering the ++ * cpuset configurations. ++ */ ++ cpuset_force_rebuild(); ++ } ++ ++ cpuset_update_active_cpus(); ++} ++ ++static int cpuset_cpu_inactive(unsigned int cpu) ++{ ++ if (!cpuhp_tasks_frozen) { ++ cpuset_update_active_cpus(); ++ } else { ++ num_cpus_frozen++; ++ partition_sched_domains(1, NULL, NULL); ++ } ++ return 0; ++} ++ ++int sched_cpu_activate(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ /* ++ * Make sure that when the hotplug state machine does a roll-back ++ * we clear balance_push. Ideally that would happen earlier... ++ */ ++ balance_push_set(cpu, false); ++ ++#ifdef CONFIG_SCHED_SMT ++ /* ++ * When going up, increment the number of cores with SMT present. ++ */ ++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) ++ static_branch_inc_cpuslocked(&sched_smt_present); ++#endif ++ set_cpu_active(cpu, true); ++ ++ if (sched_smp_initialized) ++ cpuset_cpu_active(); ++ ++ /* ++ * Put the rq online, if not already. This happens: ++ * ++ * 1) In the early boot process, because we build the real domains ++ * after all cpus have been brought up. ++ * ++ * 2) At runtime, if cpuset_cpu_active() fails to rebuild the ++ * domains. ++ */ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ set_rq_online(rq); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++ return 0; ++} ++ ++int sched_cpu_deactivate(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ int ret; ++ ++ set_cpu_active(cpu, false); ++ ++ /* ++ * From this point forward, this CPU will refuse to run any task that ++ * is not: migrate_disable() or KTHREAD_IS_PER_CPU, and will actively ++ * push those tasks away until this gets cleared, see ++ * sched_cpu_dying(). ++ */ ++ balance_push_set(cpu, true); ++ ++ /* ++ * We've cleared cpu_active_mask, wait for all preempt-disabled and RCU ++ * users of this state to go away such that all new such users will ++ * observe it. ++ * ++ * Specifically, we rely on ttwu to no longer target this CPU, see ++ * ttwu_queue_cond() and is_cpu_allowed(). ++ * ++ * Do sync before park smpboot threads to take care the rcu boost case. ++ */ ++ synchronize_rcu(); ++ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ update_rq_clock(rq); ++ set_rq_offline(rq); ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++#ifdef CONFIG_SCHED_SMT ++ /* ++ * When going down, decrement the number of cores with SMT present. ++ */ ++ if (cpumask_weight(cpu_smt_mask(cpu)) == 2) { ++ static_branch_dec_cpuslocked(&sched_smt_present); ++ if (!static_branch_likely(&sched_smt_present)) ++ cpumask_clear(&sched_sg_idle_mask); ++ } ++#endif ++ ++ if (!sched_smp_initialized) ++ return 0; ++ ++ ret = cpuset_cpu_inactive(cpu); ++ if (ret) { ++ balance_push_set(cpu, false); ++ set_cpu_active(cpu, true); ++ return ret; ++ } ++ ++ return 0; ++} ++ ++static void sched_rq_cpu_starting(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ ++ rq->calc_load_update = calc_load_update; ++} ++ ++int sched_cpu_starting(unsigned int cpu) ++{ ++ sched_rq_cpu_starting(cpu); ++ sched_tick_start(cpu); ++ return 0; ++} ++ ++#ifdef CONFIG_HOTPLUG_CPU ++ ++/* ++ * Invoked immediately before the stopper thread is invoked to bring the ++ * CPU down completely. At this point all per CPU kthreads except the ++ * hotplug thread (current) and the stopper thread (inactive) have been ++ * either parked or have been unbound from the outgoing CPU. Ensure that ++ * any of those which might be on the way out are gone. ++ * ++ * If after this point a bound task is being woken on this CPU then the ++ * responsible hotplug callback has failed to do it's job. ++ * sched_cpu_dying() will catch it with the appropriate fireworks. ++ */ ++int sched_cpu_wait_empty(unsigned int cpu) ++{ ++ balance_hotplug_wait(); ++ return 0; ++} ++ ++/* ++ * Since this CPU is going 'away' for a while, fold any nr_active delta we ++ * might have. Called from the CPU stopper task after ensuring that the ++ * stopper is the last running task on the CPU, so nr_active count is ++ * stable. We need to take the teardown thread which is calling this into ++ * account, so we hand in adjust = 1 to the load calculation. ++ * ++ * Also see the comment "Global load-average calculations". ++ */ ++static void calc_load_migrate(struct rq *rq) ++{ ++ long delta = calc_load_fold_active(rq, 1); ++ ++ if (delta) ++ atomic_long_add(delta, &calc_load_tasks); ++} ++ ++static void dump_rq_tasks(struct rq *rq, const char *loglvl) ++{ ++ struct task_struct *g, *p; ++ int cpu = cpu_of(rq); ++ ++ lockdep_assert_held(&rq->lock); ++ ++ printk("%sCPU%d enqueued tasks (%u total):\n", loglvl, cpu, rq->nr_running); ++ for_each_process_thread(g, p) { ++ if (task_cpu(p) != cpu) ++ continue; ++ ++ if (!task_on_rq_queued(p)) ++ continue; ++ ++ printk("%s\tpid: %d, name: %s\n", loglvl, p->pid, p->comm); ++ } ++} ++ ++int sched_cpu_dying(unsigned int cpu) ++{ ++ struct rq *rq = cpu_rq(cpu); ++ unsigned long flags; ++ ++ /* Handle pending wakeups and then migrate everything off */ ++ sched_tick_stop(cpu); ++ ++ raw_spin_lock_irqsave(&rq->lock, flags); ++ if (rq->nr_running != 1 || rq_has_pinned_tasks(rq)) { ++ WARN(true, "Dying CPU not properly vacated!"); ++ dump_rq_tasks(rq, KERN_WARNING); ++ } ++ raw_spin_unlock_irqrestore(&rq->lock, flags); ++ ++ /* ++ * Now that the CPU is offline, make sure we're welcome ++ * to new tasks once we come back up. ++ */ ++ balance_push_set(cpu, false); ++ ++ calc_load_migrate(rq); ++ hrtick_clear(rq); ++ return 0; ++} ++#endif ++ ++#ifdef CONFIG_SMP ++static void sched_init_topology_cpumask_early(void) ++{ ++ int cpu; ++ cpumask_t *tmp; ++ ++ for_each_possible_cpu(cpu) { ++ /* init affinity masks */ ++ tmp = per_cpu(sched_cpu_affinity_masks, cpu); ++ ++ cpumask_copy(tmp, cpumask_of(cpu)); ++ tmp++; ++ cpumask_copy(tmp, cpu_possible_mask); ++ cpumask_clear_cpu(cpu, tmp); ++ per_cpu(sched_cpu_affinity_end_mask, cpu) = ++tmp; ++ /* init topo masks */ ++ tmp = per_cpu(sched_cpu_topo_masks, cpu); ++ ++ cpumask_copy(tmp, cpumask_of(cpu)); ++ tmp++; ++ cpumask_copy(tmp, cpu_possible_mask); ++ per_cpu(sched_cpu_llc_mask, cpu) = tmp; ++ /*per_cpu(sd_llc_id, cpu) = cpu;*/ ++ } ++} ++ ++#define TOPOLOGY_CPUMASK(name, mask, last) \ ++ if (cpumask_and(chk, chk, mask)) { \ ++ cpumask_copy(topo, mask); \ ++ printk(KERN_INFO "sched: cpu#%02d affinity: 0x%08lx topo: 0x%08lx - "#name,\ ++ cpu, (chk++)->bits[0], (topo++)->bits[0]); \ ++ } \ ++ if (!last) \ ++ cpumask_complement(chk, mask) ++ ++static void sched_init_topology_cpumask(void) ++{ ++ int cpu; ++ cpumask_t *chk, *topo; ++ ++ for_each_online_cpu(cpu) { ++ /* take chance to reset time slice for idle tasks */ ++ cpu_rq(cpu)->idle->time_slice = sched_timeslice_ns; ++ ++ chk = per_cpu(sched_cpu_affinity_masks, cpu) + 1; ++ topo = per_cpu(sched_cpu_topo_masks, cpu) + 1; ++ ++ cpumask_complement(chk, cpumask_of(cpu)); ++#ifdef CONFIG_SCHED_SMT ++ TOPOLOGY_CPUMASK(smt, topology_sibling_cpumask(cpu), false); ++#endif ++ per_cpu(sd_llc_id, cpu) = cpumask_first(cpu_coregroup_mask(cpu)); ++ per_cpu(sched_cpu_llc_mask, cpu) = topo; ++ TOPOLOGY_CPUMASK(coregroup, cpu_coregroup_mask(cpu), false); ++ ++ TOPOLOGY_CPUMASK(core, topology_core_cpumask(cpu), false); ++ ++ TOPOLOGY_CPUMASK(others, cpu_online_mask, true); ++ ++ per_cpu(sched_cpu_affinity_end_mask, cpu) = chk; ++ printk(KERN_INFO "sched: cpu#%02d llc_id = %d, llc_mask idx = %d\n", ++ cpu, per_cpu(sd_llc_id, cpu), ++ (int) (per_cpu(sched_cpu_llc_mask, cpu) - ++ per_cpu(sched_cpu_topo_masks, cpu))); ++ } ++} ++#endif ++ ++void __init sched_init_smp(void) ++{ ++ /* Move init over to a non-isolated CPU */ ++ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0) ++ BUG(); ++ ++ sched_init_topology_cpumask(); ++ ++ sched_smp_initialized = true; ++} ++#else ++void __init sched_init_smp(void) ++{ ++ cpu_rq(0)->idle->time_slice = sched_timeslice_ns; ++} ++#endif /* CONFIG_SMP */ ++ ++int in_sched_functions(unsigned long addr) ++{ ++ return in_lock_functions(addr) || ++ (addr >= (unsigned long)__sched_text_start ++ && addr < (unsigned long)__sched_text_end); ++} ++ ++#ifdef CONFIG_CGROUP_SCHED ++/* task group related information */ ++struct task_group { ++ struct cgroup_subsys_state css; ++ ++ struct rcu_head rcu; ++ struct list_head list; ++ ++ struct task_group *parent; ++ struct list_head siblings; ++ struct list_head children; ++#ifdef CONFIG_FAIR_GROUP_SCHED ++ unsigned long shares; ++#endif ++}; ++ ++/* ++ * Default task group. ++ * Every task in system belongs to this group at bootup. ++ */ ++struct task_group root_task_group; ++LIST_HEAD(task_groups); ++ ++/* Cacheline aligned slab cache for task_group */ ++static struct kmem_cache *task_group_cache __read_mostly; ++#endif /* CONFIG_CGROUP_SCHED */ ++ ++void __init sched_init(void) ++{ ++ int i; ++ struct rq *rq; ++ ++ printk(KERN_INFO ALT_SCHED_VERSION_MSG); ++ ++ wait_bit_init(); ++ ++#ifdef CONFIG_SMP ++ for (i = 0; i < SCHED_BITS; i++) ++ cpumask_copy(&sched_rq_watermark[i], cpu_present_mask); ++#endif ++ ++#ifdef CONFIG_CGROUP_SCHED ++ task_group_cache = KMEM_CACHE(task_group, 0); ++ ++ list_add(&root_task_group.list, &task_groups); ++ INIT_LIST_HEAD(&root_task_group.children); ++ INIT_LIST_HEAD(&root_task_group.siblings); ++#endif /* CONFIG_CGROUP_SCHED */ ++ for_each_possible_cpu(i) { ++ rq = cpu_rq(i); ++ ++ sched_queue_init(rq); ++ rq->watermark = IDLE_WM; ++ rq->skip = NULL; ++ ++ raw_spin_lock_init(&rq->lock); ++ rq->nr_running = rq->nr_uninterruptible = 0; ++ rq->calc_load_active = 0; ++ rq->calc_load_update = jiffies + LOAD_FREQ; ++#ifdef CONFIG_SMP ++ rq->online = false; ++ rq->cpu = i; ++ ++#ifdef CONFIG_SCHED_SMT ++ rq->active_balance = 0; ++#endif ++ ++#ifdef CONFIG_NO_HZ_COMMON ++ INIT_CSD(&rq->nohz_csd, nohz_csd_func, rq); ++#endif ++ rq->balance_callback = NULL; ++#ifdef CONFIG_HOTPLUG_CPU ++ rcuwait_init(&rq->hotplug_wait); ++#endif ++#endif /* CONFIG_SMP */ ++ rq->nr_switches = 0; ++ ++ hrtick_rq_init(rq); ++ atomic_set(&rq->nr_iowait, 0); ++ } ++#ifdef CONFIG_SMP ++ /* Set rq->online for cpu 0 */ ++ cpu_rq(0)->online = true; ++#endif ++ /* ++ * The boot idle thread does lazy MMU switching as well: ++ */ ++ mmgrab(&init_mm); ++ enter_lazy_tlb(&init_mm, current); ++ ++ /* ++ * Make us the idle thread. Technically, schedule() should not be ++ * called from this thread, however somewhere below it might be, ++ * but because we are the idle thread, we just pick up running again ++ * when this runqueue becomes "idle". ++ */ ++ init_idle(current, smp_processor_id()); ++ ++ calc_load_update = jiffies + LOAD_FREQ; ++ ++#ifdef CONFIG_SMP ++ idle_thread_set_boot_cpu(); ++ ++ sched_init_topology_cpumask_early(); ++#endif /* SMP */ ++ ++ init_schedstats(); ++ ++ psi_init(); ++} ++ ++#ifdef CONFIG_DEBUG_ATOMIC_SLEEP ++static inline int preempt_count_equals(int preempt_offset) ++{ ++ int nested = preempt_count() + rcu_preempt_depth(); ++ ++ return (nested == preempt_offset); ++} ++ ++void __might_sleep(const char *file, int line, int preempt_offset) ++{ ++ /* ++ * Blocking primitives will set (and therefore destroy) current->state, ++ * since we will exit with TASK_RUNNING make sure we enter with it, ++ * otherwise we will destroy state. ++ */ ++ WARN_ONCE(current->state != TASK_RUNNING && current->task_state_change, ++ "do not call blocking ops when !TASK_RUNNING; " ++ "state=%lx set at [<%p>] %pS\n", ++ current->state, ++ (void *)current->task_state_change, ++ (void *)current->task_state_change); ++ ++ ___might_sleep(file, line, preempt_offset); ++} ++EXPORT_SYMBOL(__might_sleep); ++ ++void ___might_sleep(const char *file, int line, int preempt_offset) ++{ ++ /* Ratelimiting timestamp: */ ++ static unsigned long prev_jiffy; ++ ++ unsigned long preempt_disable_ip; ++ ++ /* WARN_ON_ONCE() by default, no rate limit required: */ ++ rcu_sleep_check(); ++ ++ if ((preempt_count_equals(preempt_offset) && !irqs_disabled() && ++ !is_idle_task(current) && !current->non_block_count) || ++ system_state == SYSTEM_BOOTING || system_state > SYSTEM_RUNNING || ++ oops_in_progress) ++ return; ++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) ++ return; ++ prev_jiffy = jiffies; ++ ++ /* Save this before calling printk(), since that will clobber it: */ ++ preempt_disable_ip = get_preempt_disable_ip(current); ++ ++ printk(KERN_ERR ++ "BUG: sleeping function called from invalid context at %s:%d\n", ++ file, line); ++ printk(KERN_ERR ++ "in_atomic(): %d, irqs_disabled(): %d, non_block: %d, pid: %d, name: %s\n", ++ in_atomic(), irqs_disabled(), current->non_block_count, ++ current->pid, current->comm); ++ ++ if (task_stack_end_corrupted(current)) ++ printk(KERN_EMERG "Thread overran stack, or stack corrupted\n"); ++ ++ debug_show_held_locks(current); ++ if (irqs_disabled()) ++ print_irqtrace_events(current); ++#ifdef CONFIG_DEBUG_PREEMPT ++ if (!preempt_count_equals(preempt_offset)) { ++ pr_err("Preemption disabled at:"); ++ print_ip_sym(KERN_ERR, preempt_disable_ip); ++ } ++#endif ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++EXPORT_SYMBOL(___might_sleep); ++ ++void __cant_sleep(const char *file, int line, int preempt_offset) ++{ ++ static unsigned long prev_jiffy; ++ ++ if (irqs_disabled()) ++ return; ++ ++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) ++ return; ++ ++ if (preempt_count() > preempt_offset) ++ return; ++ ++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) ++ return; ++ prev_jiffy = jiffies; ++ ++ printk(KERN_ERR "BUG: assuming atomic context at %s:%d\n", file, line); ++ printk(KERN_ERR "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", ++ in_atomic(), irqs_disabled(), ++ current->pid, current->comm); ++ ++ debug_show_held_locks(current); ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++EXPORT_SYMBOL_GPL(__cant_sleep); ++ ++#ifdef CONFIG_SMP ++void __cant_migrate(const char *file, int line) ++{ ++ static unsigned long prev_jiffy; ++ ++ if (irqs_disabled()) ++ return; ++ ++ if (is_migration_disabled(current)) ++ return; ++ ++ if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) ++ return; ++ ++ if (preempt_count() > 0) ++ return; ++ ++ if (current->migration_flags & MDF_FORCE_ENABLED) ++ return; ++ ++ if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) ++ return; ++ prev_jiffy = jiffies; ++ ++ pr_err("BUG: assuming non migratable context at %s:%d\n", file, line); ++ pr_err("in_atomic(): %d, irqs_disabled(): %d, migration_disabled() %u pid: %d, name: %s\n", ++ in_atomic(), irqs_disabled(), is_migration_disabled(current), ++ current->pid, current->comm); ++ ++ debug_show_held_locks(current); ++ dump_stack(); ++ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); ++} ++EXPORT_SYMBOL_GPL(__cant_migrate); ++#endif ++#endif ++ ++#ifdef CONFIG_MAGIC_SYSRQ ++void normalize_rt_tasks(void) ++{ ++ struct task_struct *g, *p; ++ struct sched_attr attr = { ++ .sched_policy = SCHED_NORMAL, ++ }; ++ ++ read_lock(&tasklist_lock); ++ for_each_process_thread(g, p) { ++ /* ++ * Only normalize user tasks: ++ */ ++ if (p->flags & PF_KTHREAD) ++ continue; ++ ++ if (!rt_task(p)) { ++ /* ++ * Renice negative nice level userspace ++ * tasks back to 0: ++ */ ++ if (task_nice(p) < 0) ++ set_user_nice(p, 0); ++ continue; ++ } ++ ++ __sched_setscheduler(p, &attr, false, false); ++ } ++ read_unlock(&tasklist_lock); ++} ++#endif /* CONFIG_MAGIC_SYSRQ */ ++ ++#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) ++/* ++ * These functions are only useful for the IA64 MCA handling, or kdb. ++ * ++ * They can only be called when the whole system has been ++ * stopped - every CPU needs to be quiescent, and no scheduling ++ * activity can take place. Using them for anything else would ++ * be a serious bug, and as a result, they aren't even visible ++ * under any other configuration. ++ */ ++ ++/** ++ * curr_task - return the current task for a given CPU. ++ * @cpu: the processor in question. ++ * ++ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! ++ * ++ * Return: The current task for @cpu. ++ */ ++struct task_struct *curr_task(int cpu) ++{ ++ return cpu_curr(cpu); ++} ++ ++#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ ++ ++#ifdef CONFIG_IA64 ++/** ++ * ia64_set_curr_task - set the current task for a given CPU. ++ * @cpu: the processor in question. ++ * @p: the task pointer to set. ++ * ++ * Description: This function must only be used when non-maskable interrupts ++ * are serviced on a separate stack. It allows the architecture to switch the ++ * notion of the current task on a CPU in a non-blocking manner. This function ++ * must be called with all CPU's synchronised, and interrupts disabled, the ++ * and caller must save the original value of the current task (see ++ * curr_task() above) and restore that value before reenabling interrupts and ++ * re-starting the system. ++ * ++ * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! ++ */ ++void ia64_set_curr_task(int cpu, struct task_struct *p) ++{ ++ cpu_curr(cpu) = p; ++} ++ ++#endif ++ ++#ifdef CONFIG_CGROUP_SCHED ++static void sched_free_group(struct task_group *tg) ++{ ++ kmem_cache_free(task_group_cache, tg); ++} ++ ++/* allocate runqueue etc for a new task group */ ++struct task_group *sched_create_group(struct task_group *parent) ++{ ++ struct task_group *tg; ++ ++ tg = kmem_cache_alloc(task_group_cache, GFP_KERNEL | __GFP_ZERO); ++ if (!tg) ++ return ERR_PTR(-ENOMEM); ++ ++ return tg; ++} ++ ++void sched_online_group(struct task_group *tg, struct task_group *parent) ++{ ++} ++ ++/* rcu callback to free various structures associated with a task group */ ++static void sched_free_group_rcu(struct rcu_head *rhp) ++{ ++ /* Now it should be safe to free those cfs_rqs */ ++ sched_free_group(container_of(rhp, struct task_group, rcu)); ++} ++ ++void sched_destroy_group(struct task_group *tg) ++{ ++ /* Wait for possible concurrent references to cfs_rqs complete */ ++ call_rcu(&tg->rcu, sched_free_group_rcu); ++} ++ ++void sched_offline_group(struct task_group *tg) ++{ ++} ++ ++static inline struct task_group *css_tg(struct cgroup_subsys_state *css) ++{ ++ return css ? container_of(css, struct task_group, css) : NULL; ++} ++ ++static struct cgroup_subsys_state * ++cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) ++{ ++ struct task_group *parent = css_tg(parent_css); ++ struct task_group *tg; ++ ++ if (!parent) { ++ /* This is early initialization for the top cgroup */ ++ return &root_task_group.css; ++ } ++ ++ tg = sched_create_group(parent); ++ if (IS_ERR(tg)) ++ return ERR_PTR(-ENOMEM); ++ return &tg->css; ++} ++ ++/* Expose task group only after completing cgroup initialization */ ++static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) ++{ ++ struct task_group *tg = css_tg(css); ++ struct task_group *parent = css_tg(css->parent); ++ ++ if (parent) ++ sched_online_group(tg, parent); ++ return 0; ++} ++ ++static void cpu_cgroup_css_released(struct cgroup_subsys_state *css) ++{ ++ struct task_group *tg = css_tg(css); ++ ++ sched_offline_group(tg); ++} ++ ++static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) ++{ ++ struct task_group *tg = css_tg(css); ++ ++ /* ++ * Relies on the RCU grace period between css_released() and this. ++ */ ++ sched_free_group(tg); ++} ++ ++static void cpu_cgroup_fork(struct task_struct *task) ++{ ++} ++ ++static int cpu_cgroup_can_attach(struct cgroup_taskset *tset) ++{ ++ return 0; ++} ++ ++static void cpu_cgroup_attach(struct cgroup_taskset *tset) ++{ ++} ++ ++#ifdef CONFIG_FAIR_GROUP_SCHED ++static DEFINE_MUTEX(shares_mutex); ++ ++int sched_group_set_shares(struct task_group *tg, unsigned long shares) ++{ ++ /* ++ * We can't change the weight of the root cgroup. ++ */ ++ if (&root_task_group == tg) ++ return -EINVAL; ++ ++ shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); ++ ++ mutex_lock(&shares_mutex); ++ if (tg->shares == shares) ++ goto done; ++ ++ tg->shares = shares; ++done: ++ mutex_unlock(&shares_mutex); ++ return 0; ++} ++ ++static int cpu_shares_write_u64(struct cgroup_subsys_state *css, ++ struct cftype *cftype, u64 shareval) ++{ ++ if (shareval > scale_load_down(ULONG_MAX)) ++ shareval = MAX_SHARES; ++ return sched_group_set_shares(css_tg(css), scale_load(shareval)); ++} ++ ++static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, ++ struct cftype *cft) ++{ ++ struct task_group *tg = css_tg(css); ++ ++ return (u64) scale_load_down(tg->shares); ++} ++#endif ++ ++static struct cftype cpu_legacy_files[] = { ++#ifdef CONFIG_FAIR_GROUP_SCHED ++ { ++ .name = "shares", ++ .read_u64 = cpu_shares_read_u64, ++ .write_u64 = cpu_shares_write_u64, ++ }, ++#endif ++ { } /* Terminate */ ++}; ++ ++ ++static struct cftype cpu_files[] = { ++ { } /* terminate */ ++}; ++ ++static int cpu_extra_stat_show(struct seq_file *sf, ++ struct cgroup_subsys_state *css) ++{ ++ return 0; ++} ++ ++struct cgroup_subsys cpu_cgrp_subsys = { ++ .css_alloc = cpu_cgroup_css_alloc, ++ .css_online = cpu_cgroup_css_online, ++ .css_released = cpu_cgroup_css_released, ++ .css_free = cpu_cgroup_css_free, ++ .css_extra_stat_show = cpu_extra_stat_show, ++ .fork = cpu_cgroup_fork, ++ .can_attach = cpu_cgroup_can_attach, ++ .attach = cpu_cgroup_attach, ++ .legacy_cftypes = cpu_files, ++ .legacy_cftypes = cpu_legacy_files, ++ .dfl_cftypes = cpu_files, ++ .early_init = true, ++ .threaded = true, ++}; ++#endif /* CONFIG_CGROUP_SCHED */ ++ ++#undef CREATE_TRACE_POINTS +diff --git a/kernel/sched/alt_debug.c b/kernel/sched/alt_debug.c +new file mode 100644 +index 000000000000..1212a031700e +--- /dev/null ++++ b/kernel/sched/alt_debug.c +@@ -0,0 +1,31 @@ ++/* ++ * kernel/sched/alt_debug.c ++ * ++ * Print the alt scheduler debugging details ++ * ++ * Author: Alfred Chen ++ * Date : 2020 ++ */ ++#include "sched.h" ++ ++/* ++ * This allows printing both to /proc/sched_debug and ++ * to the console ++ */ ++#define SEQ_printf(m, x...) \ ++ do { \ ++ if (m) \ ++ seq_printf(m, x); \ ++ else \ ++ pr_cont(x); \ ++ } while (0) ++ ++void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, ++ struct seq_file *m) ++{ ++ SEQ_printf(m, "%s (%d, #threads: %d)\n", p->comm, task_pid_nr_ns(p, ns), ++ get_nr_threads(p)); ++} ++ ++void proc_sched_set_task(struct task_struct *p) ++{} +diff --git a/kernel/sched/alt_sched.h b/kernel/sched/alt_sched.h +new file mode 100644 +index 000000000000..2a6a0530fbb7 +--- /dev/null ++++ b/kernel/sched/alt_sched.h +@@ -0,0 +1,686 @@ ++#ifndef ALT_SCHED_H ++#define ALT_SCHED_H ++ ++#include <linux/sched.h> ++ ++#include <linux/sched/clock.h> ++#include <linux/sched/cpufreq.h> ++#include <linux/sched/cputime.h> ++#include <linux/sched/debug.h> ++#include <linux/sched/init.h> ++#include <linux/sched/isolation.h> ++#include <linux/sched/loadavg.h> ++#include <linux/sched/mm.h> ++#include <linux/sched/nohz.h> ++#include <linux/sched/signal.h> ++#include <linux/sched/stat.h> ++#include <linux/sched/sysctl.h> ++#include <linux/sched/task.h> ++#include <linux/sched/topology.h> ++#include <linux/sched/wake_q.h> ++ ++#include <uapi/linux/sched/types.h> ++ ++#include <linux/cgroup.h> ++#include <linux/cpufreq.h> ++#include <linux/cpuidle.h> ++#include <linux/cpuset.h> ++#include <linux/ctype.h> ++#include <linux/debugfs.h> ++#include <linux/kthread.h> ++#include <linux/livepatch.h> ++#include <linux/membarrier.h> ++#include <linux/proc_fs.h> ++#include <linux/psi.h> ++#include <linux/slab.h> ++#include <linux/stop_machine.h> ++#include <linux/suspend.h> ++#include <linux/swait.h> ++#include <linux/syscalls.h> ++#include <linux/tsacct_kern.h> ++ ++#include <asm/tlb.h> ++ ++#ifdef CONFIG_PARAVIRT ++# include <asm/paravirt.h> ++#endif ++ ++#include "cpupri.h" ++ ++#include <trace/events/sched.h> ++ ++#ifdef CONFIG_SCHED_BMQ ++#include "bmq.h" ++#endif ++#ifdef CONFIG_SCHED_PDS ++#include "pds.h" ++#endif ++ ++#ifdef CONFIG_SCHED_DEBUG ++# define SCHED_WARN_ON(x) WARN_ONCE(x, #x) ++#else ++# define SCHED_WARN_ON(x) ({ (void)(x), 0; }) ++#endif ++ ++/* ++ * Increase resolution of nice-level calculations for 64-bit architectures. ++ * The extra resolution improves shares distribution and load balancing of ++ * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup ++ * hierarchies, especially on larger systems. This is not a user-visible change ++ * and does not change the user-interface for setting shares/weights. ++ * ++ * We increase resolution only if we have enough bits to allow this increased ++ * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit ++ * are pretty high and the returns do not justify the increased costs. ++ * ++ * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to ++ * increase coverage and consistency always enable it on 64-bit platforms. ++ */ ++#ifdef CONFIG_64BIT ++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) ++# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) ++# define scale_load_down(w) \ ++({ \ ++ unsigned long __w = (w); \ ++ if (__w) \ ++ __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ ++ __w; \ ++}) ++#else ++# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) ++# define scale_load(w) (w) ++# define scale_load_down(w) (w) ++#endif ++ ++#ifdef CONFIG_FAIR_GROUP_SCHED ++#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD ++ ++/* ++ * A weight of 0 or 1 can cause arithmetics problems. ++ * A weight of a cfs_rq is the sum of weights of which entities ++ * are queued on this cfs_rq, so a weight of a entity should not be ++ * too large, so as the shares value of a task group. ++ * (The default weight is 1024 - so there's no practical ++ * limitation from this.) ++ */ ++#define MIN_SHARES (1UL << 1) ++#define MAX_SHARES (1UL << 18) ++#endif ++ ++/* task_struct::on_rq states: */ ++#define TASK_ON_RQ_QUEUED 1 ++#define TASK_ON_RQ_MIGRATING 2 ++ ++static inline int task_on_rq_queued(struct task_struct *p) ++{ ++ return p->on_rq == TASK_ON_RQ_QUEUED; ++} ++ ++static inline int task_on_rq_migrating(struct task_struct *p) ++{ ++ return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; ++} ++ ++/* ++ * wake flags ++ */ ++#define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ ++#define WF_FORK 0x02 /* child wakeup after fork */ ++#define WF_MIGRATED 0x04 /* internal use, task got migrated */ ++#define WF_ON_CPU 0x08 /* Wakee is on_rq */ ++ ++/* ++ * This is the main, per-CPU runqueue data structure. ++ * This data should only be modified by the local cpu. ++ */ ++struct rq { ++ /* runqueue lock: */ ++ raw_spinlock_t lock; ++ ++ struct task_struct __rcu *curr; ++ struct task_struct *idle, *stop, *skip; ++ struct mm_struct *prev_mm; ++ ++#ifdef CONFIG_SCHED_BMQ ++ struct bmq queue; ++#endif ++#ifdef CONFIG_SCHED_PDS ++ struct skiplist_node sl_header; ++#endif ++ unsigned long watermark; ++ ++ /* switch count */ ++ u64 nr_switches; ++ ++ atomic_t nr_iowait; ++ ++#ifdef CONFIG_MEMBARRIER ++ int membarrier_state; ++#endif ++ ++#ifdef CONFIG_SMP ++ int cpu; /* cpu of this runqueue */ ++ bool online; ++ ++ unsigned int ttwu_pending; ++ unsigned char nohz_idle_balance; ++ unsigned char idle_balance; ++ ++#ifdef CONFIG_HAVE_SCHED_AVG_IRQ ++ struct sched_avg avg_irq; ++#endif ++ ++#ifdef CONFIG_SCHED_SMT ++ int active_balance; ++ struct cpu_stop_work active_balance_work; ++#endif ++ struct callback_head *balance_callback; ++ unsigned char balance_push; ++#ifdef CONFIG_HOTPLUG_CPU ++ struct rcuwait hotplug_wait; ++#endif ++ unsigned int nr_pinned; ++#endif /* CONFIG_SMP */ ++#ifdef CONFIG_IRQ_TIME_ACCOUNTING ++ u64 prev_irq_time; ++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ ++#ifdef CONFIG_PARAVIRT ++ u64 prev_steal_time; ++#endif /* CONFIG_PARAVIRT */ ++#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING ++ u64 prev_steal_time_rq; ++#endif /* CONFIG_PARAVIRT_TIME_ACCOUNTING */ ++ ++ /* calc_load related fields */ ++ unsigned long calc_load_update; ++ long calc_load_active; ++ ++ u64 clock, last_tick; ++ u64 last_ts_switch; ++ u64 clock_task; ++ ++ unsigned int nr_running; ++ unsigned long nr_uninterruptible; ++ ++#ifdef CONFIG_SCHED_HRTICK ++#ifdef CONFIG_SMP ++ call_single_data_t hrtick_csd; ++#endif ++ struct hrtimer hrtick_timer; ++ ktime_t hrtick_time; ++#endif ++ ++#ifdef CONFIG_SCHEDSTATS ++ ++ /* latency stats */ ++ struct sched_info rq_sched_info; ++ unsigned long long rq_cpu_time; ++ /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ ++ ++ /* sys_sched_yield() stats */ ++ unsigned int yld_count; ++ ++ /* schedule() stats */ ++ unsigned int sched_switch; ++ unsigned int sched_count; ++ unsigned int sched_goidle; ++ ++ /* try_to_wake_up() stats */ ++ unsigned int ttwu_count; ++ unsigned int ttwu_local; ++#endif /* CONFIG_SCHEDSTATS */ ++ ++#ifdef CONFIG_CPU_IDLE ++ /* Must be inspected within a rcu lock section */ ++ struct cpuidle_state *idle_state; ++#endif ++ ++#ifdef CONFIG_NO_HZ_COMMON ++#ifdef CONFIG_SMP ++ call_single_data_t nohz_csd; ++#endif ++ atomic_t nohz_flags; ++#endif /* CONFIG_NO_HZ_COMMON */ ++}; ++ ++extern unsigned long calc_load_update; ++extern atomic_long_t calc_load_tasks; ++ ++extern void calc_global_load_tick(struct rq *this_rq); ++extern long calc_load_fold_active(struct rq *this_rq, long adjust); ++ ++DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); ++#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) ++#define this_rq() this_cpu_ptr(&runqueues) ++#define task_rq(p) cpu_rq(task_cpu(p)) ++#define cpu_curr(cpu) (cpu_rq(cpu)->curr) ++#define raw_rq() raw_cpu_ptr(&runqueues) ++ ++#ifdef CONFIG_SMP ++#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) ++void register_sched_domain_sysctl(void); ++void unregister_sched_domain_sysctl(void); ++#else ++static inline void register_sched_domain_sysctl(void) ++{ ++} ++static inline void unregister_sched_domain_sysctl(void) ++{ ++} ++#endif ++ ++extern bool sched_smp_initialized; ++ ++enum { ++ ITSELF_LEVEL_SPACE_HOLDER, ++#ifdef CONFIG_SCHED_SMT ++ SMT_LEVEL_SPACE_HOLDER, ++#endif ++ COREGROUP_LEVEL_SPACE_HOLDER, ++ CORE_LEVEL_SPACE_HOLDER, ++ OTHER_LEVEL_SPACE_HOLDER, ++ NR_CPU_AFFINITY_LEVELS ++}; ++ ++DECLARE_PER_CPU(cpumask_t [NR_CPU_AFFINITY_LEVELS], sched_cpu_topo_masks); ++DECLARE_PER_CPU(cpumask_t *, sched_cpu_llc_mask); ++ ++static inline int __best_mask_cpu(int cpu, const cpumask_t *cpumask, ++ const cpumask_t *mask) ++{ ++#if NR_CPUS <= 64 ++ unsigned long t; ++ ++ while ((t = cpumask->bits[0] & mask->bits[0]) == 0UL) ++ mask++; ++ ++ return __ffs(t); ++#else ++ while ((cpu = cpumask_any_and(cpumask, mask)) >= nr_cpu_ids) ++ mask++; ++ return cpu; ++#endif ++} ++ ++static inline int best_mask_cpu(int cpu, const cpumask_t *mask) ++{ ++#if NR_CPUS <= 64 ++ unsigned long llc_match; ++ cpumask_t *chk = per_cpu(sched_cpu_llc_mask, cpu); ++ ++ if ((llc_match = mask->bits[0] & chk->bits[0])) { ++ unsigned long match; ++ ++ chk = per_cpu(sched_cpu_topo_masks, cpu); ++ if (mask->bits[0] & chk->bits[0]) ++ return cpu; ++ ++#ifdef CONFIG_SCHED_SMT ++ chk++; ++ if ((match = mask->bits[0] & chk->bits[0])) ++ return __ffs(match); ++#endif ++ ++ return __ffs(llc_match); ++ } ++ ++ return __best_mask_cpu(cpu, mask, chk + 1); ++#else ++ cpumask_t llc_match; ++ cpumask_t *chk = per_cpu(sched_cpu_llc_mask, cpu); ++ ++ if (cpumask_and(&llc_match, mask, chk)) { ++ cpumask_t tmp; ++ ++ chk = per_cpu(sched_cpu_topo_masks, cpu); ++ if (cpumask_test_cpu(cpu, mask)) ++ return cpu; ++ ++#ifdef CONFIG_SCHED_SMT ++ chk++; ++ if (cpumask_and(&tmp, mask, chk)) ++ return cpumask_any(&tmp); ++#endif ++ ++ return cpumask_any(&llc_match); ++ } ++ ++ return __best_mask_cpu(cpu, mask, chk + 1); ++#endif ++} ++ ++extern void flush_smp_call_function_from_idle(void); ++ ++#else /* !CONFIG_SMP */ ++static inline void flush_smp_call_function_from_idle(void) { } ++#endif ++ ++#ifndef arch_scale_freq_tick ++static __always_inline ++void arch_scale_freq_tick(void) ++{ ++} ++#endif ++ ++#ifndef arch_scale_freq_capacity ++static __always_inline ++unsigned long arch_scale_freq_capacity(int cpu) ++{ ++ return SCHED_CAPACITY_SCALE; ++} ++#endif ++ ++static inline u64 __rq_clock_broken(struct rq *rq) ++{ ++ return READ_ONCE(rq->clock); ++} ++ ++static inline u64 rq_clock(struct rq *rq) ++{ ++ /* ++ * Relax lockdep_assert_held() checking as in VRQ, call to ++ * sched_info_xxxx() may not held rq->lock ++ * lockdep_assert_held(&rq->lock); ++ */ ++ return rq->clock; ++} ++ ++static inline u64 rq_clock_task(struct rq *rq) ++{ ++ /* ++ * Relax lockdep_assert_held() checking as in VRQ, call to ++ * sched_info_xxxx() may not held rq->lock ++ * lockdep_assert_held(&rq->lock); ++ */ ++ return rq->clock_task; ++} ++ ++/* ++ * {de,en}queue flags: ++ * ++ * DEQUEUE_SLEEP - task is no longer runnable ++ * ENQUEUE_WAKEUP - task just became runnable ++ * ++ */ ++ ++#define DEQUEUE_SLEEP 0x01 ++ ++#define ENQUEUE_WAKEUP 0x01 ++ ++ ++/* ++ * Below are scheduler API which using in other kernel code ++ * It use the dummy rq_flags ++ * ToDo : BMQ need to support these APIs for compatibility with mainline ++ * scheduler code. ++ */ ++struct rq_flags { ++ unsigned long flags; ++}; ++ ++struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(rq->lock); ++ ++struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) ++ __acquires(p->pi_lock) ++ __acquires(rq->lock); ++ ++static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock(&rq->lock); ++} ++ ++static inline void ++task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) ++ __releases(rq->lock) ++ __releases(p->pi_lock) ++{ ++ raw_spin_unlock(&rq->lock); ++ raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); ++} ++ ++static inline void ++rq_lock(struct rq *rq, struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ raw_spin_lock(&rq->lock); ++} ++ ++static inline void ++rq_unlock_irq(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock_irq(&rq->lock); ++} ++ ++static inline void ++rq_unlock(struct rq *rq, struct rq_flags *rf) ++ __releases(rq->lock) ++{ ++ raw_spin_unlock(&rq->lock); ++} ++ ++static inline struct rq * ++this_rq_lock_irq(struct rq_flags *rf) ++ __acquires(rq->lock) ++{ ++ struct rq *rq; ++ ++ local_irq_disable(); ++ rq = this_rq(); ++ raw_spin_lock(&rq->lock); ++ ++ return rq; ++} ++ ++static inline int task_current(struct rq *rq, struct task_struct *p) ++{ ++ return rq->curr == p; ++} ++ ++static inline bool task_running(struct task_struct *p) ++{ ++ return p->on_cpu; ++} ++ ++extern int task_running_nice(struct task_struct *p); ++ ++extern struct static_key_false sched_schedstats; ++ ++#ifdef CONFIG_CPU_IDLE ++static inline void idle_set_state(struct rq *rq, ++ struct cpuidle_state *idle_state) ++{ ++ rq->idle_state = idle_state; ++} ++ ++static inline struct cpuidle_state *idle_get_state(struct rq *rq) ++{ ++ WARN_ON(!rcu_read_lock_held()); ++ return rq->idle_state; ++} ++#else ++static inline void idle_set_state(struct rq *rq, ++ struct cpuidle_state *idle_state) ++{ ++} ++ ++static inline struct cpuidle_state *idle_get_state(struct rq *rq) ++{ ++ return NULL; ++} ++#endif ++ ++static inline int cpu_of(const struct rq *rq) ++{ ++#ifdef CONFIG_SMP ++ return rq->cpu; ++#else ++ return 0; ++#endif ++} ++ ++#include "stats.h" ++ ++#ifdef CONFIG_NO_HZ_COMMON ++#define NOHZ_BALANCE_KICK_BIT 0 ++#define NOHZ_STATS_KICK_BIT 1 ++ ++#define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) ++#define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) ++ ++#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK) ++ ++#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) ++ ++/* TODO: needed? ++extern void nohz_balance_exit_idle(struct rq *rq); ++#else ++static inline void nohz_balance_exit_idle(struct rq *rq) { } ++*/ ++#endif ++ ++#ifdef CONFIG_IRQ_TIME_ACCOUNTING ++struct irqtime { ++ u64 total; ++ u64 tick_delta; ++ u64 irq_start_time; ++ struct u64_stats_sync sync; ++}; ++ ++DECLARE_PER_CPU(struct irqtime, cpu_irqtime); ++ ++/* ++ * Returns the irqtime minus the softirq time computed by ksoftirqd. ++ * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime ++ * and never move forward. ++ */ ++static inline u64 irq_time_read(int cpu) ++{ ++ struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); ++ unsigned int seq; ++ u64 total; ++ ++ do { ++ seq = __u64_stats_fetch_begin(&irqtime->sync); ++ total = irqtime->total; ++ } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); ++ ++ return total; ++} ++#endif /* CONFIG_IRQ_TIME_ACCOUNTING */ ++ ++#ifdef CONFIG_CPU_FREQ ++DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); ++ ++/** ++ * cpufreq_update_util - Take a note about CPU utilization changes. ++ * @rq: Runqueue to carry out the update for. ++ * @flags: Update reason flags. ++ * ++ * This function is called by the scheduler on the CPU whose utilization is ++ * being updated. ++ * ++ * It can only be called from RCU-sched read-side critical sections. ++ * ++ * The way cpufreq is currently arranged requires it to evaluate the CPU ++ * performance state (frequency/voltage) on a regular basis to prevent it from ++ * being stuck in a completely inadequate performance level for too long. ++ * That is not guaranteed to happen if the updates are only triggered from CFS ++ * and DL, though, because they may not be coming in if only RT tasks are ++ * active all the time (or there are RT tasks only). ++ * ++ * As a workaround for that issue, this function is called periodically by the ++ * RT sched class to trigger extra cpufreq updates to prevent it from stalling, ++ * but that really is a band-aid. Going forward it should be replaced with ++ * solutions targeted more specifically at RT tasks. ++ */ ++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) ++{ ++ struct update_util_data *data; ++ ++ data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, ++ cpu_of(rq))); ++ if (data) ++ data->func(data, rq_clock(rq), flags); ++} ++#else ++static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} ++#endif /* CONFIG_CPU_FREQ */ ++ ++#ifdef CONFIG_NO_HZ_FULL ++extern int __init sched_tick_offload_init(void); ++#else ++static inline int sched_tick_offload_init(void) { return 0; } ++#endif ++ ++#ifdef arch_scale_freq_capacity ++#ifndef arch_scale_freq_invariant ++#define arch_scale_freq_invariant() (true) ++#endif ++#else /* arch_scale_freq_capacity */ ++#define arch_scale_freq_invariant() (false) ++#endif ++ ++extern void schedule_idle(void); ++ ++#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) ++ ++/* ++ * !! For sched_setattr_nocheck() (kernel) only !! ++ * ++ * This is actually gross. :( ++ * ++ * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE ++ * tasks, but still be able to sleep. We need this on platforms that cannot ++ * atomically change clock frequency. Remove once fast switching will be ++ * available on such platforms. ++ * ++ * SUGOV stands for SchedUtil GOVernor. ++ */ ++#define SCHED_FLAG_SUGOV 0x10000000 ++ ++#ifdef CONFIG_MEMBARRIER ++/* ++ * The scheduler provides memory barriers required by membarrier between: ++ * - prior user-space memory accesses and store to rq->membarrier_state, ++ * - store to rq->membarrier_state and following user-space memory accesses. ++ * In the same way it provides those guarantees around store to rq->curr. ++ */ ++static inline void membarrier_switch_mm(struct rq *rq, ++ struct mm_struct *prev_mm, ++ struct mm_struct *next_mm) ++{ ++ int membarrier_state; ++ ++ if (prev_mm == next_mm) ++ return; ++ ++ membarrier_state = atomic_read(&next_mm->membarrier_state); ++ if (READ_ONCE(rq->membarrier_state) == membarrier_state) ++ return; ++ ++ WRITE_ONCE(rq->membarrier_state, membarrier_state); ++} ++#else ++static inline void membarrier_switch_mm(struct rq *rq, ++ struct mm_struct *prev_mm, ++ struct mm_struct *next_mm) ++{ ++} ++#endif ++ ++#ifdef CONFIG_NUMA ++extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); ++#else ++static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) ++{ ++ return nr_cpu_ids; ++} ++#endif ++ ++void swake_up_all_locked(struct swait_queue_head *q); ++void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); ++ ++#endif /* ALT_SCHED_H */ +diff --git a/kernel/sched/bmq.h b/kernel/sched/bmq.h +new file mode 100644 +index 000000000000..aba3c98759f8 +--- /dev/null ++++ b/kernel/sched/bmq.h +@@ -0,0 +1,14 @@ ++#ifndef BMQ_H ++#define BMQ_H ++ ++/* bits: ++ * RT(0-99), (Low prio adj range, nice width, high prio adj range) / 2, cpu idle task */ ++#define SCHED_BITS (MAX_RT_PRIO + NICE_WIDTH / 2 + MAX_PRIORITY_ADJ + 1) ++#define IDLE_TASK_SCHED_PRIO (SCHED_BITS - 1) ++ ++struct bmq { ++ DECLARE_BITMAP(bitmap, SCHED_BITS); ++ struct list_head heads[SCHED_BITS]; ++}; ++ ++#endif +diff --git a/kernel/sched/bmq_imp.h b/kernel/sched/bmq_imp.h +new file mode 100644 +index 000000000000..7c71f1141d00 +--- /dev/null ++++ b/kernel/sched/bmq_imp.h +@@ -0,0 +1,203 @@ ++#define ALT_SCHED_VERSION_MSG "sched/bmq: BMQ CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n" ++ ++/* ++ * BMQ only routines ++ */ ++#define rq_switch_time(rq) ((rq)->clock - (rq)->last_ts_switch) ++#define boost_threshold(p) (sched_timeslice_ns >>\ ++ (15 - MAX_PRIORITY_ADJ - (p)->boost_prio)) ++ ++static inline void boost_task(struct task_struct *p) ++{ ++ int limit; ++ ++ switch (p->policy) { ++ case SCHED_NORMAL: ++ limit = -MAX_PRIORITY_ADJ; ++ break; ++ case SCHED_BATCH: ++ case SCHED_IDLE: ++ limit = 0; ++ break; ++ default: ++ return; ++ } ++ ++ if (p->boost_prio > limit) ++ p->boost_prio--; ++} ++ ++static inline void deboost_task(struct task_struct *p) ++{ ++ if (p->boost_prio < MAX_PRIORITY_ADJ) ++ p->boost_prio++; ++} ++ ++/* ++ * Common interfaces ++ */ ++static inline int normal_prio(struct task_struct *p) ++{ ++ if (task_has_rt_policy(p)) ++ return MAX_RT_PRIO - 1 - p->rt_priority; ++ ++ return p->static_prio + MAX_PRIORITY_ADJ; ++} ++ ++static inline int task_sched_prio(struct task_struct *p, struct rq *rq) ++{ ++ return (p->prio < MAX_RT_PRIO)? p->prio : MAX_RT_PRIO / 2 + (p->prio + p->boost_prio) / 2; ++} ++ ++static inline void requeue_task(struct task_struct *p, struct rq *rq); ++ ++static inline void time_slice_expired(struct task_struct *p, struct rq *rq) ++{ ++ p->time_slice = sched_timeslice_ns; ++ ++ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) { ++ if (SCHED_RR != p->policy) ++ deboost_task(p); ++ requeue_task(p, rq); ++ } ++} ++ ++inline int task_running_nice(struct task_struct *p) ++{ ++ return (p->prio + p->boost_prio > DEFAULT_PRIO + MAX_PRIORITY_ADJ); ++} ++ ++static inline void update_task_priodl(struct task_struct *p) {} ++ ++static inline unsigned long sched_queue_watermark(struct rq *rq) ++{ ++ return find_first_bit(rq->queue.bitmap, SCHED_BITS); ++} ++ ++static inline void sched_queue_init(struct rq *rq) ++{ ++ struct bmq *q = &rq->queue; ++ int i; ++ ++ bitmap_zero(q->bitmap, SCHED_BITS); ++ for(i = 0; i < SCHED_BITS; i++) ++ INIT_LIST_HEAD(&q->heads[i]); ++} ++ ++static inline void sched_queue_init_idle(struct rq *rq, struct task_struct *idle) ++{ ++ struct bmq *q = &rq->queue; ++ ++ idle->bmq_idx = IDLE_TASK_SCHED_PRIO; ++ INIT_LIST_HEAD(&q->heads[idle->bmq_idx]); ++ list_add(&idle->bmq_node, &q->heads[idle->bmq_idx]); ++ set_bit(idle->bmq_idx, q->bitmap); ++} ++ ++/* ++ * This routine used in bmq scheduler only which assume the idle task in the bmq ++ */ ++static inline struct task_struct *sched_rq_first_task(struct rq *rq) ++{ ++ unsigned long idx = find_first_bit(rq->queue.bitmap, SCHED_BITS); ++ const struct list_head *head = &rq->queue.heads[idx]; ++ ++ return list_first_entry(head, struct task_struct, bmq_node); ++} ++ ++static inline struct task_struct * ++sched_rq_next_task(struct task_struct *p, struct rq *rq) ++{ ++ unsigned long idx = p->bmq_idx; ++ struct list_head *head = &rq->queue.heads[idx]; ++ ++ if (list_is_last(&p->bmq_node, head)) { ++ idx = find_next_bit(rq->queue.bitmap, SCHED_BITS, idx + 1); ++ head = &rq->queue.heads[idx]; ++ ++ return list_first_entry(head, struct task_struct, bmq_node); ++ } ++ ++ return list_next_entry(p, bmq_node); ++} ++ ++#define __SCHED_DEQUEUE_TASK(p, rq, flags, func) \ ++ psi_dequeue(p, flags & DEQUEUE_SLEEP); \ ++ sched_info_dequeued(rq, p); \ ++ \ ++ list_del(&p->bmq_node); \ ++ if (list_empty(&rq->queue.heads[p->bmq_idx])) { \ ++ clear_bit(p->bmq_idx, rq->queue.bitmap);\ ++ func; \ ++ } ++ ++#define __SCHED_ENQUEUE_TASK(p, rq, flags) \ ++ sched_info_queued(rq, p); \ ++ psi_enqueue(p, flags); \ ++ \ ++ p->bmq_idx = task_sched_prio(p, rq); \ ++ list_add_tail(&p->bmq_node, &rq->queue.heads[p->bmq_idx]); \ ++ set_bit(p->bmq_idx, rq->queue.bitmap) ++ ++#define __SCHED_REQUEUE_TASK(p, rq, func) \ ++{ \ ++ int idx = task_sched_prio(p, rq); \ ++\ ++ list_del(&p->bmq_node); \ ++ list_add_tail(&p->bmq_node, &rq->queue.heads[idx]); \ ++ if (idx != p->bmq_idx) { \ ++ if (list_empty(&rq->queue.heads[p->bmq_idx])) \ ++ clear_bit(p->bmq_idx, rq->queue.bitmap); \ ++ p->bmq_idx = idx; \ ++ set_bit(p->bmq_idx, rq->queue.bitmap); \ ++ func; \ ++ } \ ++} ++ ++static inline bool sched_task_need_requeue(struct task_struct *p, struct rq *rq) ++{ ++ return (task_sched_prio(p, rq) != p->bmq_idx); ++} ++ ++static void sched_task_fork(struct task_struct *p, struct rq *rq) ++{ ++ p->boost_prio = (p->boost_prio < 0) ? ++ p->boost_prio + MAX_PRIORITY_ADJ : MAX_PRIORITY_ADJ; ++} ++ ++/** ++ * task_prio - return the priority value of a given task. ++ * @p: the task in question. ++ * ++ * Return: The priority value as seen by users in /proc. ++ * ++ * sched policy return value kernel prio user prio/nice/boost ++ * ++ * normal, batch, idle [0 ... 53] [100 ... 139] 0/[-20 ... 19]/[-7 ... 7] ++ * fifo, rr [-1 ... -100] [99 ... 0] [0 ... 99] ++ */ ++int task_prio(const struct task_struct *p) ++{ ++ if (p->prio < MAX_RT_PRIO) ++ return (p->prio - MAX_RT_PRIO); ++ return (p->prio - MAX_RT_PRIO + p->boost_prio); ++} ++ ++static void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) ++{ ++ p->boost_prio = MAX_PRIORITY_ADJ; ++} ++ ++#ifdef CONFIG_SMP ++static void sched_task_ttwu(struct task_struct *p) ++{ ++ if(this_rq()->clock_task - p->last_ran > sched_timeslice_ns) ++ boost_task(p); ++} ++#endif ++ ++static void sched_task_deactivate(struct task_struct *p, struct rq *rq) ++{ ++ if (rq_switch_time(rq) < boost_threshold(p)) ++ boost_task(p); ++} +diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c +index 50cbad89f7fa..41946f19468b 100644 +--- a/kernel/sched/cpufreq_schedutil.c ++++ b/kernel/sched/cpufreq_schedutil.c +@@ -57,6 +57,13 @@ struct sugov_cpu { + unsigned long bw_dl; + unsigned long max; + ++#ifdef CONFIG_SCHED_ALT ++ /* For genenal cpu load util */ ++ s32 load_history; ++ u64 load_block; ++ u64 load_stamp; ++#endif ++ + /* The field below is for single-CPU policies only: */ + #ifdef CONFIG_NO_HZ_COMMON + unsigned long saved_idle_calls; +@@ -171,6 +178,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, + return cpufreq_driver_resolve_freq(policy, freq); + } + ++#ifndef CONFIG_SCHED_ALT + static void sugov_get_util(struct sugov_cpu *sg_cpu) + { + struct rq *rq = cpu_rq(sg_cpu->cpu); +@@ -182,6 +190,55 @@ static void sugov_get_util(struct sugov_cpu *sg_cpu) + FREQUENCY_UTIL, NULL); + } + ++#else /* CONFIG_SCHED_ALT */ ++ ++#define SG_CPU_LOAD_HISTORY_BITS (sizeof(s32) * 8ULL) ++#define SG_CPU_UTIL_SHIFT (8) ++#define SG_CPU_LOAD_HISTORY_SHIFT (SG_CPU_LOAD_HISTORY_BITS - 1 - SG_CPU_UTIL_SHIFT) ++#define SG_CPU_LOAD_HISTORY_TO_UTIL(l) (((l) >> SG_CPU_LOAD_HISTORY_SHIFT) & 0xff) ++ ++#define LOAD_BLOCK(t) ((t) >> 17) ++#define LOAD_HALF_BLOCK(t) ((t) >> 16) ++#define BLOCK_MASK(t) ((t) & ((0x01 << 18) - 1)) ++#define LOAD_BLOCK_BIT(b) (1UL << (SG_CPU_LOAD_HISTORY_BITS - 1 - (b))) ++#define CURRENT_LOAD_BIT LOAD_BLOCK_BIT(0) ++ ++static void sugov_get_util(struct sugov_cpu *sg_cpu) ++{ ++ unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu); ++ ++ sg_cpu->max = max; ++ sg_cpu->bw_dl = 0; ++ sg_cpu->util = SG_CPU_LOAD_HISTORY_TO_UTIL(sg_cpu->load_history) * ++ (max >> SG_CPU_UTIL_SHIFT); ++} ++ ++static inline void sugov_cpu_load_update(struct sugov_cpu *sg_cpu, u64 time) ++{ ++ u64 delta = min(LOAD_BLOCK(time) - LOAD_BLOCK(sg_cpu->load_stamp), ++ SG_CPU_LOAD_HISTORY_BITS - 1); ++ u64 prev = !!(sg_cpu->load_history & CURRENT_LOAD_BIT); ++ u64 curr = !!cpu_rq(sg_cpu->cpu)->nr_running; ++ ++ if (delta) { ++ sg_cpu->load_history = sg_cpu->load_history >> delta; ++ ++ if (delta <= SG_CPU_UTIL_SHIFT) { ++ sg_cpu->load_block += (~BLOCK_MASK(sg_cpu->load_stamp)) * prev; ++ if (!!LOAD_HALF_BLOCK(sg_cpu->load_block) ^ curr) ++ sg_cpu->load_history ^= LOAD_BLOCK_BIT(delta); ++ } ++ ++ sg_cpu->load_block = BLOCK_MASK(time) * prev; ++ } else { ++ sg_cpu->load_block += (time - sg_cpu->load_stamp) * prev; ++ } ++ if (prev ^ curr) ++ sg_cpu->load_history ^= CURRENT_LOAD_BIT; ++ sg_cpu->load_stamp = time; ++} ++#endif /* CONFIG_SCHED_ALT */ ++ + /** + * sugov_iowait_reset() - Reset the IO boost status of a CPU. + * @sg_cpu: the sugov data for the CPU to boost +@@ -322,13 +379,19 @@ static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; } + */ + static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu) + { ++#ifndef CONFIG_SCHED_ALT + if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl) + sg_cpu->sg_policy->limits_changed = true; ++#endif + } + + static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, + u64 time, unsigned int flags) + { ++#ifdef CONFIG_SCHED_ALT ++ sugov_cpu_load_update(sg_cpu, time); ++#endif /* CONFIG_SCHED_ALT */ ++ + sugov_iowait_boost(sg_cpu, time, flags); + sg_cpu->last_update = time; + +@@ -446,6 +509,10 @@ sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags) + + raw_spin_lock(&sg_policy->update_lock); + ++#ifdef CONFIG_SCHED_ALT ++ sugov_cpu_load_update(sg_cpu, time); ++#endif /* CONFIG_SCHED_ALT */ ++ + sugov_iowait_boost(sg_cpu, time, flags); + sg_cpu->last_update = time; + +@@ -603,6 +670,7 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy) + } + + ret = sched_setattr_nocheck(thread, &attr); ++ + if (ret) { + kthread_stop(thread); + pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__); +@@ -837,7 +905,9 @@ cpufreq_governor_init(schedutil_gov); + #ifdef CONFIG_ENERGY_MODEL + static void rebuild_sd_workfn(struct work_struct *work) + { ++#ifndef CONFIG_SCHED_ALT + rebuild_sched_domains_energy(); ++#endif /* CONFIG_SCHED_ALT */ + } + static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); + +diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c +index 5f611658eeab..631276f56ba0 100644 +--- a/kernel/sched/cputime.c ++++ b/kernel/sched/cputime.c +@@ -123,7 +123,7 @@ void account_user_time(struct task_struct *p, u64 cputime) + p->utime += cputime; + account_group_user_time(p, cputime); + +- index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER; ++ index = task_running_nice(p) ? CPUTIME_NICE : CPUTIME_USER; + + /* Add user time to cpustat. */ + task_group_account_field(p, index, cputime); +@@ -147,7 +147,7 @@ void account_guest_time(struct task_struct *p, u64 cputime) + p->gtime += cputime; + + /* Add guest time to cpustat. */ +- if (task_nice(p) > 0) { ++ if (task_running_nice(p)) { + cpustat[CPUTIME_NICE] += cputime; + cpustat[CPUTIME_GUEST_NICE] += cputime; + } else { +@@ -270,7 +270,7 @@ static inline u64 account_other_time(u64 max) + #ifdef CONFIG_64BIT + static inline u64 read_sum_exec_runtime(struct task_struct *t) + { +- return t->se.sum_exec_runtime; ++ return tsk_seruntime(t); + } + #else + static u64 read_sum_exec_runtime(struct task_struct *t) +@@ -280,7 +280,7 @@ static u64 read_sum_exec_runtime(struct task_struct *t) + struct rq *rq; + + rq = task_rq_lock(t, &rf); +- ns = t->se.sum_exec_runtime; ++ ns = tsk_seruntime(t); + task_rq_unlock(rq, t, &rf); + + return ns; +@@ -612,7 +612,7 @@ void cputime_adjust(struct task_cputime *curr, struct prev_cputime *prev, + void task_cputime_adjusted(struct task_struct *p, u64 *ut, u64 *st) + { + struct task_cputime cputime = { +- .sum_exec_runtime = p->se.sum_exec_runtime, ++ .sum_exec_runtime = tsk_seruntime(p), + }; + + task_cputime(p, &cputime.utime, &cputime.stime); +diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c +index 7199e6f23789..bbdd227da3a4 100644 +--- a/kernel/sched/idle.c ++++ b/kernel/sched/idle.c +@@ -397,6 +397,7 @@ void cpu_startup_entry(enum cpuhp_state state) + do_idle(); + } + ++#ifndef CONFIG_SCHED_ALT + /* + * idle-task scheduling class. + */ +@@ -510,3 +511,4 @@ DEFINE_SCHED_CLASS(idle) = { + .switched_to = switched_to_idle, + .update_curr = update_curr_idle, + }; ++#endif +diff --git a/kernel/sched/pds.h b/kernel/sched/pds.h +new file mode 100644 +index 000000000000..623908cf4380 +--- /dev/null ++++ b/kernel/sched/pds.h +@@ -0,0 +1,9 @@ ++#ifndef PDS_H ++#define PDS_H ++ ++/* bits: ++ * RT(0-99), (Low prio adj range, nice width, high prio adj range) / 2, cpu idle task */ ++#define SCHED_BITS (MAX_RT_PRIO + NICE_WIDTH / 2 + 1) ++#define IDLE_TASK_SCHED_PRIO (SCHED_BITS - 1) ++ ++#endif +diff --git a/kernel/sched/pds_imp.h b/kernel/sched/pds_imp.h +new file mode 100644 +index 000000000000..335ce3a8e3ec +--- /dev/null ++++ b/kernel/sched/pds_imp.h +@@ -0,0 +1,279 @@ ++#define ALT_SCHED_VERSION_MSG "sched/pds: PDS CPU Scheduler "ALT_SCHED_VERSION" by Alfred Chen.\n" ++ ++static const u64 user_prio2deadline[NICE_WIDTH] = { ++/* -20 */ 4194304, 4613734, 5075107, 5582617, 6140878, ++/* -15 */ 6754965, 7430461, 8173507, 8990857, 9889942, ++/* -10 */ 10878936, 11966829, 13163511, 14479862, 15927848, ++/* -5 */ 17520632, 19272695, 21199964, 23319960, 25651956, ++/* 0 */ 28217151, 31038866, 34142752, 37557027, 41312729, ++/* 5 */ 45444001, 49988401, 54987241, 60485965, 66534561, ++/* 10 */ 73188017, 80506818, 88557499, 97413248, 107154572, ++/* 15 */ 117870029, 129657031, 142622734, 156885007, 172573507 ++}; ++ ++static const unsigned char dl_level_map[] = { ++/* 0 4 8 12 */ ++ 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 18, ++/* 16 20 24 28 */ ++ 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 17, 17, 17, 17, 17, ++/* 32 36 40 44 */ ++ 17, 17, 17, 17, 16, 16, 16, 16, 16, 16, 16, 16, 15, 15, 15, 15, ++/* 48 52 56 60 */ ++ 15, 15, 15, 14, 14, 14, 14, 14, 14, 13, 13, 13, 13, 12, 12, 12, ++/* 64 68 72 76 */ ++ 12, 11, 11, 11, 10, 10, 10, 9, 9, 8, 7, 6, 5, 4, 3, 2, ++/* 80 84 88 92 */ ++ 1, 0 ++}; ++ ++/* DEFAULT_SCHED_PRIO: ++ * dl_level_map[(user_prio2deadline[39] - user_prio2deadline[0]) >> 21] = ++ * dl_level_map[68] = ++ * 10 ++ */ ++#define DEFAULT_SCHED_PRIO (MAX_RT_PRIO + 10) ++ ++static inline int normal_prio(struct task_struct *p) ++{ ++ if (task_has_rt_policy(p)) ++ return MAX_RT_PRIO - 1 - p->rt_priority; ++ ++ return MAX_RT_PRIO; ++} ++ ++static inline int ++task_sched_prio(const struct task_struct *p, const struct rq *rq) ++{ ++ size_t delta; ++ ++ if (p == rq->idle) ++ return IDLE_TASK_SCHED_PRIO; ++ ++ if (p->prio < MAX_RT_PRIO) ++ return p->prio; ++ ++ delta = (rq->clock + user_prio2deadline[39] - p->deadline) >> 21; ++ delta = min((size_t)delta, ARRAY_SIZE(dl_level_map) - 1); ++ ++ return MAX_RT_PRIO + dl_level_map[delta]; ++} ++ ++int task_running_nice(struct task_struct *p) ++{ ++ return task_sched_prio(p, task_rq(p)) > DEFAULT_SCHED_PRIO; ++} ++ ++static inline void update_task_priodl(struct task_struct *p) ++{ ++ p->priodl = (((u64) (p->prio))<<56) | ((p->deadline)>>8); ++} ++ ++static inline void requeue_task(struct task_struct *p, struct rq *rq); ++ ++static inline void time_slice_expired(struct task_struct *p, struct rq *rq) ++{ ++ /*printk(KERN_INFO "sched: time_slice_expired(%d) - %px\n", cpu_of(rq), p);*/ ++ p->time_slice = sched_timeslice_ns; ++ ++ if (p->prio >= MAX_RT_PRIO) ++ p->deadline = rq->clock + ++ user_prio2deadline[p->static_prio - MAX_RT_PRIO]; ++ update_task_priodl(p); ++ ++ if (SCHED_FIFO != p->policy && task_on_rq_queued(p)) ++ requeue_task(p, rq); ++} ++ ++/* ++ * pds_skiplist_task_search -- search function used in PDS run queue skip list ++ * node insert operation. ++ * @it: iterator pointer to the node in the skip list ++ * @node: pointer to the skiplist_node to be inserted ++ * ++ * Returns true if key of @it is less or equal to key value of @node, otherwise ++ * false. ++ */ ++static inline bool ++pds_skiplist_task_search(struct skiplist_node *it, struct skiplist_node *node) ++{ ++ return (skiplist_entry(it, struct task_struct, sl_node)->priodl <= ++ skiplist_entry(node, struct task_struct, sl_node)->priodl); ++} ++ ++/* ++ * Define the skip list insert function for PDS ++ */ ++DEFINE_SKIPLIST_INSERT_FUNC(pds_skiplist_insert, pds_skiplist_task_search); ++ ++/* ++ * Init the queue structure in rq ++ */ ++static inline void sched_queue_init(struct rq *rq) ++{ ++ INIT_SKIPLIST_NODE(&rq->sl_header); ++} ++ ++/* ++ * Init idle task and put into queue structure of rq ++ * IMPORTANT: may be called multiple times for a single cpu ++ */ ++static inline void sched_queue_init_idle(struct rq *rq, struct task_struct *idle) ++{ ++ /*printk(KERN_INFO "sched: init(%d) - %px\n", cpu_of(rq), idle);*/ ++ int default_prio = idle->prio; ++ ++ idle->prio = MAX_PRIO; ++ idle->deadline = 0ULL; ++ update_task_priodl(idle); ++ ++ INIT_SKIPLIST_NODE(&rq->sl_header); ++ ++ idle->sl_node.level = idle->sl_level; ++ pds_skiplist_insert(&rq->sl_header, &idle->sl_node); ++ ++ idle->prio = default_prio; ++} ++ ++/* ++ * This routine assume that the idle task always in queue ++ */ ++static inline struct task_struct *sched_rq_first_task(struct rq *rq) ++{ ++ struct skiplist_node *node = rq->sl_header.next[0]; ++ ++ BUG_ON(node == &rq->sl_header); ++ return skiplist_entry(node, struct task_struct, sl_node); ++} ++ ++static inline struct task_struct * ++sched_rq_next_task(struct task_struct *p, struct rq *rq) ++{ ++ struct skiplist_node *next = p->sl_node.next[0]; ++ ++ BUG_ON(next == &rq->sl_header); ++ return skiplist_entry(next, struct task_struct, sl_node); ++} ++ ++static inline unsigned long sched_queue_watermark(struct rq *rq) ++{ ++ return task_sched_prio(sched_rq_first_task(rq), rq); ++} ++ ++#define __SCHED_DEQUEUE_TASK(p, rq, flags, func) \ ++ psi_dequeue(p, flags & DEQUEUE_SLEEP); \ ++ sched_info_dequeued(rq, p); \ ++ \ ++ if (skiplist_del_init(&rq->sl_header, &p->sl_node)) { \ ++ func; \ ++ } ++ ++#define __SCHED_ENQUEUE_TASK(p, rq, flags) \ ++ sched_info_queued(rq, p); \ ++ psi_enqueue(p, flags); \ ++ \ ++ p->sl_node.level = p->sl_level; \ ++ pds_skiplist_insert(&rq->sl_header, &p->sl_node) ++ ++/* ++ * Requeue a task @p to @rq ++ */ ++#define __SCHED_REQUEUE_TASK(p, rq, func) \ ++{\ ++ bool b_first = skiplist_del_init(&rq->sl_header, &p->sl_node); \ ++\ ++ p->sl_node.level = p->sl_level; \ ++ if (pds_skiplist_insert(&rq->sl_header, &p->sl_node) || b_first) { \ ++ func; \ ++ } \ ++} ++ ++static inline bool sched_task_need_requeue(struct task_struct *p, struct rq *rq) ++{ ++ struct skiplist_node *node; ++ ++ node = p->sl_node.prev[0]; ++ if (node != &rq->sl_header && ++ skiplist_entry(node, struct task_struct, sl_node)->priodl > p->priodl) ++ return true; ++ ++ node = p->sl_node.next[0]; ++ if (node != &rq->sl_header && ++ skiplist_entry(node, struct task_struct, sl_node)->priodl < p->priodl) ++ return true; ++ ++ return false; ++} ++ ++/* ++ * pds_skiplist_random_level -- Returns a pseudo-random level number for skip ++ * list node which is used in PDS run queue. ++ * ++ * __ffs() is used to satisfy p = 0.5 between each levels, and there should be ++ * platform instruction(known as ctz/clz) for acceleration. ++ * ++ * The skiplist level for a task is populated when task is created and doesn't ++ * change in task's life time. When task is being inserted into run queue, this ++ * skiplist level is set to task's sl_node->level, the skiplist insert function ++ * may change it based on current level of the skip lsit. ++ */ ++static inline int pds_skiplist_random_level(const struct task_struct *p) ++{ ++ /* ++ * 1. Some architectures don't have better than microsecond resolution ++ * so mask out ~microseconds as a factor of the random seed for skiplist ++ * insertion. ++ * 2. Use address of task structure pointer as another factor of the ++ * random seed for task burst forking scenario. ++ */ ++ unsigned long randseed = (task_rq(p)->clock ^ (unsigned long)p) >> 10; ++ ++ randseed &= __GENMASK(NUM_SKIPLIST_LEVEL - 1, 0); ++ if (randseed) ++ return __ffs(randseed); ++ ++ return (NUM_SKIPLIST_LEVEL - 1); ++} ++ ++static void sched_task_fork(struct task_struct *p, struct rq *rq) ++{ ++ p->sl_level = pds_skiplist_random_level(p); ++ if (p->prio >= MAX_RT_PRIO) ++ p->deadline = rq->clock + ++ user_prio2deadline[p->static_prio - MAX_RT_PRIO]; ++ update_task_priodl(p); ++} ++ ++/** ++ * task_prio - return the priority value of a given task. ++ * @p: the task in question. ++ * ++ * Return: The priority value as seen by users in /proc. ++ * ++ * sched policy return value kernel prio user prio/nice ++ * ++ * normal, batch, idle [0 ... 39] 100 0/[-20 ... 19] ++ * fifo, rr [-1 ... -100] [99 ... 0] [0 ... 99] ++ */ ++int task_prio(const struct task_struct *p) ++{ ++ int ret; ++ ++ if (p->prio < MAX_RT_PRIO) ++ return (p->prio - MAX_RT_PRIO); ++ ++ preempt_disable(); ++ ret = task_sched_prio(p, this_rq()) - MAX_RT_PRIO; ++ preempt_enable(); ++ ++ return ret; ++} ++ ++static void do_sched_yield_type_1(struct task_struct *p, struct rq *rq) ++{ ++ time_slice_expired(p, rq); ++} ++ ++#ifdef CONFIG_SMP ++static void sched_task_ttwu(struct task_struct *p) {} ++#endif ++static void sched_task_deactivate(struct task_struct *p, struct rq *rq) {} +diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c +index 2c613e1cff3a..0103b2a7201d 100644 +--- a/kernel/sched/pelt.c ++++ b/kernel/sched/pelt.c +@@ -270,6 +270,7 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load) + WRITE_ONCE(sa->util_avg, sa->util_sum / divider); + } + ++#ifndef CONFIG_SCHED_ALT + /* + * sched_entity: + * +@@ -387,8 +388,9 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running) + + return 0; + } ++#endif + +-#ifdef CONFIG_SCHED_THERMAL_PRESSURE ++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) + /* + * thermal: + * +diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h +index 795e43e02afc..856163dac896 100644 +--- a/kernel/sched/pelt.h ++++ b/kernel/sched/pelt.h +@@ -1,13 +1,15 @@ + #ifdef CONFIG_SMP + #include "sched-pelt.h" + ++#ifndef CONFIG_SCHED_ALT + int __update_load_avg_blocked_se(u64 now, struct sched_entity *se); + int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se); + int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq); + int update_rt_rq_load_avg(u64 now, struct rq *rq, int running); + int update_dl_rq_load_avg(u64 now, struct rq *rq, int running); ++#endif + +-#ifdef CONFIG_SCHED_THERMAL_PRESSURE ++#if defined(CONFIG_SCHED_THERMAL_PRESSURE) && !defined(CONFIG_SCHED_ALT) + int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity); + + static inline u64 thermal_load_avg(struct rq *rq) +@@ -42,6 +44,7 @@ static inline u32 get_pelt_divider(struct sched_avg *avg) + return LOAD_AVG_MAX - 1024 + avg->period_contrib; + } + ++#ifndef CONFIG_SCHED_ALT + /* + * When a task is dequeued, its estimated utilization should not be update if + * its util_avg has not been updated at least once. +@@ -162,9 +165,11 @@ static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) + return rq_clock_pelt(rq_of(cfs_rq)); + } + #endif ++#endif /* CONFIG_SCHED_ALT */ + + #else + ++#ifndef CONFIG_SCHED_ALT + static inline int + update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) + { +@@ -182,6 +187,7 @@ update_dl_rq_load_avg(u64 now, struct rq *rq, int running) + { + return 0; + } ++#endif + + static inline int + update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity) +diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h +index 10a1522b1e30..1a74a266340b 100644 +--- a/kernel/sched/sched.h ++++ b/kernel/sched/sched.h +@@ -2,6 +2,10 @@ + /* + * Scheduler internal types and methods: + */ ++#ifdef CONFIG_SCHED_ALT ++#include "alt_sched.h" ++#else ++ + #include <linux/sched.h> + + #include <linux/sched/autogroup.h> +@@ -2720,3 +2724,9 @@ static inline bool is_per_cpu_kthread(struct task_struct *p) + + void swake_up_all_locked(struct swait_queue_head *q); + void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); ++ ++static inline int task_running_nice(struct task_struct *p) ++{ ++ return (task_nice(p) > 0); ++} ++#endif /* !CONFIG_SCHED_ALT */ +diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c +index 750fb3c67eed..108422ebc7bf 100644 +--- a/kernel/sched/stats.c ++++ b/kernel/sched/stats.c +@@ -22,8 +22,10 @@ static int show_schedstat(struct seq_file *seq, void *v) + } else { + struct rq *rq; + #ifdef CONFIG_SMP ++#ifndef CONFIG_SCHED_ALT + struct sched_domain *sd; + int dcount = 0; ++#endif + #endif + cpu = (unsigned long)(v - 2); + rq = cpu_rq(cpu); +@@ -40,6 +42,7 @@ static int show_schedstat(struct seq_file *seq, void *v) + seq_printf(seq, "\n"); + + #ifdef CONFIG_SMP ++#ifndef CONFIG_SCHED_ALT + /* domain-specific stats */ + rcu_read_lock(); + for_each_domain(cpu, sd) { +@@ -68,6 +71,7 @@ static int show_schedstat(struct seq_file *seq, void *v) + sd->ttwu_move_balance); + } + rcu_read_unlock(); ++#endif + #endif + } + return 0; +diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c +index 09d35044bd88..2c146b042b51 100644 +--- a/kernel/sched/topology.c ++++ b/kernel/sched/topology.c +@@ -4,6 +4,7 @@ + */ + #include "sched.h" + ++#ifndef CONFIG_SCHED_ALT + DEFINE_MUTEX(sched_domains_mutex); + + /* Protected by sched_domains_mutex: */ +@@ -1241,8 +1242,10 @@ static void init_sched_groups_capacity(int cpu, struct sched_domain *sd) + */ + + static int default_relax_domain_level = -1; ++#endif /* CONFIG_SCHED_ALT */ + int sched_domain_level_max; + ++#ifndef CONFIG_SCHED_ALT + static int __init setup_relax_domain_level(char *str) + { + if (kstrtoint(str, 0, &default_relax_domain_level)) +@@ -1472,6 +1475,7 @@ sd_init(struct sched_domain_topology_level *tl, + + return sd; + } ++#endif /* CONFIG_SCHED_ALT */ + + /* + * Topology list, bottom-up. +@@ -1501,6 +1505,7 @@ void set_sched_topology(struct sched_domain_topology_level *tl) + sched_domain_topology = tl; + } + ++#ifndef CONFIG_SCHED_ALT + #ifdef CONFIG_NUMA + + static const struct cpumask *sd_numa_mask(int cpu) +@@ -2371,3 +2376,17 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], + partition_sched_domains_locked(ndoms_new, doms_new, dattr_new); + mutex_unlock(&sched_domains_mutex); + } ++#else /* CONFIG_SCHED_ALT */ ++void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], ++ struct sched_domain_attr *dattr_new) ++{} ++ ++#ifdef CONFIG_NUMA ++int __read_mostly node_reclaim_distance = RECLAIM_DISTANCE; ++ ++int sched_numa_find_closest(const struct cpumask *cpus, int cpu) ++{ ++ return best_mask_cpu(cpu, cpus); ++} ++#endif /* CONFIG_NUMA */ ++#endif +diff --git a/kernel/sysctl.c b/kernel/sysctl.c +index 62fbd09b5dc1..19f9a6185db3 100644 +--- a/kernel/sysctl.c ++++ b/kernel/sysctl.c +@@ -120,6 +120,10 @@ static unsigned long long_max = LONG_MAX; + static int one_hundred = 100; + static int two_hundred = 200; + static int one_thousand = 1000; ++#ifdef CONFIG_SCHED_ALT ++static int __maybe_unused zero = 0; ++extern int sched_yield_type; ++#endif + #ifdef CONFIG_PRINTK + static int ten_thousand = 10000; + #endif +@@ -184,7 +188,7 @@ static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT; + int sysctl_legacy_va_layout; + #endif + +-#ifdef CONFIG_SCHED_DEBUG ++#if defined(CONFIG_SCHED_DEBUG) && !defined(CONFIG_SCHED_ALT) + static int min_sched_granularity_ns = 100000; /* 100 usecs */ + static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */ + static int min_wakeup_granularity_ns; /* 0 usecs */ +@@ -1652,6 +1656,24 @@ int proc_do_static_key(struct ctl_table *table, int write, + } + + static struct ctl_table kern_table[] = { ++#ifdef CONFIG_SCHED_ALT ++/* In ALT, only supported "sched_schedstats" */ ++#ifdef CONFIG_SCHED_DEBUG ++#ifdef CONFIG_SMP ++#ifdef CONFIG_SCHEDSTATS ++ { ++ .procname = "sched_schedstats", ++ .data = NULL, ++ .maxlen = sizeof(unsigned int), ++ .mode = 0644, ++ .proc_handler = sysctl_schedstats, ++ .extra1 = SYSCTL_ZERO, ++ .extra2 = SYSCTL_ONE, ++ }, ++#endif /* CONFIG_SCHEDSTATS */ ++#endif /* CONFIG_SMP */ ++#endif /* CONFIG_SCHED_DEBUG */ ++#else /* !CONFIG_SCHED_ALT */ + { + .procname = "sched_child_runs_first", + .data = &sysctl_sched_child_runs_first, +@@ -1854,6 +1876,7 @@ static struct ctl_table kern_table[] = { + .extra2 = SYSCTL_ONE, + }, + #endif ++#endif /* !CONFIG_SCHED_ALT */ + #ifdef CONFIG_PROVE_LOCKING + { + .procname = "prove_locking", +@@ -2430,6 +2453,17 @@ static struct ctl_table kern_table[] = { + .proc_handler = proc_dointvec, + }, + #endif ++#ifdef CONFIG_SCHED_ALT ++ { ++ .procname = "yield_type", ++ .data = &sched_yield_type, ++ .maxlen = sizeof (int), ++ .mode = 0644, ++ .proc_handler = &proc_dointvec_minmax, ++ .extra1 = &zero, ++ .extra2 = &two, ++ }, ++#endif + #if defined(CONFIG_S390) && defined(CONFIG_SMP) + { + .procname = "spin_retry", +diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c +index 5c9d968187ae..fe47db46303c 100644 +--- a/kernel/time/hrtimer.c ++++ b/kernel/time/hrtimer.c +@@ -1940,8 +1940,10 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, + int ret = 0; + u64 slack; + ++#ifndef CONFIG_SCHED_ALT + slack = current->timer_slack_ns; + if (dl_task(current) || rt_task(current)) ++#endif + slack = 0; + + hrtimer_init_sleeper_on_stack(&t, clockid, mode); +diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c +index 9abe15255bc4..691db8192ddb 100644 +--- a/kernel/time/posix-cpu-timers.c ++++ b/kernel/time/posix-cpu-timers.c +@@ -216,7 +216,7 @@ static void task_sample_cputime(struct task_struct *p, u64 *samples) + u64 stime, utime; + + task_cputime(p, &utime, &stime); +- store_samples(samples, stime, utime, p->se.sum_exec_runtime); ++ store_samples(samples, stime, utime, tsk_seruntime(p)); + } + + static void proc_sample_cputime_atomic(struct task_cputime_atomic *at, +@@ -801,6 +801,7 @@ static void collect_posix_cputimers(struct posix_cputimers *pct, u64 *samples, + } + } + ++#ifndef CONFIG_SCHED_ALT + static inline void check_dl_overrun(struct task_struct *tsk) + { + if (tsk->dl.dl_overrun) { +@@ -808,6 +809,7 @@ static inline void check_dl_overrun(struct task_struct *tsk) + __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); + } + } ++#endif + + static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard) + { +@@ -835,8 +837,10 @@ static void check_thread_timers(struct task_struct *tsk, + u64 samples[CPUCLOCK_MAX]; + unsigned long soft; + ++#ifndef CONFIG_SCHED_ALT + if (dl_task(tsk)) + check_dl_overrun(tsk); ++#endif + + if (expiry_cache_is_inactive(pct)) + return; +@@ -850,7 +854,7 @@ static void check_thread_timers(struct task_struct *tsk, + soft = task_rlimit(tsk, RLIMIT_RTTIME); + if (soft != RLIM_INFINITY) { + /* Task RT timeout is accounted in jiffies. RTTIME is usec */ +- unsigned long rttime = tsk->rt.timeout * (USEC_PER_SEC / HZ); ++ unsigned long rttime = tsk_rttimeout(tsk) * (USEC_PER_SEC / HZ); + unsigned long hard = task_rlimit_max(tsk, RLIMIT_RTTIME); + + /* At the hard limit, send SIGKILL. No further action. */ +@@ -1086,8 +1090,10 @@ static inline bool fastpath_timer_check(struct task_struct *tsk) + return true; + } + ++#ifndef CONFIG_SCHED_ALT + if (dl_task(tsk) && tsk->dl.dl_overrun) + return true; ++#endif + + return false; + } +diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c +index 73ef12092250..24bf8ef1249a 100644 +--- a/kernel/trace/trace_selftest.c ++++ b/kernel/trace/trace_selftest.c +@@ -1052,10 +1052,15 @@ static int trace_wakeup_test_thread(void *data) + { + /* Make this a -deadline thread */ + static const struct sched_attr attr = { ++#ifdef CONFIG_SCHED_ALT ++ /* No deadline on BMQ/PDS, use RR */ ++ .sched_policy = SCHED_RR, ++#else + .sched_policy = SCHED_DEADLINE, + .sched_runtime = 100000ULL, + .sched_deadline = 10000000ULL, + .sched_period = 10000000ULL ++#endif + }; + struct wakeup_test_data *x = data; + |