diff options
| -rw-r--r-- | CREDITS | 3 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 4 | ||||
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | include/linux/preempt.h | 41 | ||||
| -rw-r--r-- | include/linux/sched.h | 41 | ||||
| -rw-r--r-- | include/linux/spinlock.h | 14 | ||||
| -rw-r--r-- | kernel/sched/build_policy.c | 1 | ||||
| -rw-r--r-- | kernel/sched/clock.c | 4 | ||||
| -rw-r--r-- | kernel/sched/core.c | 1874 | ||||
| -rw-r--r-- | kernel/sched/core_sched.c | 2 | ||||
| -rw-r--r-- | kernel/sched/cputime.c | 14 | ||||
| -rw-r--r-- | kernel/sched/deadline.c | 8 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 18 | ||||
| -rw-r--r-- | kernel/sched/idle.c | 12 | ||||
| -rw-r--r-- | kernel/sched/loadavg.c | 4 | ||||
| -rw-r--r-- | kernel/sched/pelt.c | 4 | ||||
| -rw-r--r-- | kernel/sched/psi.c | 60 | ||||
| -rw-r--r-- | kernel/sched/rt.c | 22 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 434 | ||||
| -rw-r--r-- | kernel/sched/stats.h | 2 | ||||
| -rw-r--r-- | kernel/sched/syscalls.c | 1699 | ||||
| -rw-r--r-- | kernel/sched/topology.c | 12 | ||||
| -rw-r--r-- | kernel/sched/wait_bit.c | 4 |
23 files changed, 2183 insertions, 2095 deletions
@@ -271,6 +271,9 @@ D: Driver for WaveFront soundcards (Turtle Beach Maui, Tropez, Tropez+) D: Various bugfixes and changes to sound drivers S: USA +N: Daniel Bristot de Oliveira +D: Scheduler contributions, notably: SCHED_DEADLINE + N: Carlos Henrique Bauer E: chbauer@acm.org E: bauer@atlas.unisinos.br diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 1bd225eca34c..740ca2bc2822 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4728,7 +4728,9 @@ none - Limited to cond_resched() calls voluntary - Limited to cond_resched() and might_sleep() calls full - Any section that isn't explicitly preempt disabled - can be preempted anytime. + can be preempted anytime. Tasks will also yield + contended spinlocks (if the critical section isn't + explicitly preempt disabled beyond the lock itself). print-fatal-signals= [KNL] debug: print fatal signals diff --git a/MAINTAINERS b/MAINTAINERS index 73d6d4979bc9..8377529c9b95 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -20047,7 +20047,6 @@ R: Dietmar Eggemann <dietmar.eggemann@arm.com> (SCHED_NORMAL) R: Steven Rostedt <rostedt@goodmis.org> (SCHED_FIFO/SCHED_RR) R: Ben Segall <bsegall@google.com> (CONFIG_CFS_BANDWIDTH) R: Mel Gorman <mgorman@suse.de> (CONFIG_NUMA_BALANCING) -R: Daniel Bristot de Oliveira <bristot@redhat.com> (SCHED_DEADLINE) R: Valentin Schneider <vschneid@redhat.com> (TOPOLOGY) L: linux-kernel@vger.kernel.org S: Maintained diff --git a/include/linux/preempt.h b/include/linux/preempt.h index 7233e9cf1bab..ce76f1a45722 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -481,4 +481,45 @@ DEFINE_LOCK_GUARD_0(preempt, preempt_disable(), preempt_enable()) DEFINE_LOCK_GUARD_0(preempt_notrace, preempt_disable_notrace(), preempt_enable_notrace()) DEFINE_LOCK_GUARD_0(migrate, migrate_disable(), migrate_enable()) +#ifdef CONFIG_PREEMPT_DYNAMIC + +extern bool preempt_model_none(void); +extern bool preempt_model_voluntary(void); +extern bool preempt_model_full(void); + +#else + +static inline bool preempt_model_none(void) +{ + return IS_ENABLED(CONFIG_PREEMPT_NONE); +} +static inline bool preempt_model_voluntary(void) +{ + return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); +} +static inline bool preempt_model_full(void) +{ + return IS_ENABLED(CONFIG_PREEMPT); +} + +#endif + +static inline bool preempt_model_rt(void) +{ + return IS_ENABLED(CONFIG_PREEMPT_RT); +} + +/* + * Does the preemption model allow non-cooperative preemption? + * + * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with + * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the + * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the + * PREEMPT_NONE model. + */ +static inline bool preempt_model_preemptible(void) +{ + return preempt_model_full() || preempt_model_rt(); +} + #endif /* __LINUX_PREEMPT_H */ diff --git a/include/linux/sched.h b/include/linux/sched.h index a5f4b48fca18..76214d7c819d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2064,47 +2064,6 @@ extern int __cond_resched_rwlock_write(rwlock_t *lock); __cond_resched_rwlock_write(lock); \ }) -#ifdef CONFIG_PREEMPT_DYNAMIC - -extern bool preempt_model_none(void); -extern bool preempt_model_voluntary(void); -extern bool preempt_model_full(void); - -#else - -static inline bool preempt_model_none(void) -{ - return IS_ENABLED(CONFIG_PREEMPT_NONE); -} -static inline bool preempt_model_voluntary(void) -{ - return IS_ENABLED(CONFIG_PREEMPT_VOLUNTARY); -} -static inline bool preempt_model_full(void) -{ - return IS_ENABLED(CONFIG_PREEMPT); -} - -#endif - -static inline bool preempt_model_rt(void) -{ - return IS_ENABLED(CONFIG_PREEMPT_RT); -} - -/* - * Does the preemption model allow non-cooperative preemption? - * - * For !CONFIG_PREEMPT_DYNAMIC kernels this is an exact match with - * CONFIG_PREEMPTION; for CONFIG_PREEMPT_DYNAMIC this doesn't work as the - * kernel is *built* with CONFIG_PREEMPTION=y but may run with e.g. the - * PREEMPT_NONE model. - */ -static inline bool preempt_model_preemptible(void) -{ - return preempt_model_full() || preempt_model_rt(); -} - static __always_inline bool need_resched(void) { return unlikely(tif_need_resched()); diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 3fcd20de6ca8..63dd8cf3c3c2 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -462,11 +462,10 @@ static __always_inline int spin_is_contended(spinlock_t *lock) */ static inline int spin_needbreak(spinlock_t *lock) { -#ifdef CONFIG_PREEMPTION + if (!preempt_model_preemptible()) + return 0; + return spin_is_contended(lock); -#else - return 0; -#endif } /* @@ -479,11 +478,10 @@ static inline int spin_needbreak(spinlock_t *lock) */ static inline int rwlock_needbreak(rwlock_t *lock) { -#ifdef CONFIG_PREEMPTION + if (!preempt_model_preemptible()) + return 0; + return rwlock_is_contended(lock); -#else - return 0; -#endif } /* diff --git a/kernel/sched/build_policy.c b/kernel/sched/build_policy.c index d9dc9ab3773f..39c315182b35 100644 --- a/kernel/sched/build_policy.c +++ b/kernel/sched/build_policy.c @@ -52,3 +52,4 @@ #include "cputime.c" #include "deadline.c" +#include "syscalls.c" diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index 3c6193de9cde..a09655b48140 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -340,7 +340,7 @@ again: this_clock = sched_clock_local(my_scd); /* * We must enforce atomic readout on 32-bit, otherwise the - * update on the remote CPU can hit inbetween the readout of + * update on the remote CPU can hit in between the readout of * the low 32-bit and the high 32-bit portion. */ remote_clock = cmpxchg64(&scd->clock, 0, 0); @@ -444,7 +444,7 @@ notrace void sched_clock_tick_stable(void) } /* - * We are going deep-idle (irqs are disabled): + * We are going deep-idle (IRQs are disabled): */ notrace void sched_clock_idle_sleep_event(void) { diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 35a35e36024b..ae5ef3013a55 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2,9 +2,10 @@ /* * kernel/sched/core.c * - * Core kernel scheduler code and related syscalls + * Core kernel CPU scheduler code * * Copyright (C) 1991-2002 Linus Torvalds + * Copyright (C) 1998-2024 Ingo Molnar, Red Hat */ #include <linux/highmem.h> #include <linux/hrtimer_api.h> @@ -706,14 +707,14 @@ static void update_rq_clock_task(struct rq *rq, s64 delta) /* * 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. + * {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 + * 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. @@ -825,7 +826,7 @@ static void __hrtick_start(void *arg) /* * Called to set the hrtick timer state. * - * called with rq->lock held and irqs disabled + * called with rq->lock held and IRQs disabled */ void hrtick_start(struct rq *rq, u64 delay) { @@ -849,7 +850,7 @@ void hrtick_start(struct rq *rq, u64 delay) /* * Called to set the hrtick timer state. * - * called with rq->lock held and irqs disabled + * called with rq->lock held and IRQs disabled */ void hrtick_start(struct rq *rq, u64 delay) { @@ -883,7 +884,7 @@ static inline void hrtick_rq_init(struct rq *rq) #endif /* CONFIG_SCHED_HRTICK */ /* - * cmpxchg based fetch_or, macro so it works for different integer types + * try_cmpxchg based fetch_or() macro so it works for different integer types: */ #define fetch_or(ptr, mask) \ ({ \ @@ -1080,7 +1081,7 @@ void resched_cpu(int cpu) * * 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). + * (as that CPU's timer base may not be up to date wrt jiffies etc). */ int get_nohz_timer_target(void) { @@ -1140,7 +1141,7 @@ static void wake_up_idle_cpu(int cpu) * nohz functions that would need to follow TIF_NR_POLLING * clearing: * - * - On most archs, a simple fetch_or on ti::flags with a + * - On most architectures, a simple fetch_or on ti::flags with a * "0" value would be enough to know if an IPI needs to be sent. * * - x86 needs to perform a last need_resched() check between @@ -1323,30 +1324,27 @@ int tg_nop(struct task_group *tg, void *data) } #endif -static void set_load_weight(struct task_struct *p, bool update_load) +void set_load_weight(struct task_struct *p, bool update_load) { int prio = p->static_prio - MAX_RT_PRIO; - struct load_weight *load = &p->se.load; + struct load_weight lw; - /* - * SCHED_IDLE tasks get minimal weight: - */ if (task_has_idle_policy(p)) { - load->weight = scale_load(WEIGHT_IDLEPRIO); - load->inv_weight = WMULT_IDLEPRIO; - return; + lw.weight = scale_load(WEIGHT_IDLEPRIO); + lw.inv_weight = WMULT_IDLEPRIO; + } else { + lw.weight = scale_load(sched_prio_to_weight[prio]); + lw.inv_weight = sched_prio_to_wmult[prio]; } /* * SCHED_OTHER tasks have to update their load when changing their * weight */ - if (update_load && p->sched_class == &fair_sched_class) { - reweight_task(p, prio); - } else { - load->weight = scale_load(sched_prio_to_weight[prio]); - load->inv_weight = sched_prio_to_wmult[prio]; - } + if (update_load && p->sched_class == &fair_sched_class) + reweight_task(p, &lw); + else + p->se.load = lw; } #ifdef CONFIG_UCLAMP_TASK @@ -1383,7 +1381,7 @@ static unsigned int __maybe_unused sysctl_sched_uclamp_util_max = SCHED_CAPACITY * This knob will not override the system default sched_util_clamp_min defined * above. */ -static unsigned int sysctl_sched_uclamp_util_min_rt_default = SCHED_CAPACITY_SCALE; +unsigned int sysctl_sched_uclamp_util_min_rt_default = SCHED_CAPACITY_SCALE; /* All clamps are required to be less or equal than these values */ static struct uclamp_se uclamp_default[UCLAMP_CNT]; @@ -1408,32 +1406,6 @@ static struct uclamp_se uclamp_default[UCLAMP_CNT]; */ DEFINE_STATIC_KEY_FALSE(sched_uclamp_used); -/* Integer rounded range for each bucket */ -#define UCLAMP_BUCKET_DELTA DIV_ROUND_CLOSEST(SCHED_CAPACITY_SCALE, UCLAMP_BUCKETS) - -#define for_each_clamp_id(clamp_id) \ - for ((clamp_id) = 0; (clamp_id) < UCLAMP_CNT; (clamp_id)++) - -static inline unsigned int uclamp_bucket_id(unsigned int clamp_value) -{ - return min_t(unsigned int, clamp_value / UCLAMP_BUCKET_DELTA, UCLAMP_BUCKETS - 1); -} - -static inline unsigned int uclamp_none(enum uclamp_id clamp_id) -{ - if (clamp_id == UCLAMP_MIN) - return 0; - return SCHED_CAPACITY_SCALE; -} - -static inline void uclamp_se_set(struct uclamp_se *uc_se, - unsigned int value, bool user_defined) -{ - uc_se->value = value; - uc_se->bucket_id = uclamp_bucket_id(value); - uc_se->user_defined = user_defined; -} - static inline unsigned int uclamp_idle_value(struct rq *rq, enum uclamp_id clamp_id, unsigned int clamp_value) @@ -1675,7 +1647,7 @@ static inline void uclamp_rq_dec_id(struct rq *rq, struct task_struct *p, rq_clamp = uclamp_rq_get(rq, clamp_id); /* * Defensive programming: this should never happen. If it happens, - * e.g. due to future modification, warn and fixup the expected value. + * e.g. due to future modification, warn and fix up the expected value. */ SCHED_WARN_ON(bucket->value > rq_clamp); if (bucket->value >= rq_clamp) { @@ -1897,107 +1869,6 @@ undo: } #endif -static int uclamp_validate(struct task_struct *p, - const struct sched_attr *attr) -{ - int util_min = p->uclamp_req[UCLAMP_MIN].value; - int util_max = p->uclamp_req[UCLAMP_MAX].value; - - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { - util_min = attr->sched_util_min; - - if (util_min + 1 > SCHED_CAPACITY_SCALE + 1) - return -EINVAL; - } - - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { - util_max = attr->sched_util_max; - - if (util_max + 1 > SCHED_CAPACITY_SCALE + 1) - return -EINVAL; - } - - if (util_min != -1 && util_max != -1 && util_min > util_max) - return -EINVAL; - - /* - * We have valid uclamp attributes; make sure uclamp is enabled. - * - * We need to do that here, because enabling static branches is a - * blocking operation which obviously cannot be done while holding - * scheduler locks. - */ - static_branch_enable(&sched_uclamp_used); - - return 0; -} - -static bool uclamp_reset(const struct sched_attr *attr, - enum uclamp_id clamp_id, - struct uclamp_se *uc_se) -{ - /* Reset on sched class change for a non user-defined clamp value. */ - if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP)) && - !uc_se->user_defined) - return true; - - /* Reset on sched_util_{min,max} == -1. */ - if (clamp_id == UCLAMP_MIN && - attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN && - attr->sched_util_min == -1) { - return true; - } - - if (clamp_id == UCLAMP_MAX && - attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX && - attr->sched_util_max == -1) { - return true; - } - - return false; -} - -static void __setscheduler_uclamp(struct task_struct *p, - const struct sched_attr *attr) -{ - enum uclamp_id clamp_id; - - for_each_clamp_id(clamp_id) { - struct uclamp_se *uc_se = &p->uclamp_req[clamp_id]; - unsigned int value; - - if (!uclamp_reset(attr, clamp_id, uc_se)) - continue; - - /* - * RT by default have a 100% boost value that could be modified - * at runtime. - */ - if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN)) - value = sysctl_sched_uclamp_util_min_rt_default; - else - value = uclamp_none(clamp_id); - - uclamp_se_set(uc_se, value, false); - - } - - if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP))) - return; - - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN && - attr->sched_util_min != -1) { - uclamp_se_set(&p->uclamp_req[UCLAMP_MIN], - attr->sched_util_min, true); - } - - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX && - attr->sched_util_max != -1) { - uclamp_se_set(&p->uclamp_req[UCLAMP_MAX], - attr->sched_util_max, true); - } -} - static void uclamp_fork(struct task_struct *p) { enum uclamp_id clamp_id; @@ -2065,13 +1936,6 @@ static void __init init_uclamp(void) #else /* !CONFIG_UCLAMP_TASK */ static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) { } static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) { } -static inline int uclamp_validate(struct task_struct *p, - const struct sched_attr *attr) -{ - return -EOPNOTSUPP; -} -static void __setscheduler_uclamp(struct task_struct *p, - const struct sched_attr *attr) { } static inline void uclamp_fork(struct task_struct *p) { } static inline void uclamp_post_fork(struct task_struct *p) { } static inline void init_uclamp(void) { } @@ -2101,7 +1965,7 @@ unsigned long get_wchan(struct task_struct *p) return ip; } -static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) +void enqueue_task(struct rq *rq, struct task_struct *p, int flags) { if (!(flags & ENQUEUE_NOCLOCK)) update_rq_clock(rq); @@ -2118,7 +1982,7 @@ static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) sched_core_enqueue(rq, p); } -static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags) +void dequeue_task(struct rq *rq, struct task_struct *p, int flags) { if (sched_core_enabled(rq)) sched_core_dequeue(rq, p, flags); @@ -2156,52 +2020,6 @@ void deactivate_task(struct rq *rq, struct task_struct *p, int flags) dequeue_task(rq, p, flags); } -static inline int __normal_prio(int policy, int rt_prio, int nice) -{ - int prio; - - if (dl_policy(policy)) - prio = MAX_DL_PRIO - 1; - else if (rt_policy(policy)) - prio = MAX_RT_PRIO - 1 - rt_prio; - else - prio = NICE_TO_PRIO(nice); - - return prio; -} - -/* - * Calculate the expected normal priority: i.e. priority - * without taking RT-inheritance into account. Might be - * boosted by interactivity modifiers. Changes upon fork, - * setprio syscalls, and whenever the interactivity - * estimator recalculates. - */ -static inline int normal_prio(struct task_struct *p) -{ - return __normal_prio(p->policy, p->rt_priority, PRIO_TO_NICE(p->static_prio)); -} - -/* - * Calculate the current priority, i.e. the priority - * taken into account by the scheduler. This value might - * be boosted by RT tasks, or might be boosted by - * interactivity modifiers. 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; -} - /** * task_curr - is this task currently executing on a CPU? * @p: the task in question. @@ -2220,9 +2038,9 @@ inline int task_curr(const struct task_struct *p) * this means any call to check_class_changed() must be followed by a call to * balance_callback(). */ -static inline void check_class_changed(struct rq *rq, struct task_struct *p, - const struct sched_class *prev_class, - int oldprio) +void check_class_changed(struct rq *rq, struct task_struct *p, + const struct sched_class *prev_class, + int oldprio) { if (prev_class != p->sched_class) { if (prev_class->switched_from) @@ -2391,9 +2209,6 @@ unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state static void __do_set_cpus_allowed(struct task_struct *p, struct affinity_context *ctx); -static int __set_cpus_allowed_ptr(struct task_struct *p, - struct affinity_context *ctx); - static void migrate_disable_switch(struct rq *rq, struct task_struct *p) { struct affinity_context ac = { @@ -2408,7 +2223,7 @@ static void migrate_disable_switch(struct rq *rq, struct task_struct *p) return; /* - * Violates locking rules! see comment in __do_set_cpus_allowed(). + * Violates locking rules! See comment in __do_set_cpus_allowed(). */ __do_set_cpus_allowed(p, &ac); } @@ -2575,7 +2390,7 @@ static struct rq *__migrate_task(struct rq *rq, struct rq_flags *rf, } /* - * migration_cpu_stop - this will be executed by a highprio stopper thread + * migration_cpu_stop - this will be executed by a high-prio stopper thread * and performs thread migration by bumping thread off CPU then * 'pushing' onto another runqueue. */ @@ -2820,16 +2635,6 @@ void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) kfree_rcu((union cpumask_rcuhead *)ac.user_mask, rcu); } -static cpumask_t *alloc_user_cpus_ptr(int node) -{ - /* - * See do_set_cpus_allowed() above for the rcu_head usage. - */ - int size = max_t(int, cpumask_size(), sizeof(struct rcu_head)); - - return kmalloc_node(size, GFP_KERNEL, node); -} - int dup_user_cpus_ptr(struct task_struct *dst, struct task_struct *src, int node) { @@ -3198,8 +3003,7 @@ out: * 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, - struct affinity_context *ctx) +int __set_cpus_allowed_ptr(struct task_struct *p, struct affinity_context *ctx) { struct rq_flags rf; struct rq *rq; @@ -3318,9 +3122,6 @@ out_free_mask: free_cpumask_var(new_mask); } -static int -__sched_setaffinity(struct task_struct *p, struct affinity_context *ctx); - /* * Restore the affinity of a task @p which was previously restricted by a * call to force_compatible_cpus_allowed_ptr(). @@ -3700,12 +3501,6 @@ void sched_set_stop_task(int cpu, struct task_struct *stop) #else /* CONFIG_SMP */ -static inline int __set_cpus_allowed_ptr(struct task_struct *p, - struct affinity_context *ctx) -{ - return set_cpus_allowed_ptr(p, ctx->new_mask); -} - static inline void migrate_disable_switch(struct rq *rq, struct task_struct *p) { } static inline bool rq_has_pinned_tasks(struct rq *rq) @@ -3713,11 +3508,6 @@ static inline bool rq_has_pinned_tasks(struct rq *rq) return false; } -static inline cpumask_t *alloc_user_cpus_ptr(int node) -{ - return NULL; -} - #endif /* !CONFIG_SMP */ static void @@ -3900,8 +3690,8 @@ void sched_ttwu_pending(void *arg) * it is possible for select_idle_siblings() to stack a number * of tasks on this CPU during that window. * - * It is ok to clear ttwu_pending when another task pending. - * We will receive IPI after local irq enabled and then enqueue it. + * It is OK to clear ttwu_pending when another task pending. + * We will receive IPI after local IRQ enabled and then enqueue it. * Since now nr_running > 0, idle_cpu() will always get correct result. */ WRITE_ONCE(rq->ttwu_pending, 0); @@ -5094,7 +4884,7 @@ __splice_balance_callbacks(struct rq *rq, bool split) return head; } -static inline struct balance_callback *splice_balance_callbacks(struct rq *rq) +struct balance_callback *splice_balance_callbacks(struct rq *rq) { return __splice_balance_callbacks(rq, true); } @@ -5104,7 +4894,7 @@ static void __balance_callbacks(struct rq *rq) do_balance_callbacks(rq, __splice_balance_callbacks(rq, false)); } -static inline void balance_callbacks(struct rq *rq, struct balance_callback *head) +void balance_callbacks(struct rq *rq, struct balance_callback *head) { unsigned long flags; @@ -5121,15 +4911,6 @@ static inline void __balance_callbacks(struct rq *rq) { } -static inline struct balance_callback *splice_balance_callbacks(struct rq *rq) -{ - return NULL; -} - -static inline void balance_callbacks(struct rq *rq, struct balance_callback *head) -{ -} - #endif static inline void @@ -5232,7 +5013,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev, * * 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 + * 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) @@ -5555,9 +5336,9 @@ EXPORT_PER_CPU_SYMBOL(kernel_cpustat); static inline void prefetch_curr_exec_start(struct task_struct *p) { #ifdef CONFIG_FAIR_GROUP_SCHED - struct sched_entity *curr = (&p->se)->cfs_rq->curr; + struct sched_entity *curr = p->se.cfs_rq->curr; #else - struct sched_entity *curr = (&task_rq(p)->cfs)->curr; + struct sched_entity *curr = task_rq(p)->cfs.curr; #endif prefetch(curr); prefetch(&curr->exec_start); @@ -5578,7 +5359,7 @@ unsigned long long task_sched_runtime(struct task_struct *p) /* * 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. + * 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 @@ -6856,7 +6637,7 @@ 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 + * 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. @@ -7051,9 +6832,9 @@ EXPORT_SYMBOL(dynamic_preempt_schedule_notrace); /* * 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. + * off of IRQ context. + * Note, that this is called and return with IRQs disabled. This will + * protect us against recursive calling from IRQ contexts. */ asmlinkage __visible void __sched preempt_schedule_irq(void) { @@ -7083,7 +6864,7 @@ int default_wake_function(wait_queue_entry_t *curr, unsigned mode, int wake_flag } EXPORT_SYMBOL(default_wake_function); -static void __setscheduler_prio(struct task_struct *p, int prio) +void __setscheduler_prio(struct task_struct *p, int prio) { if (dl_prio(prio)) p->sched_class = &dl_sched_class; @@ -7123,21 +6904,6 @@ void rt_mutex_post_schedule(void) lockdep_assert(fetch_and_set(current->sched_rt_mutex, 0)); } -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 @@ -7187,7 +6953,7 @@ void rt_mutex_setprio(struct task_struct *p, struct task_struct *pi_task) goto out_unlock; /* - * Idle task boosting is a nono in general. There is one + * Idle task boosting is a no-no in general. There is one * exception, when PREEMPT_RT and NOHZ is active: * * The idle task calls get_next_timer_interrupt() and holds @@ -7266,1325 +7032,8 @@ out_unlock: 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) -{ - bool queued, running; - struct rq *rq; - int old_prio; - - 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. - */ - CLASS(task_rq_lock, rq_guard)(p); - rq = rq_guard.rq; - - update_rq_clock(rq); - - /* - * 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 - * SCHED_DEADLINE, SCHED_FIFO or SCHED_RR: - */ - if (task_has_dl_policy(p) || task_has_rt_policy(p)) { - p->static_prio = NICE_TO_PRIO(nice); - return; - } - - queued = task_on_rq_queued(p); - running = task_current(rq, p); - if (queued) - dequeue_task(rq, p, DEQUEUE_SAVE | DEQUEUE_NOCLOCK); - if (running) - put_prev_task(rq, p); - - p->static_prio = NICE_TO_PRIO(nice); - set_load_weight(p, true); - old_prio = p->prio; - p->prio = effective_prio(p); - - if (queued) - enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK); - if (running) - set_next_task(rq, p); - - /* - * If the task increased its priority or is running and - * lowered its priority, then reschedule its CPU: - */ - p->sched_class->prio_changed(rq, p, old_prio); -} -EXPORT_SYMBOL(set_user_nice); - -/* - * is_nice_reduction - check if nice value is an actual reduction - * - * Similar to can_nice() but does not perform a capability check. - * - * @p: task - * @nice: nice value - */ -static bool is_nice_reduction(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)); -} - -/* - * 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) -{ - return is_nice_reduction(p, 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 - -/** - * 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 ... 139] 0/[-20 ... 19] - * fifo, rr [-2 ... -100] [98 ... 0] [1 ... 99] - * deadline -101 -1 0 - */ -int task_prio(const struct task_struct *p) -{ - return p->prio - MAX_RT_PRIO; -} - -/** - * 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; -} - -/** - * available_idle_cpu - is a given CPU idle for enqueuing work. - * @cpu: the CPU in question. - * - * Return: 1 if the CPU is currently idle. 0 otherwise. - */ -int available_idle_cpu(int cpu) -{ - if (!idle_cpu(cpu)) - return 0; - - if (vcpu_is_preempted(cpu)) - return 0; - - 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; -} - -#ifdef CONFIG_SCHED_CORE -int sched_core_idle_cpu(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - - if (sched_core_enabled(rq) && rq->curr == rq->idle) - return 1; - - return idle_cpu(cpu); -} - -#endif - -#ifdef CONFIG_SMP -/* - * This function computes an effective utilization for the given CPU, to be - * used for frequency selection given the linear relation: f = u * f_max. - * - * The scheduler tracks the following metrics: - * - * cpu_util_{cfs,rt,dl,irq}() - * cpu_bw_dl() - * - * Where the cfs,rt and dl util numbers are tracked with the same metric and - * synchronized windows and are thus directly comparable. - * - * The cfs,rt,dl utilization are the running times measured with rq->clock_task - * which excludes things like IRQ and steal-time. These latter are then accrued - * in the irq utilization. - * - * The DL bandwidth number otoh is not a measured metric but a value computed - * based on the task model parameters and gives the minimal utilization - * required to meet deadlines. - */ -unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, - unsigned long *min, - unsigned long *max) -{ - unsigned long util, irq, scale; - struct rq *rq = cpu_rq(cpu); - - scale = arch_scale_cpu_capacity(cpu); - - /* - * Early check to see if IRQ/steal time saturates the CPU, can be - * because of inaccuracies in how we track these -- see - * update_irq_load_avg(). - */ - irq = cpu_util_irq(rq); - if (unlikely(irq >= scale)) { - if (min) - *min = scale; - if (max) - *max = scale; - return scale; - } - - if (min) { - /* - * The minimum utilization returns the highest level between: - * - the computed DL bandwidth needed with the IRQ pressure which - * steals time to the deadline task. - * - The minimum performance requirement for CFS and/or RT. - */ - *min = max(irq + cpu_bw_dl(rq), uclamp_rq_get(rq, UCLAMP_MIN)); - - /* - * When an RT task is runnable and uclamp is not used, we must - * ensure that the task will run at maximum compute capacity. - */ - if (!uclamp_is_used() && rt_rq_is_runnable(&rq->rt)) - *min = max(*min, scale); - } - - /* - * Because the time spend on RT/DL tasks is visible as 'lost' time to - * CFS tasks and we use the same metric to track the effective - * utilization (PELT windows are synchronized) we can directly add them - * to obtain the CPU's actual utilization. - */ - util = util_cfs + cpu_util_rt(rq); - util += cpu_util_dl(rq); - - /* - * The maximum hint is a soft bandwidth requirement, which can be lower - * than the actual utilization because of uclamp_max requirements. - */ - if (max) - *max = min(scale, uclamp_rq_get(rq, UCLAMP_MAX)); - - if (util >= scale) - return scale; - - /* - * There is still idle time; further improve the number by using the - * irq metric. Because IRQ/steal time is hidden from the task clock we - * need to scale the task numbers: - * - * max - irq - * U' = irq + --------- * U - * max - */ - util = scale_irq_capacity(util, irq, scale); - util += irq; - - return min(scale, util); -} - -unsigned long sched_cpu_util(int cpu) -{ - return effective_cpu_util(cpu, cpu_util_cfs(cpu), NULL, NULL); -} -#endif /* CONFIG_SMP */ - -/** - * 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 struct task_struct *find_process_by_pid(pid_t pid) -{ - return pid ? find_task_by_vpid(pid) : current; -} - -static struct task_struct *find_get_task(pid_t pid) -{ - struct task_struct *p; - guard(rcu)(); - - p = find_process_by_pid(pid); - if (likely(p)) - get_task_struct(p); - - return p; -} - -DEFINE_CLASS(find_get_task, struct task_struct *, if (_T) put_task_struct(_T), - find_get_task(pid), pid_t pid) - -/* - * 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; - - if (dl_policy(policy)) - __setparam_dl(p, attr); - else if (fair_policy(policy)) - 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); - set_load_weight(p, true); -} - -/* - * 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; - guard(rcu)(); - - pcred = __task_cred(p); - return (uid_eq(cred->euid, pcred->euid) || - uid_eq(cred->euid, pcred->uid)); -} - -/* - * Allow unprivileged RT tasks to decrease priority. - * Only issue a capable test if needed and only once to avoid an audit - * event on permitted non-privileged operations: - */ -static int user_check_sched_setscheduler(struct task_struct *p, - const struct sched_attr *attr, - int policy, int reset_on_fork) -{ - if (fair_policy(policy)) { - if (attr->sched_nice < task_nice(p) && - !is_nice_reduction(p, attr->sched_nice)) - goto req_priv; - } - - if (rt_policy(policy)) { - unsigned long rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); - - /* Can't set/change the rt policy: */ - if (policy != p->policy && !rlim_rtprio) - goto req_priv; - - /* Can't increase priority: */ - if (attr->sched_priority > p->rt_priority && - attr->sched_priority > rlim_rtprio) - goto req_priv; - } - - /* - * Can't set/change SCHED_DEADLINE policy at all for now - * (safest behavior); in the future we would like to allow - * unprivileged DL tasks to increase their relative deadline - * or reduce their runtime (both ways reducing utilization) - */ - if (dl_policy(policy)) - goto req_priv; - - /* - * Treat SCHED_IDLE as nice 20. Only allow a switch to - * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. - */ - if (task_has_idle_policy(p) && !idle_policy(policy)) { - if (!is_nice_reduction(p, task_nice(p))) - goto req_priv; - } - - /* Can't change other user's priorities: */ - if (!check_same_owner(p)) - goto req_priv; - - /* Normal users shall not reset the sched_reset_on_fork flag: */ - if (p->sched_reset_on_fork && !reset_on_fork) - goto req_priv; - - return 0; - -req_priv: - if (!capable(CAP_SYS_NICE)) - return -EPERM; - - return 0; -} - -static int __sched_setscheduler(struct task_struct *p, - const struct sched_attr *attr, - bool user, bool pi) -{ - int oldpolicy = -1, policy = attr->sched_policy; - int retval, oldprio, newprio, queued, running; - const struct sched_class *prev_class; - struct balance_callback *head; - struct rq_flags rf; - int reset_on_fork; - int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE | DEQUEUE_NOCLOCK; - struct rq *rq; - bool cpuset_locked = false; - - /* The pi code expects interrupts enabled */ - BUG_ON(pi && in_interrupt()); -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_FLAG_RESET_ON_FORK); - - if (!valid_policy(policy)) - return -EINVAL; - } - - if (attr->sched_flags & ~(SCHED_FLAG_ALL | SCHED_FLAG_SUGOV)) - return -EINVAL; - - /* - * Valid priorities for SCHED_FIFO and SCHED_RR are - * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL, - * SCHED_BATCH and SCHED_IDLE is 0. - */ - if (attr->sched_priority > MAX_RT_PRIO-1) - return -EINVAL; - if ((dl_policy(policy) && !__checkparam_dl(attr)) || - (rt_policy(policy) != (attr->sched_priority != 0))) - return -EINVAL; - - if (user) { - retval = user_check_sched_setscheduler(p, attr, policy, reset_on_fork); - if (retval) - return retval; - - if (attr->sched_flags & SCHED_FLAG_SUGOV) - return -EINVAL; - - retval = security_task_setscheduler(p); - if (retval) - return retval; - } - - /* Update task specific "requested" clamps */ - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) { - retval = uclamp_validate(p, attr); - if (retval) - return retval; - } - - /* - * SCHED_DEADLINE bandwidth accounting relies on stable cpusets - * information. - */ - if (dl_policy(policy) || dl_policy(p->policy)) { - cpuset_locked = true; - cpuset_lock(); - } - - /* - * Make sure no PI-waiters arrive (or leave) while we are - * changing the priority of the task: - * - * To be able to change p->policy safely, the appropriate - * runqueue lock must be held. - */ - rq = task_rq_lock(p, &rf); - update_rq_clock(rq); - - /* - * 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, - * but store a possible modification of reset_on_fork. - */ - if (unlikely(policy == p->policy)) { - if (fair_policy(policy) && attr->sched_nice != task_nice(p)) - goto change; - if (rt_policy(policy) && attr->sched_priority != p->rt_priority) - goto change; - if (dl_policy(policy) && dl_param_changed(p, attr)) - goto change; - if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) - goto change; - - p->sched_reset_on_fork = reset_on_fork; - retval = 0; - goto unlock; - } -change: - - if (user) { -#ifdef CONFIG_RT_GROUP_SCHED - /* - * Do not allow realtime tasks into groups that have no runtime - * assigned. - */ - if (rt_bandwidth_enabled() && rt_policy(policy) && - task_group(p)->rt_bandwidth.rt_runtime == 0 && - !task_group_is_autogroup(task_group(p))) { - retval = -EPERM; - goto unlock; - } -#endif -#ifdef CONFIG_SMP - if (dl_bandwidth_enabled() && dl_policy(policy) && - !(attr->sched_flags & SCHED_FLAG_SUGOV)) { - cpumask_t *span = rq->rd->span; - - /* - * Don't allow tasks with an affinity mask smaller than - * the entire root_domain to become SCHED_DEADLINE. We - * will also fail if there's no bandwidth available. - */ - if (!cpumask_subset(span, p->cpus_ptr) || - rq->rd->dl_bw.bw == 0) { - retval = -EPERM; - goto unlock; - } - } -#endif - } - - /* Re-check policy now with rq lock held: */ - if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { - policy = oldpolicy = -1; - task_rq_unlock(rq, p, &rf); - if (cpuset_locked) - cpuset_unlock(); - goto recheck; - } - - /* - * If setscheduling to SCHED_DEADLINE (or changing the parameters - * of a SCHED_DEADLINE task) we need to check if enough bandwidth - * is available. - */ - if ((dl_policy(policy) || dl_task(p)) && sched_dl_overflow(p, policy, attr)) { - retval = -EBUSY; - goto unlock; - } - - p->sched_reset_on_fork = reset_on_fork; - oldprio = p->prio; - - newprio = __normal_prio(policy, attr->sched_priority, attr->sched_nice); - 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. - */ - newprio = rt_effective_prio(p, newprio); - if (newprio == oldprio) - queue_flags &= ~DEQUEUE_MOVE; - } - - queued = task_on_rq_queued(p); - running = task_current(rq, p); - if (queued) - dequeue_task(rq, p, queue_flags); - if (running) - put_prev_task(rq, p); - - prev_class = p->sched_class; - - if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) { - __setscheduler_params(p, attr); - __setscheduler_prio(p, newprio); - } - __setscheduler_uclamp(p, attr); - - if (queued) { - /* - * We enqueue to tail when the priority of a task is - * increased (user space view). - */ - if (oldprio < p->prio) - queue_flags |= ENQUEUE_HEAD; - - enqueue_task(rq, p, queue_flags); - } - if (running) - set_next_task(rq, p); - - check_class_changed(rq, p, prev_class, oldprio); - - /* Avoid rq from going away on us: */ - preempt_disable(); - head = splice_balance_callbacks(rq); - task_rq_unlock(rq, p, &rf); - - if (pi) { - if (cpuset_locked) - cpuset_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_rq_unlock(rq, p, &rf); - if (cpuset_locked) - cpuset_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); -} -EXPORT_SYMBOL_GPL(sched_setattr_nocheck); - -/** - * 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; - - if (!param || pid < 0) - return -EINVAL; - if (copy_from_user(&lparam, param, sizeof(struct sched_param))) - return -EFAULT; - - CLASS(find_get_task, p)(pid); - if (!p) - return -ESRCH; - - return sched_setscheduler(p, policy, &lparam); -} - -/* - * 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; - } - - if ((attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) && - size < SCHED_ATTR_SIZE_VER1) - return -EINVAL; - - /* - * 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, MIN_NICE, MAX_NICE); - - return 0; - -err_size: - put_user(sizeof(*attr), &uattr->size); - return -E2BIG; -} - -static void get_params(struct task_struct *p, struct sched_attr *attr) -{ - if (task_has_dl_policy(p)) - __getparam_dl(p, attr); - else if (task_has_rt_policy(p)) - attr->sched_priority = p->rt_priority; - else - attr->sched_nice = task_nice(p); -} - -/** - * sys_sched_setscheduler - set/change the scheduler policy and RT priority - * @pid: the pid in question. - * @policy: new policy. - * @param: structure containing the new RT priority. - * - * Return: 0 on success. An error code otherwise. - */ -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. - * @flags: for future extension. - */ -SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, - unsigned int, flags) -{ - struct sched_attr attr; - 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; - if (attr.sched_flags & SCHED_FLAG_KEEP_POLICY) - attr.sched_policy = SETPARAM_POLICY; - - CLASS(find_get_task, p)(pid); - if (!p) - return -ESRCH; - - if (attr.sched_flags & SCHED_FLAG_KEEP_PARAMS) - get_params(p, &attr); - - return sched_setattr(p, &attr); -} - -/** - * 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; - - if (pid < 0) - return -EINVAL; - - guard(rcu)(); - p = find_process_by_pid(pid); - if (!p) - return -ESRCH; - - retval = security_task_getscheduler(p); - if (!retval) { - retval = p->policy; - if (p->sched_reset_on_fork) - retval |= SCHED_RESET_ON_FORK; - } - return retval; -} - -/** - * sys_sched_getparam - 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; - - if (!param || pid < 0) - return -EINVAL; - - scoped_guard (rcu) { - p = find_process_by_pid(pid); - if (!p) - return -ESRCH; - - retval = security_task_getscheduler(p); - if (retval) - return retval; - - if (task_has_rt_policy(p)) - lp.sched_priority = p->rt_priority; - } - - /* - * This one might sleep, we cannot do it with a spinlock held ... - */ - return copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; -} - -/* - * 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; - - scoped_guard (rcu) { - p = find_process_by_pid(pid); - if (!p) - return -ESRCH; - - retval = security_task_getscheduler(p); - if (retval) - return retval; - - kattr.sched_policy = p->policy; - if (p->sched_reset_on_fork) - kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; - get_params(p, &kattr); - kattr.sched_flags &= SCHED_FLAG_ALL; - -#ifdef CONFIG_UCLAMP_TASK - /* - * This could race with another potential updater, but this is fine - * because it'll correctly read the old or the new value. We don't need - * to guarantee who wins the race as long as it doesn't return garbage. - */ - kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value; - kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value; -#endif - } - - return sched_attr_copy_to_user(uattr, &kattr, usize); -} - -#ifdef CONFIG_SMP -int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) -{ - /* - * If the task isn't a deadline task or admission control is - * disabled then we don't care about affinity changes. - */ - if (!task_has_dl_policy(p) || !dl_bandwidth_enabled()) - return 0; - - /* - * Since bandwidth control happens on root_domain basis, - * if admission test is enabled, we only admit -deadline - * tasks allowed to run on all the CPUs in the task's - * root_domain. - */ - guard(rcu)(); - if (!cpumask_subset(task_rq(p)->rd->span, mask)) - return -EBUSY; - - return 0; -} #endif -static int -__sched_setaffinity(struct task_struct *p, struct affinity_context *ctx) -{ - int retval; - cpumask_var_t cpus_allowed, new_mask; - - if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) - return -ENOMEM; - - if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { - retval = -ENOMEM; - goto out_free_cpus_allowed; - } - - cpuset_cpus_allowed(p, cpus_allowed); - cpumask_and(new_mask, ctx->new_mask, cpus_allowed); - - ctx->new_mask = new_mask; - ctx->flags |= SCA_CHECK; - - retval = dl_task_check_affinity(p, new_mask); - if (retval) - goto out_free_new_mask; - - retval = __set_cpus_allowed_ptr(p, ctx); - if (retval) - goto out_free_new_mask; - - 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 cpumask to the cpuset's cpus_allowed. - */ - cpumask_copy(new_mask, cpus_allowed); - - /* - * If SCA_USER is set, a 2nd call to __set_cpus_allowed_ptr() - * will restore the previous user_cpus_ptr value. - * - * In the unlikely event a previous user_cpus_ptr exists, - * we need to further restrict the mask to what is allowed - * by that old user_cpus_ptr. - */ - if (unlikely((ctx->flags & SCA_USER) && ctx->user_mask)) { - bool empty = !cpumask_and(new_mask, new_mask, - ctx->user_mask); - - if (WARN_ON_ONCE(empty)) - cpumask_copy(new_mask, cpus_allowed); - } - __set_cpus_allowed_ptr(p, ctx); - retval = -EINVAL; - } - -out_free_new_mask: - free_cpumask_var(new_mask); -out_free_cpus_allowed: - free_cpumask_var(cpus_allowed); - return retval; -} - -long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) -{ - struct affinity_context ac; - struct cpumask *user_mask; - int retval; - - CLASS(find_get_task, p)(pid); - if (!p) - return -ESRCH; - - if (p->flags & PF_NO_SETAFFINITY) - return -EINVAL; - - if (!check_same_owner(p)) { - guard(rcu)(); - if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) - return -EPERM; - } - - retval = security_task_setscheduler(p); - if (retval) - return retval; - - /* - * With non-SMP configs, user_cpus_ptr/user_mask isn't used and - * alloc_user_cpus_ptr() returns NULL. - */ - user_mask = alloc_user_cpus_ptr(NUMA_NO_NODE); - if (user_mask) { - cpumask_copy(user_mask, in_mask); - } else if (IS_ENABLED(CONFIG_SMP)) { - return -ENOMEM; - } - - ac = (struct affinity_context){ - .new_mask = in_mask, - .user_mask = user_mask, - .flags = SCA_USER, - }; - - retval = __sched_setaffinity(p, &ac); - kfree(ac.user_mask); - - 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, struct cpumask *mask) -{ - struct task_struct *p; - int retval; - - guard(rcu)(); - p = find_process_by_pid(pid); - if (!p) - return -ESRCH; - - retval = security_task_getscheduler(p); - if (retval) - return retval; - - guard(raw_spinlock_irqsave)(&p->pi_lock); - cpumask_and(mask, &p->cpus_mask, cpu_active_mask); - - return 0; -} - -/** - * 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 (!zalloc_cpumask_var(&mask, GFP_KERNEL)) - return -ENOMEM; - - ret = sched_getaffinity(pid, mask); - if (ret == 0) { - unsigned int retlen = min(len, cpumask_size()); - - if (copy_to_user(user_mask_ptr, cpumask_bits(mask), retlen)) - ret = -EFAULT; - else - ret = retlen; - } - free_cpumask_var(mask); - - return ret; -} - -static void do_sched_yield(void) -{ - struct rq_flags rf; - struct rq *rq; - - rq = this_rq_lock_irq(&rf); - - schedstat_inc(rq->yld_count); - current->sched_class->yield_task(rq); - - preempt_disable(); - rq_unlock_irq(rq, &rf); - 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) { @@ -8907,105 +7356,11 @@ PREEMPT_MODEL_ACCESSOR(none); PREEMPT_MODEL_ACCESSOR(voluntary); PREEMPT_MODEL_ACCESSOR(full); -#else /* !CONFIG_PREEMPT_DYNAMIC */ +#else /* !CONFIG_PREEMPT_DYNAMIC: */ static inline void preempt_dynamic_init(void) { } -#endif /* #ifdef CONFIG_PREEMPT_DYNAMIC */ - -/** - * 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. - * - * 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) -{ - struct task_struct *curr = current; - struct rq *rq, *p_rq; - int yielded = 0; - - scoped_guard (irqsave) { - rq = this_rq(); - -again: - p_rq = task_rq(p); - /* - * If we're the only runnable task on the rq and target rq also - * has only one task, there's absolutely no point in yielding. - */ - if (rq->nr_running == 1 && p_rq->nr_running == 1) - return -ESRCH; - - guard(double_rq_lock)(rq, p_rq); - if (task_rq(p) != p_rq) - goto again; - - if (!curr->sched_class->yield_to_task) - return 0; - - if (curr->sched_class != p->sched_class) - return 0; - - if (task_on_cpu(p_rq, p) || !task_is_running(p)) - return 0; - - yielded = curr->sched_class->yield_to_task(rq, p); - if (yielded) { - schedstat_inc(rq->yld_count); - /* - * Make p's CPU reschedule; pick_next_entity - * takes care of fairness. - */ - if (preempt && rq != p_rq) - resched_curr(p_rq); - } - } - - if (yielded) - schedule(); - - return yielded; -} -EXPORT_SYMBOL_GPL(yield_to); +#endif /* CONFIG_PREEMPT_DYNAMIC */ int io_schedule_prepare(void) { @@ -9048,123 +7403,6 @@ void __sched io_schedule(void) } 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_DEADLINE: - 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_DEADLINE: - case SCHED_NORMAL: - case SCHED_BATCH: - case SCHED_IDLE: - ret = 0; - } - return ret; -} - -static int sched_rr_get_interval(pid_t pid, struct timespec64 *t) -{ - unsigned int time_slice = 0; - int retval; - - if (pid < 0) - return -EINVAL; - - scoped_guard (rcu) { - struct task_struct *p = find_process_by_pid(pid); - if (!p) - return -ESRCH; - - retval = security_task_getscheduler(p); - if (retval) - return retval; - - scoped_guard (task_rq_lock, p) { - struct rq *rq = scope.rq; - if (p->sched_class->get_rr_interval) - time_slice = p->sched_class->get_rr_interval(rq, p); - } - } - - jiffies_to_timespec64(time_slice, t); - return 0; -} - -/** - * sys_sched_rr_get_interval - return the default timeslice of a process. - * @pid: pid of the process. - * @interval: userspace pointer to the timeslice value. - * - * this syscall writes the default timeslice value of a given process - * into the user-space timespec buffer. A value of '0' means infinity. - * - * 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; @@ -9732,7 +7970,7 @@ int sched_cpu_deactivate(unsigned int cpu) * 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. + * Do sync before park smpboot threads to take care the RCU boost case. */ synchronize_rcu(); @@ -9807,7 +8045,7 @@ int sched_cpu_wait_empty(unsigned int cpu) * 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 + * stable. We need to take the tear-down 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". @@ -10001,7 +8239,7 @@ void __init sched_init(void) /* * How much CPU bandwidth does root_task_group get? * - * In case of task-groups formed thr' the cgroup filesystem, it + * In case of task-groups formed through the cgroup filesystem, it * gets 100% of the CPU resources in the system. This overall * system CPU resource is divided among the tasks of * root_task_group and its child task-groups in a fair manner, @@ -10303,7 +8541,7 @@ void normalize_rt_tasks(void) #if defined(CONFIG_KGDB_KDB) /* - * These functions are only useful for kdb. + * These functions are only useful for KDB. * * They can only be called when the whole system has been * stopped - every CPU needs to be quiescent, and no scheduling @@ -10411,7 +8649,7 @@ void sched_online_group(struct task_group *tg, struct task_group *parent) online_fair_sched_group(tg); } -/* rcu callback to free various structures associated with a task group */ +/* RCU callback to free various structures associated with a task group */ static void sched_unregister_group_rcu(struct rcu_head *rhp) { /* Now it should be safe to free those cfs_rqs: */ @@ -11529,10 +9767,10 @@ const int sched_prio_to_weight[40] = { }; /* - * Inverse (2^32/x) values of the sched_prio_to_weight[] array, precalculated. + * Inverse (2^32/x) values of the sched_prio_to_weight[] array, pre-calculated. * * In cases where the weight does not change often, we can use the - * precalculated inverse to speed up arithmetics by turning divisions + * pre-calculated inverse to speed up arithmetics by turning divisions * into multiplications: */ const u32 sched_prio_to_wmult[40] = { @@ -11788,16 +10026,16 @@ void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) /* * Move the src cid if the dst cid is unset. This keeps id * allocation closest to 0 in cases where few threads migrate around - * many cpus. + * many CPUs. * * If destination cid is already set, we may have to just clear * the src cid to ensure compactness in frequent migrations * scenarios. * * It is not useful to clear the src cid when the number of threads is - * greater or equal to the number of allowed cpus, because user-space + * greater or equal to the number of allowed CPUs, because user-space * can expect that the number of allowed cids can reach the number of - * allowed cpus. + * allowed CPUs. */ dst_pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(dst_rq)); dst_cid = READ_ONCE(dst_pcpu_cid->cid); diff --git a/kernel/sched/core_sched.c b/kernel/sched/core_sched.c index a57fd8f27498..1ef98a93eb1d 100644 --- a/kernel/sched/core_sched.c +++ b/kernel/sched/core_sched.c @@ -279,7 +279,7 @@ void __sched_core_account_forceidle(struct rq *rq) continue; /* - * Note: this will account forceidle to the current cpu, even + * Note: this will account forceidle to the current CPU, even * if it comes from our SMT sibling. */ __account_forceidle_time(p, delta); diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index aa48b2ec879d..a5e00293ae43 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -14,11 +14,11 @@ * They are only modified in vtime_account, on corresponding CPU * with interrupts disabled. So, writes are safe. * They are read and saved off onto struct rq in update_rq_clock(). - * This may result in other CPU reading this CPU's irq time and can + * This may result in other CPU reading this CPU's IRQ time and can * race with irq/vtime_account on this CPU. We would either get old - * or new value with a side effect of accounting a slice of irq time to wrong - * task when irq is in progress while we read rq->clock. That is a worthy - * compromise in place of having locks on each irq in account_system_time. + * or new value with a side effect of accounting a slice of IRQ time to wrong + * task when IRQ is in progress while we read rq->clock. That is a worthy + * compromise in place of having locks on each IRQ in account_system_time. */ DEFINE_PER_CPU(struct irqtime, cpu_irqtime); @@ -269,7 +269,7 @@ static __always_inline u64 steal_account_process_time(u64 maxtime) } /* - * Account how much elapsed time was spent in steal, irq, or softirq time. + * Account how much elapsed time was spent in steal, IRQ, or softirq time. */ static inline u64 account_other_time(u64 max) { @@ -370,7 +370,7 @@ void thread_group_cputime(struct task_struct *tsk, struct task_cputime *times) * Check for hardirq is done both for system and user time as there is * no timer going off while we are on hardirq and hence we may never get an * opportunity to update it solely in system time. - * p->stime and friends are only updated on system time and not on irq + * p->stime and friends are only updated on system time and not on IRQ * softirq as those do not count in task exec_runtime any more. */ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, @@ -380,7 +380,7 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick, /* * When returning from idle, many ticks can get accounted at - * once, including some ticks of steal, irq, and softirq time. + * once, including some ticks of steal, IRQ, and softirq time. * Subtract those ticks from the amount of time accounted to * idle, or potentially user or system time. Due to rounding, * other time can exceed ticks occasionally. diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 9bedd148f007..f59e5c19d944 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -708,7 +708,7 @@ static struct rq *dl_task_offline_migration(struct rq *rq, struct task_struct *p } /* - * And we finally need to fixup root_domain(s) bandwidth accounting, + * And we finally need to fix up root_domain(s) bandwidth accounting, * since p is still hanging out in the old (now moved to default) root * domain. */ @@ -992,7 +992,7 @@ static inline bool dl_is_implicit(struct sched_dl_entity *dl_se) * is detected, the runtime and deadline need to be updated. * * If the task has an implicit deadline, i.e., deadline == period, the Original - * CBS is applied. the runtime is replenished and a new absolute deadline is + * CBS is applied. The runtime is replenished and a new absolute deadline is * set, as in the previous cases. * * However, the Original CBS does not work properly for tasks with @@ -1294,7 +1294,7 @@ int dl_runtime_exceeded(struct sched_dl_entity *dl_se) * Since rq->dl.running_bw and rq->dl.this_bw contain utilizations multiplied * by 2^BW_SHIFT, the result has to be shifted right by BW_SHIFT. * Since rq->dl.bw_ratio contains 1 / Umax multiplied by 2^RATIO_SHIFT, dl_bw - * is multiped by rq->dl.bw_ratio and shifted right by RATIO_SHIFT. + * is multiplied by rq->dl.bw_ratio and shifted right by RATIO_SHIFT. * Since delta is a 64 bit variable, to have an overflow its value should be * larger than 2^(64 - 20 - 8), which is more than 64 seconds. So, overflow is * not an issue here. @@ -2493,7 +2493,7 @@ static void pull_dl_task(struct rq *this_rq) src_rq = cpu_rq(cpu); /* - * It looks racy, abd it is! However, as in sched_rt.c, + * It looks racy, and it is! However, as in sched_rt.c, * we are fine with this. */ if (this_rq->dl.dl_nr_running && diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 24dda708b699..9057584ec06d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -61,7 +61,7 @@ * Options are: * * SCHED_TUNABLESCALING_NONE - unscaled, always *1 - * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus) + * SCHED_TUNABLESCALING_LOG - scaled logarithmically, *1+ilog(ncpus) * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus * * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) @@ -3835,15 +3835,14 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, } } -void reweight_task(struct task_struct *p, int prio) +void reweight_task(struct task_struct *p, const struct load_weight *lw) { struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); struct load_weight *load = &se->load; - unsigned long weight = scale_load(sched_prio_to_weight[prio]); - reweight_entity(cfs_rq, se, weight); - load->inv_weight = sched_prio_to_wmult[prio]; + reweight_entity(cfs_rq, se, lw->weight); + load->inv_weight = lw->inv_weight; } static inline int throttled_hierarchy(struct cfs_rq *cfs_rq); @@ -8719,7 +8718,7 @@ static bool yield_to_task_fair(struct rq *rq, struct task_struct *p) * topology where each level pairs two lower groups (or better). This results * in O(log n) layers. Furthermore we reduce the number of CPUs going up the * tree to only the first of the previous level and we decrease the frequency - * of load-balance at each level inv. proportional to the number of CPUs in + * of load-balance at each level inversely proportional to the number of CPUs in * the groups. * * This yields: @@ -11886,6 +11885,13 @@ static void kick_ilb(unsigned int flags) return; /* + * Don't bother if no new NOHZ balance work items for ilb_cpu, + * i.e. all bits in flags are already set in ilb_cpu. + */ + if ((atomic_read(nohz_flags(ilb_cpu)) & flags) == flags) + return; + + /* * Access to rq::nohz_csd is serialized by NOHZ_KICK_MASK; he who sets * the first flag owns it; cleared by nohz_csd_func(). */ diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 6135fbe83d68..6e78d071beb5 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -172,19 +172,13 @@ static void cpuidle_idle_call(void) /* * Check if the idle task must be rescheduled. If it is the - * case, exit the function after re-enabling the local irq. + * case, exit the function after re-enabling the local IRQ. */ if (need_resched()) { local_irq_enable(); return; } - /* - * The RCU framework needs to be told that we are entering an idle - * section, so no more rcu read side critical sections and one more - * step to the grace period - */ - if (cpuidle_not_available(drv, dev)) { tick_nohz_idle_stop_tick(); @@ -244,7 +238,7 @@ exit_idle: __current_set_polling(); /* - * It is up to the idle functions to reenable local interrupts + * It is up to the idle functions to re-enable local interrupts */ if (WARN_ON_ONCE(irqs_disabled())) local_irq_enable(); @@ -320,7 +314,7 @@ static void do_idle(void) rcu_nocb_flush_deferred_wakeup(); /* - * In poll mode we reenable interrupts and spin. Also if we + * In poll mode we re-enable interrupts and spin. Also if we * detected in the wakeup from idle path that the tick * broadcast device expired for us, we don't want to go deep * idle as we know that the IPI is going to arrive right away. diff --git a/kernel/sched/loadavg.c b/kernel/sched/loadavg.c index ca9da66cc894..c48900b856a2 100644 --- a/kernel/sched/loadavg.c +++ b/kernel/sched/loadavg.c @@ -45,7 +45,7 @@ * again, being late doesn't loose the delta, just wrecks the sample. * * - cpu_rq()->nr_uninterruptible isn't accurately tracked per-CPU because - * this would add another cross-CPU cacheline miss and atomic operation + * this would add another cross-CPU cache-line miss and atomic operation * to the wakeup path. Instead we increment on whatever CPU the task ran * when it went into uninterruptible state and decrement on whatever CPU * did the wakeup. This means that only the sum of nr_uninterruptible over @@ -62,7 +62,7 @@ EXPORT_SYMBOL(avenrun); /* should be removed */ /** * get_avenrun - get the load average array - * @loads: pointer to dest load array + * @loads: pointer to destination load array * @offset: offset to add * @shift: shift count to shift the result left * diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c index ef00382de595..fa52906a4478 100644 --- a/kernel/sched/pelt.c +++ b/kernel/sched/pelt.c @@ -417,7 +417,7 @@ int update_hw_load_avg(u64 now, struct rq *rq, u64 capacity) #ifdef CONFIG_HAVE_SCHED_AVG_IRQ /* - * irq: + * IRQ: * * util_sum = \Sum se->avg.util_sum but se->avg.util_sum is not tracked * util_sum = cpu_scale * load_sum @@ -432,7 +432,7 @@ int update_irq_load_avg(struct rq *rq, u64 running) int ret = 0; /* - * We can't use clock_pelt because irq time is not accounted in + * We can't use clock_pelt because IRQ time is not accounted in * clock_task. Instead we directly scale the running time to * reflect the real amount of computation */ diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 507d7b8d79af..020d58967d4e 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -41,7 +41,7 @@ * What it means for a task to be productive is defined differently * for each resource. For IO, productive means a running task. For * memory, productive means a running task that isn't a reclaimer. For - * CPU, productive means an oncpu task. + * CPU, productive means an on-CPU task. * * Naturally, the FULL state doesn't exist for the CPU resource at the * system level, but exist at the cgroup level. At the cgroup level, @@ -49,7 +49,7 @@ * resource which is being used by others outside of the cgroup or * throttled by the cgroup cpu.max configuration. * - * The percentage of wallclock time spent in those compound stall + * The percentage of wall clock time spent in those compound stall * states gives pressure numbers between 0 and 100 for each resource, * where the SOME percentage indicates workload slowdowns and the FULL * percentage indicates reduced CPU utilization: @@ -218,28 +218,32 @@ void __init psi_init(void) group_init(&psi_system); } -static bool test_state(unsigned int *tasks, enum psi_states state, bool oncpu) +static u32 test_states(unsigned int *tasks, u32 state_mask) { - switch (state) { - case PSI_IO_SOME: - return unlikely(tasks[NR_IOWAIT]); - case PSI_IO_FULL: - return unlikely(tasks[NR_IOWAIT] && !tasks[NR_RUNNING]); - case PSI_MEM_SOME: - return unlikely(tasks[NR_MEMSTALL]); - case PSI_MEM_FULL: - return unlikely(tasks[NR_MEMSTALL] && - tasks[NR_RUNNING] == tasks[NR_MEMSTALL_RUNNING]); - case PSI_CPU_SOME: - return unlikely(tasks[NR_RUNNING] > oncpu); - case PSI_CPU_FULL: - return unlikely(tasks[NR_RUNNING] && !oncpu); - case PSI_NONIDLE: - return tasks[NR_IOWAIT] || tasks[NR_MEMSTALL] || - tasks[NR_RUNNING]; - default: - return false; + const bool oncpu = state_mask & PSI_ONCPU; + + if (tasks[NR_IOWAIT]) { + state_mask |= BIT(PSI_IO_SOME); + if (!tasks[NR_RUNNING]) + state_mask |= BIT(PSI_IO_FULL); + } + + if (tasks[NR_MEMSTALL]) { + state_mask |= BIT(PSI_MEM_SOME); + if (tasks[NR_RUNNING] == tasks[NR_MEMSTALL_RUNNING]) + state_mask |= BIT(PSI_MEM_FULL); } + + if (tasks[NR_RUNNING] > oncpu) + state_mask |= BIT(PSI_CPU_SOME); + + if (tasks[NR_RUNNING] && !oncpu) + state_mask |= BIT(PSI_CPU_FULL); + + if (tasks[NR_IOWAIT] || tasks[NR_MEMSTALL] || tasks[NR_RUNNING]) + state_mask |= BIT(PSI_NONIDLE); + + return state_mask; } static void get_recent_times(struct psi_group *group, int cpu, @@ -345,7 +349,7 @@ static void collect_percpu_times(struct psi_group *group, /* * Collect the per-cpu time buckets and average them into a - * single time sample that is normalized to wallclock time. + * single time sample that is normalized to wall clock time. * * For averaging, each CPU is weighted by its non-idle time in * the sampling period. This eliminates artifacts from uneven @@ -770,7 +774,6 @@ static void psi_group_change(struct psi_group *group, int cpu, { struct psi_group_cpu *groupc; unsigned int t, m; - enum psi_states s; u32 state_mask; lockdep_assert_rq_held(cpu_rq(cpu)); @@ -842,10 +845,7 @@ static void psi_group_change(struct psi_group *group, int cpu, return; } - for (s = 0; s < NR_PSI_STATES; s++) { - if (test_state(groupc->tasks, s, state_mask & PSI_ONCPU)) - state_mask |= (1 << s); - } + state_mask = test_states(groupc->tasks, state_mask); /* * Since we care about lost potential, a memstall is FULL @@ -1205,7 +1205,7 @@ void psi_cgroup_restart(struct psi_group *group) /* * After we disable psi_group->enabled, we don't actually * stop percpu tasks accounting in each psi_group_cpu, - * instead only stop test_state() loop, record_times() + * instead only stop test_states() loop, record_times() * and averaging worker, see psi_group_change() for details. * * When disable cgroup PSI, this function has nothing to sync @@ -1213,7 +1213,7 @@ void psi_cgroup_restart(struct psi_group *group) * would see !psi_group->enabled and only do task accounting. * * When re-enable cgroup PSI, this function use psi_group_change() - * to get correct state mask from test_state() loop on tasks[], + * to get correct state mask from test_states() loop on tasks[], * and restart groupc->state_start from now, use .clear = .set = 0 * here since no task status really changed. */ diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index aa4c1c874fa4..63e49c8ffc4d 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -140,7 +140,7 @@ void init_rt_rq(struct rt_rq *rt_rq) INIT_LIST_HEAD(array->queue + i); __clear_bit(i, array->bitmap); } - /* delimiter for bitsearch: */ + /* delimiter for bit-search: */ __set_bit(MAX_RT_PRIO, array->bitmap); #if defined CONFIG_SMP @@ -1135,7 +1135,7 @@ dec_rt_prio(struct rt_rq *rt_rq, int prio) /* * This may have been our highest task, and therefore - * we may have some recomputation to do + * we may have some re-computation to do */ if (prio == prev_prio) { struct rt_prio_array *array = &rt_rq->active; @@ -1571,7 +1571,7 @@ select_task_rq_rt(struct task_struct *p, int cpu, int flags) * * For equal prio tasks, we just let the scheduler sort it out. * - * Otherwise, just let it ride on the affined RQ and the + * Otherwise, just let it ride on the affine RQ and the * post-schedule router will push the preempted task away * * This test is optimistic, if we get it wrong the load-balancer @@ -2147,14 +2147,14 @@ static void push_rt_tasks(struct rq *rq) * if its the only CPU with multiple RT tasks queued, and a large number * of CPUs scheduling a lower priority task at the same time. * - * Each root domain has its own irq work function that can iterate over + * Each root domain has its own IRQ work function that can iterate over * all CPUs with RT overloaded tasks. Since all CPUs with overloaded RT * task must be checked if there's one or many CPUs that are lowering - * their priority, there's a single irq work iterator that will try to + * their priority, there's a single IRQ work iterator that will try to * push off RT tasks that are waiting to run. * * When a CPU schedules a lower priority task, it will kick off the - * irq work iterator that will jump to each CPU with overloaded RT tasks. + * IRQ work iterator that will jump to each CPU with overloaded RT tasks. * As it only takes the first CPU that schedules a lower priority task * to start the process, the rto_start variable is incremented and if * the atomic result is one, then that CPU will try to take the rto_lock. @@ -2162,7 +2162,7 @@ static void push_rt_tasks(struct rq *rq) * CPUs scheduling lower priority tasks. * * All CPUs that are scheduling a lower priority task will increment the - * rt_loop_next variable. This will make sure that the irq work iterator + * rt_loop_next variable. This will make sure that the IRQ work iterator * checks all RT overloaded CPUs whenever a CPU schedules a new lower * priority task, even if the iterator is in the middle of a scan. Incrementing * the rt_loop_next will cause the iterator to perform another scan. @@ -2242,7 +2242,7 @@ static void tell_cpu_to_push(struct rq *rq) * The rto_cpu is updated under the lock, if it has a valid CPU * then the IPI is still running and will continue due to the * update to loop_next, and nothing needs to be done here. - * Otherwise it is finishing up and an ipi needs to be sent. + * Otherwise it is finishing up and an IPI needs to be sent. */ if (rq->rd->rto_cpu < 0) cpu = rto_next_cpu(rq->rd); @@ -2594,7 +2594,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) watchdog(rq, p); /* - * RR tasks need a special form of timeslice management. + * RR tasks need a special form of time-slice management. * FIFO tasks have no timeslices. */ if (p->policy != SCHED_RR) @@ -2900,7 +2900,7 @@ static int sched_rt_global_constraints(void) int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) { - /* Don't accept realtime tasks when there is no way for them to run */ + /* Don't accept real-time tasks when there is no way for them to run */ if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) return 0; @@ -3001,7 +3001,7 @@ static int sched_rr_handler(struct ctl_table *table, int write, void *buffer, ret = proc_dointvec(table, write, buffer, lenp, ppos); /* * Make sure that internally we keep jiffies. - * Also, writing zero resets the timeslice to default: + * Also, writing zero resets the time-slice to default: */ if (!ret && write) { sched_rr_timeslice = diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index ef20c61004eb..4c36cc680361 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -74,6 +74,12 @@ #include "../workqueue_internal.h" +struct rq; +struct cfs_rq; +struct rt_rq; +struct sched_group; +struct cpuidle_state; + #ifdef CONFIG_PARAVIRT # include <asm/paravirt.h> # include <asm/paravirt_api_clock.h> @@ -90,9 +96,6 @@ # define SCHED_WARN_ON(x) ({ (void)(x), 0; }) #endif -struct rq; -struct cpuidle_state; - /* task_struct::on_rq states: */ #define TASK_ON_RQ_QUEUED 1 #define TASK_ON_RQ_MIGRATING 2 @@ -128,12 +131,12 @@ extern struct list_head asym_cap_list; /* * Helpers for converting nanosecond timing to jiffy resolution */ -#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) +#define NS_TO_JIFFIES(time) ((unsigned long)(time) / (NSEC_PER_SEC/HZ)) /* * 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 + * low-weight task groups (eg. nice +19 on an autogroup), deeper task-group * hierarchies, especially on larger systems. This is not a user-visible change * and does not change the user-interface for setting shares/weights. * @@ -147,12 +150,13 @@ extern struct list_head asym_cap_list; #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; \ +# 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) @@ -187,6 +191,7 @@ static inline int idle_policy(int policy) { return policy == SCHED_IDLE; } + static inline int fair_policy(int policy) { return policy == SCHED_NORMAL || policy == SCHED_BATCH; @@ -201,6 +206,7 @@ static inline int dl_policy(int policy) { return policy == SCHED_DEADLINE; } + static inline bool valid_policy(int policy) { return idle_policy(policy) || fair_policy(policy) || @@ -222,11 +228,12 @@ static inline int task_has_dl_policy(struct task_struct *p) return dl_policy(p->policy); } -#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) +#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) static inline void update_avg(u64 *avg, u64 sample) { s64 diff = sample - *avg; + *avg += diff / 8; } @@ -251,7 +258,7 @@ static inline void update_avg(u64 *avg, u64 sample) */ #define SCHED_FLAG_SUGOV 0x10000000 -#define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) +#define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) static inline bool dl_entity_is_special(const struct sched_dl_entity *dl_se) { @@ -358,9 +365,6 @@ extern void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq, #ifdef CONFIG_CGROUP_SCHED -struct cfs_rq; -struct rt_rq; - extern struct list_head task_groups; struct cfs_bandwidth { @@ -406,7 +410,7 @@ struct task_group { #ifdef CONFIG_SMP /* * load_avg can be heavily contended at clock tick time, so put - * it in its own cacheline separated from the fields above which + * it in its own cache-line separated from the fields above which * will also be accessed at each tick. */ atomic_long_t load_avg ____cacheline_aligned; @@ -536,6 +540,7 @@ static inline void set_task_rq_fair(struct sched_entity *se, #else /* CONFIG_CGROUP_SCHED */ struct cfs_bandwidth { }; + static inline bool cfs_task_bw_constrained(struct task_struct *p) { return false; } #endif /* CONFIG_CGROUP_SCHED */ @@ -551,8 +556,8 @@ extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent * applicable for 32-bits architectures. */ #ifdef CONFIG_64BIT -# define u64_u32_load_copy(var, copy) var -# define u64_u32_store_copy(var, copy, val) (var = val) +# define u64_u32_load_copy(var, copy) var +# define u64_u32_store_copy(var, copy, val) (var = val) #else # define u64_u32_load_copy(var, copy) \ ({ \ @@ -580,8 +585,8 @@ do { \ copy = __val; \ } while (0) #endif -# define u64_u32_load(var) u64_u32_load_copy(var, var##_copy) -# define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val) +# define u64_u32_load(var) u64_u32_load_copy(var, var##_copy) +# define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val) /* CFS-related fields in a runqueue */ struct cfs_rq { @@ -803,6 +808,7 @@ struct dl_rq { }; #ifdef CONFIG_FAIR_GROUP_SCHED + /* An entity is a task if it doesn't "own" a runqueue */ #define entity_is_task(se) (!se->my_q) @@ -820,16 +826,18 @@ static inline long se_runnable(struct sched_entity *se) return se->runnable_weight; } -#else +#else /* !CONFIG_FAIR_GROUP_SCHED: */ + #define entity_is_task(se) 1 -static inline void se_update_runnable(struct sched_entity *se) {} +static inline void se_update_runnable(struct sched_entity *se) { } static inline long se_runnable(struct sched_entity *se) { return !!se->on_rq; } -#endif + +#endif /* !CONFIG_FAIR_GROUP_SCHED */ #ifdef CONFIG_SMP /* @@ -874,7 +882,7 @@ struct root_domain { */ bool overloaded; - /* Indicate one or more cpus over-utilized (tipping point) */ + /* Indicate one or more CPUs over-utilized (tipping point) */ bool overutilized; /* @@ -988,7 +996,6 @@ struct uclamp_rq { DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); #endif /* CONFIG_UCLAMP_TASK */ -struct rq; struct balance_callback { struct balance_callback *next; void (*func)(struct rq *rq); @@ -1144,7 +1151,7 @@ struct rq { call_single_data_t hrtick_csd; #endif struct hrtimer hrtick_timer; - ktime_t hrtick_time; + ktime_t hrtick_time; #endif #ifdef CONFIG_SCHEDSTATS @@ -1166,7 +1173,7 @@ struct rq { #endif #ifdef CONFIG_CPU_IDLE - /* Must be inspected within a rcu lock section */ + /* Must be inspected within a RCU lock section */ struct cpuidle_state *idle_state; #endif @@ -1228,7 +1235,7 @@ static inline int cpu_of(struct rq *rq) #endif } -#define MDF_PUSH 0x01 +#define MDF_PUSH 0x01 static inline bool is_migration_disabled(struct task_struct *p) { @@ -1247,7 +1254,6 @@ DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); #define cpu_curr(cpu) (cpu_rq(cpu)->curr) #define raw_rq() raw_cpu_ptr(&runqueues) -struct sched_group; #ifdef CONFIG_SCHED_CORE static inline struct cpumask *sched_group_span(struct sched_group *sg); @@ -1283,9 +1289,10 @@ static inline raw_spinlock_t *__rq_lockp(struct rq *rq) return &rq->__lock; } -bool cfs_prio_less(const struct task_struct *a, const struct task_struct *b, - bool fi); -void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); +extern bool +cfs_prio_less(const struct task_struct *a, const struct task_struct *b, bool fi); + +extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); /* * Helpers to check if the CPU's core cookie matches with the task's cookie @@ -1353,7 +1360,7 @@ extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags); extern void sched_core_get(void); extern void sched_core_put(void); -#else /* !CONFIG_SCHED_CORE */ +#else /* !CONFIG_SCHED_CORE: */ static inline bool sched_core_enabled(struct rq *rq) { @@ -1391,7 +1398,8 @@ static inline bool sched_group_cookie_match(struct rq *rq, { return true; } -#endif /* CONFIG_SCHED_CORE */ + +#endif /* !CONFIG_SCHED_CORE */ static inline void lockdep_assert_rq_held(struct rq *rq) { @@ -1422,8 +1430,10 @@ static inline void raw_spin_rq_unlock_irq(struct rq *rq) static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq) { unsigned long flags; + local_irq_save(flags); raw_spin_rq_lock(rq); + return flags; } @@ -1452,6 +1462,7 @@ static inline void update_idle_core(struct rq *rq) { } #endif #ifdef CONFIG_FAIR_GROUP_SCHED + static inline struct task_struct *task_of(struct sched_entity *se) { SCHED_WARN_ON(!entity_is_task(se)); @@ -1475,9 +1486,9 @@ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) return grp->my_q; } -#else +#else /* !CONFIG_FAIR_GROUP_SCHED: */ -#define task_of(_se) container_of(_se, struct task_struct, se) +#define task_of(_se) container_of(_se, struct task_struct, se) static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p) { @@ -1497,7 +1508,8 @@ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) { return NULL; } -#endif + +#endif /* !CONFIG_FAIR_GROUP_SCHED */ extern void update_rq_clock(struct rq *rq); @@ -1623,9 +1635,9 @@ static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) #ifdef CONFIG_SCHED_DEBUG rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); rf->clock_update_flags = 0; -#ifdef CONFIG_SMP +# ifdef CONFIG_SMP SCHED_WARN_ON(rq->balance_callback && rq->balance_callback != &balance_push_callback); -#endif +# endif #endif } @@ -1651,9 +1663,11 @@ static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) #endif } +extern struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires(rq->lock); +extern struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires(p->pi_lock) __acquires(rq->lock); @@ -1680,48 +1694,42 @@ DEFINE_LOCK_GUARD_1(task_rq_lock, struct task_struct, task_rq_unlock(_T->rq, _T->lock, &_T->rf), struct rq *rq; struct rq_flags rf) -static inline void -rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) +static inline void rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { raw_spin_rq_lock_irqsave(rq, rf->flags); rq_pin_lock(rq, rf); } -static inline void -rq_lock_irq(struct rq *rq, struct rq_flags *rf) +static inline void rq_lock_irq(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { raw_spin_rq_lock_irq(rq); rq_pin_lock(rq, rf); } -static inline void -rq_lock(struct rq *rq, struct rq_flags *rf) +static inline void rq_lock(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { raw_spin_rq_lock(rq); rq_pin_lock(rq, rf); } -static inline void -rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) +static inline void rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); raw_spin_rq_unlock_irqrestore(rq, rf->flags); } -static inline void -rq_unlock_irq(struct rq *rq, struct rq_flags *rf) +static inline void rq_unlock_irq(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); raw_spin_rq_unlock_irq(rq); } -static inline void -rq_unlock(struct rq *rq, struct rq_flags *rf) +static inline void rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); @@ -1743,8 +1751,7 @@ DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq, rq_unlock_irqrestore(_T->lock, &_T->rf), struct rq_flags rf) -static inline struct rq * -this_rq_lock_irq(struct rq_flags *rf) +static inline struct rq *this_rq_lock_irq(struct rq_flags *rf) __acquires(rq->lock) { struct rq *rq; @@ -1752,15 +1759,18 @@ this_rq_lock_irq(struct rq_flags *rf) local_irq_disable(); rq = this_rq(); rq_lock(rq, rf); + return rq; } #ifdef CONFIG_NUMA + enum numa_topology_type { NUMA_DIRECT, NUMA_GLUELESS_MESH, NUMA_BACKPLANE, }; + extern enum numa_topology_type sched_numa_topology_type; extern int sched_max_numa_distance; extern bool find_numa_distance(int distance); @@ -1769,18 +1779,23 @@ extern void sched_update_numa(int cpu, bool online); extern void sched_domains_numa_masks_set(unsigned int cpu); extern void sched_domains_numa_masks_clear(unsigned int cpu); extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); -#else + +#else /* !CONFIG_NUMA: */ + static inline void sched_init_numa(int offline_node) { } static inline void sched_update_numa(int cpu, bool online) { } static inline void sched_domains_numa_masks_set(unsigned int cpu) { } static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } + static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) { return nr_cpu_ids; } -#endif + +#endif /* !CONFIG_NUMA */ #ifdef CONFIG_NUMA_BALANCING + /* The regions in numa_faults array from task_struct */ enum numa_faults_stats { NUMA_MEM = 0, @@ -1788,17 +1803,21 @@ enum numa_faults_stats { NUMA_MEMBUF, NUMA_CPUBUF }; + extern void sched_setnuma(struct task_struct *p, int node); extern int migrate_task_to(struct task_struct *p, int cpu); extern int migrate_swap(struct task_struct *p, struct task_struct *t, int cpu, int scpu); extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p); -#else + +#else /* !CONFIG_NUMA_BALANCING: */ + static inline void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) { } -#endif /* CONFIG_NUMA_BALANCING */ + +#endif /* !CONFIG_NUMA_BALANCING */ #ifdef CONFIG_SMP @@ -1823,8 +1842,7 @@ queue_balance_callback(struct rq *rq, } #define rcu_dereference_check_sched_domain(p) \ - rcu_dereference_check((p), \ - lockdep_is_held(&sched_domains_mutex)) + rcu_dereference_check((p), lockdep_is_held(&sched_domains_mutex)) /* * The domain tree (rq->sd) is protected by RCU's quiescent state transition. @@ -1895,6 +1913,7 @@ DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); + extern struct static_key_false sched_asym_cpucapacity; extern struct static_key_false sched_cluster_active; @@ -1958,15 +1977,11 @@ static inline struct cpumask *group_balance_mask(struct sched_group *sg) extern int group_balance_cpu(struct sched_group *sg); #ifdef CONFIG_SCHED_DEBUG -void update_sched_domain_debugfs(void); -void dirty_sched_domain_sysctl(int cpu); +extern void update_sched_domain_debugfs(void); +extern void dirty_sched_domain_sysctl(int cpu); #else -static inline void update_sched_domain_debugfs(void) -{ -} -static inline void dirty_sched_domain_sysctl(int cpu) -{ -} +static inline void update_sched_domain_debugfs(void) { } +static inline void dirty_sched_domain_sysctl(int cpu) { } #endif extern int sched_update_scaling(void); @@ -1977,6 +1992,7 @@ static inline const struct cpumask *task_user_cpus(struct task_struct *p) return cpu_possible_mask; /* &init_task.cpus_mask */ return p->user_cpus_ptr; } + #endif /* CONFIG_SMP */ #include "stats.h" @@ -1999,13 +2015,13 @@ static inline void sched_core_tick(struct rq *rq) __sched_core_tick(rq); } -#else +#else /* !(CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS): */ -static inline void sched_core_account_forceidle(struct rq *rq) {} +static inline void sched_core_account_forceidle(struct rq *rq) { } -static inline void sched_core_tick(struct rq *rq) {} +static inline void sched_core_tick(struct rq *rq) { } -#endif /* CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS */ +#endif /* !(CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS) */ #ifdef CONFIG_CGROUP_SCHED @@ -2047,15 +2063,16 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) #endif } -#else /* CONFIG_CGROUP_SCHED */ +#else /* !CONFIG_CGROUP_SCHED: */ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } + static inline struct task_group *task_group(struct task_struct *p) { return NULL; } -#endif /* CONFIG_CGROUP_SCHED */ +#endif /* !CONFIG_CGROUP_SCHED */ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) { @@ -2100,6 +2117,7 @@ enum { extern const_debug unsigned int sysctl_sched_features; #ifdef CONFIG_JUMP_LABEL + #define SCHED_FEAT(name, enabled) \ static __always_inline bool static_branch_##name(struct static_key *key) \ { \ @@ -2112,13 +2130,13 @@ static __always_inline bool static_branch_##name(struct static_key *key) \ extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) -#else /* !CONFIG_JUMP_LABEL */ +#else /* !CONFIG_JUMP_LABEL: */ #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) -#endif /* CONFIG_JUMP_LABEL */ +#endif /* !CONFIG_JUMP_LABEL */ -#else /* !SCHED_DEBUG */ +#else /* !SCHED_DEBUG: */ /* * Each translation unit has its own copy of sysctl_sched_features to allow @@ -2134,7 +2152,7 @@ static const_debug __maybe_unused unsigned int sysctl_sched_features = #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) -#endif /* SCHED_DEBUG */ +#endif /* !SCHED_DEBUG */ extern struct static_key_false sched_numa_balancing; extern struct static_key_false sched_schedstats; @@ -2177,13 +2195,13 @@ static inline int task_on_rq_migrating(struct task_struct *p) } /* Wake flags. The first three directly map to some SD flag value */ -#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ -#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ -#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ +#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ +#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ +#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ -#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ -#define WF_MIGRATED 0x20 /* Internal use, task got migrated */ -#define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ +#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ +#define WF_MIGRATED 0x20 /* Internal use, task got migrated */ +#define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ #ifdef CONFIG_SMP static_assert(WF_EXEC == SD_BALANCE_EXEC); @@ -2253,9 +2271,9 @@ extern const u32 sched_prio_to_wmult[40]; #define RETRY_TASK ((void *)-1UL) struct affinity_context { - const struct cpumask *new_mask; - struct cpumask *user_mask; - unsigned int flags; + const struct cpumask *new_mask; + struct cpumask *user_mask; + unsigned int flags; }; extern s64 update_curr_common(struct rq *rq); @@ -2403,8 +2421,19 @@ extern void update_group_capacity(struct sched_domain *sd, int cpu); extern void sched_balance_trigger(struct rq *rq); +extern int __set_cpus_allowed_ptr(struct task_struct *p, struct affinity_context *ctx); extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx); +static inline cpumask_t *alloc_user_cpus_ptr(int node) +{ + /* + * See do_set_cpus_allowed() above for the rcu_head usage. + */ + int size = max_t(int, cpumask_size(), sizeof(struct rcu_head)); + + return kmalloc_node(size, GFP_KERNEL, node); +} + static inline struct task_struct *get_push_task(struct rq *rq) { struct task_struct *p = rq->curr; @@ -2426,9 +2455,23 @@ static inline struct task_struct *get_push_task(struct rq *rq) extern int push_cpu_stop(void *arg); -#endif +#else /* !CONFIG_SMP: */ + +static inline int __set_cpus_allowed_ptr(struct task_struct *p, + struct affinity_context *ctx) +{ + return set_cpus_allowed_ptr(p, ctx->new_mask); +} + +static inline cpumask_t *alloc_user_cpus_ptr(int node) +{ + return NULL; +} + +#endif /* !CONFIG_SMP */ #ifdef CONFIG_CPU_IDLE + static inline void idle_set_state(struct rq *rq, struct cpuidle_state *idle_state) { @@ -2441,7 +2484,9 @@ static inline struct cpuidle_state *idle_get_state(struct rq *rq) return rq->idle_state; } -#else + +#else /* !CONFIG_CPU_IDLE: */ + static inline void idle_set_state(struct rq *rq, struct cpuidle_state *idle_state) { @@ -2451,7 +2496,8 @@ static inline struct cpuidle_state *idle_get_state(struct rq *rq) { return NULL; } -#endif + +#endif /* !CONFIG_CPU_IDLE */ extern void schedule_idle(void); asmlinkage void schedule_user(void); @@ -2464,7 +2510,7 @@ extern void init_sched_dl_class(void); extern void init_sched_rt_class(void); extern void init_sched_fair_class(void); -extern void reweight_task(struct task_struct *p, int prio); +extern void reweight_task(struct task_struct *p, const struct load_weight *lw); extern void resched_curr(struct rq *rq); extern void resched_cpu(int cpu); @@ -2480,7 +2526,8 @@ extern void init_dl_entity(struct sched_dl_entity *dl_se); #define RATIO_SHIFT 8 #define MAX_BW_BITS (64 - BW_SHIFT) #define MAX_BW ((1ULL << MAX_BW_BITS) - 1) -unsigned long to_ratio(u64 period, u64 runtime); + +extern unsigned long to_ratio(u64 period, u64 runtime); extern void init_entity_runnable_average(struct sched_entity *se); extern void post_init_entity_util_avg(struct task_struct *p); @@ -2506,10 +2553,10 @@ static inline void sched_update_tick_dependency(struct rq *rq) else tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); } -#else +#else /* !CONFIG_NO_HZ_FULL: */ static inline int sched_tick_offload_init(void) { return 0; } static inline void sched_update_tick_dependency(struct rq *rq) { } -#endif +#endif /* !CONFIG_NO_HZ_FULL */ static inline void add_nr_running(struct rq *rq, unsigned count) { @@ -2545,9 +2592,9 @@ extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); extern void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags); #ifdef CONFIG_PREEMPT_RT -#define SCHED_NR_MIGRATE_BREAK 8 +# define SCHED_NR_MIGRATE_BREAK 8 #else -#define SCHED_NR_MIGRATE_BREAK 32 +# define SCHED_NR_MIGRATE_BREAK 32 #endif extern const_debug unsigned int sysctl_sched_nr_migrate; @@ -2596,9 +2643,9 @@ static inline int hrtick_enabled_dl(struct rq *rq) return hrtick_enabled(rq); } -void hrtick_start(struct rq *rq, u64 delay); +extern void hrtick_start(struct rq *rq, u64 delay); -#else +#else /* !CONFIG_SCHED_HRTICK: */ static inline int hrtick_enabled_fair(struct rq *rq) { @@ -2615,13 +2662,10 @@ static inline int hrtick_enabled(struct rq *rq) return 0; } -#endif /* CONFIG_SCHED_HRTICK */ +#endif /* !CONFIG_SCHED_HRTICK */ #ifndef arch_scale_freq_tick -static __always_inline -void arch_scale_freq_tick(void) -{ -} +static __always_inline void arch_scale_freq_tick(void) { } #endif #ifndef arch_scale_freq_capacity @@ -2658,13 +2702,13 @@ static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) #endif } #else -static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) {} +static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) { } #endif -#define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...) \ -__DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__) \ -static inline class_##name##_t class_##name##_constructor(type *lock, type *lock2) \ -{ class_##name##_t _t = { .lock = lock, .lock2 = lock2 }, *_T = &_t; \ +#define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...) \ +__DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__) \ +static inline class_##name##_t class_##name##_constructor(type *lock, type *lock2) \ +{ class_##name##_t _t = { .lock = lock, .lock2 = lock2 }, *_T = &_t; \ _lock; return _t; } #ifdef CONFIG_SMP @@ -2718,7 +2762,7 @@ static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) return 1; } -#else +#else /* !CONFIG_PREEMPTION: */ /* * Unfair double_lock_balance: Optimizes throughput at the expense of * latency by eliminating extra atomic operations when the locks are @@ -2749,7 +2793,7 @@ static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) return 1; } -#endif /* CONFIG_PREEMPTION */ +#endif /* !CONFIG_PREEMPTION */ /* * double_lock_balance - lock the busiest runqueue, this_rq is locked already. @@ -2825,9 +2869,10 @@ static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) extern void set_rq_online (struct rq *rq); extern void set_rq_offline(struct rq *rq); + extern bool sched_smp_initialized; -#else /* CONFIG_SMP */ +#else /* !CONFIG_SMP: */ /* * double_rq_lock - safely lock two runqueues @@ -2861,7 +2906,7 @@ static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) __release(rq2->lock); } -#endif +#endif /* !CONFIG_SMP */ DEFINE_LOCK_GUARD_2(double_rq_lock, struct rq, double_rq_lock(_T->lock, _T->lock2), @@ -2882,16 +2927,15 @@ extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); extern void resched_latency_warn(int cpu, u64 latency); -#ifdef CONFIG_NUMA_BALANCING -extern void -show_numa_stats(struct task_struct *p, struct seq_file *m); +# ifdef CONFIG_NUMA_BALANCING +extern void show_numa_stats(struct task_struct *p, struct seq_file *m); extern void print_numa_stats(struct seq_file *m, int node, unsigned long tsf, - unsigned long tpf, unsigned long gsf, unsigned long gpf); -#endif /* CONFIG_NUMA_BALANCING */ -#else -static inline void resched_latency_warn(int cpu, u64 latency) {} -#endif /* CONFIG_SCHED_DEBUG */ + unsigned long tpf, unsigned long gsf, unsigned long gpf); +# endif /* CONFIG_NUMA_BALANCING */ +#else /* !CONFIG_SCHED_DEBUG: */ +static inline void resched_latency_warn(int cpu, u64 latency) { } +#endif /* !CONFIG_SCHED_DEBUG */ extern void init_cfs_rq(struct cfs_rq *cfs_rq); extern void init_rt_rq(struct rt_rq *rt_rq); @@ -2901,6 +2945,7 @@ extern void cfs_bandwidth_usage_inc(void); extern void cfs_bandwidth_usage_dec(void); #ifdef CONFIG_NO_HZ_COMMON + #define NOHZ_BALANCE_KICK_BIT 0 #define NOHZ_STATS_KICK_BIT 1 #define NOHZ_NEWILB_KICK_BIT 2 @@ -2915,14 +2960,14 @@ extern void cfs_bandwidth_usage_dec(void); /* Update nohz.next_balance */ #define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT) -#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) +#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) -#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) +#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) extern void nohz_balance_exit_idle(struct rq *rq); -#else +#else /* !CONFIG_NO_HZ_COMMON: */ static inline void nohz_balance_exit_idle(struct rq *rq) { } -#endif +#endif /* !CONFIG_NO_HZ_COMMON */ #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) extern void nohz_run_idle_balance(int cpu); @@ -2931,6 +2976,7 @@ static inline void nohz_run_idle_balance(int cpu) { } #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING + struct irqtime { u64 total; u64 tick_delta; @@ -2958,9 +3004,11 @@ static inline u64 irq_time_read(int cpu) return total; } + #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ #ifdef CONFIG_CPU_FREQ + DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); /** @@ -2994,9 +3042,9 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 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 */ +#else /* !CONFIG_CPU_FREQ: */ +static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) { } +#endif /* !CONFIG_CPU_FREQ */ #ifdef arch_scale_freq_capacity # ifndef arch_scale_freq_invariant @@ -3007,6 +3055,7 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} #endif #ifdef CONFIG_SMP + unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, unsigned long *min, unsigned long *max); @@ -3049,9 +3098,11 @@ static inline unsigned long cpu_util_rt(struct rq *rq) { return READ_ONCE(rq->avg_rt.util_avg); } -#endif + +#endif /* CONFIG_SMP */ #ifdef CONFIG_UCLAMP_TASK + unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); static inline unsigned long uclamp_rq_get(struct rq *rq, @@ -3098,9 +3149,40 @@ static inline bool uclamp_is_used(void) { return static_branch_likely(&sched_uclamp_used); } -#else /* CONFIG_UCLAMP_TASK */ -static inline unsigned long uclamp_eff_value(struct task_struct *p, - enum uclamp_id clamp_id) + +#define for_each_clamp_id(clamp_id) \ + for ((clamp_id) = 0; (clamp_id) < UCLAMP_CNT; (clamp_id)++) + +extern unsigned int sysctl_sched_uclamp_util_min_rt_default; + + +static inline unsigned int uclamp_none(enum uclamp_id clamp_id) +{ + if (clamp_id == UCLAMP_MIN) + return 0; + return SCHED_CAPACITY_SCALE; +} + +/* Integer rounded range for each bucket */ +#define UCLAMP_BUCKET_DELTA DIV_ROUND_CLOSEST(SCHED_CAPACITY_SCALE, UCLAMP_BUCKETS) + +static inline unsigned int uclamp_bucket_id(unsigned int clamp_value) +{ + return min_t(unsigned int, clamp_value / UCLAMP_BUCKET_DELTA, UCLAMP_BUCKETS - 1); +} + +static inline void +uclamp_se_set(struct uclamp_se *uc_se, unsigned int value, bool user_defined) +{ + uc_se->value = value; + uc_se->bucket_id = uclamp_bucket_id(value); + uc_se->user_defined = user_defined; +} + +#else /* !CONFIG_UCLAMP_TASK: */ + +static inline unsigned long +uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id) { if (clamp_id == UCLAMP_MIN) return 0; @@ -3115,8 +3197,8 @@ static inline bool uclamp_is_used(void) return false; } -static inline unsigned long uclamp_rq_get(struct rq *rq, - enum uclamp_id clamp_id) +static inline unsigned long +uclamp_rq_get(struct rq *rq, enum uclamp_id clamp_id) { if (clamp_id == UCLAMP_MIN) return 0; @@ -3124,8 +3206,8 @@ static inline unsigned long uclamp_rq_get(struct rq *rq, return SCHED_CAPACITY_SCALE; } -static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, - unsigned int value) +static inline void +uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, unsigned int value) { } @@ -3133,9 +3215,11 @@ static inline bool uclamp_rq_is_idle(struct rq *rq) { return false; } -#endif /* CONFIG_UCLAMP_TASK */ + +#endif /* !CONFIG_UCLAMP_TASK */ #ifdef CONFIG_HAVE_SCHED_AVG_IRQ + static inline unsigned long cpu_util_irq(struct rq *rq) { return READ_ONCE(rq->avg_irq.util_avg); @@ -3150,7 +3234,9 @@ unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned return util; } -#else + +#else /* !CONFIG_HAVE_SCHED_AVG_IRQ: */ + static inline unsigned long cpu_util_irq(struct rq *rq) { return 0; @@ -3161,7 +3247,8 @@ unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned { return util; } -#endif + +#endif /* !CONFIG_HAVE_SCHED_AVG_IRQ */ #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) @@ -3179,11 +3266,13 @@ extern struct cpufreq_governor schedutil_gov; #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ #define perf_domain_span(pd) NULL + static inline bool sched_energy_enabled(void) { return false; } #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ #ifdef CONFIG_MEMBARRIER + /* * The scheduler provides memory barriers required by membarrier between: * - prior user-space memory accesses and store to rq->membarrier_state, @@ -3205,13 +3294,16 @@ static inline void membarrier_switch_mm(struct rq *rq, WRITE_ONCE(rq->membarrier_state, membarrier_state); } -#else + +#else /* !CONFIG_MEMBARRIER :*/ + static inline void membarrier_switch_mm(struct rq *rq, struct mm_struct *prev_mm, struct mm_struct *next_mm) { } -#endif + +#endif /* !CONFIG_MEMBARRIER */ #ifdef CONFIG_SMP static inline bool is_per_cpu_kthread(struct task_struct *p) @@ -3263,7 +3355,7 @@ static inline void __mm_cid_put(struct mm_struct *mm, int cid) * be held to transition to other states. * * State transitions synchronized with cmpxchg or try_cmpxchg need to be - * consistent across cpus, which prevents use of this_cpu_cmpxchg. + * consistent across CPUs, which prevents use of this_cpu_cmpxchg. */ static inline void mm_cid_put_lazy(struct task_struct *t) { @@ -3330,6 +3422,7 @@ static inline int __mm_cid_try_get(struct mm_struct *mm) } if (cpumask_test_and_set_cpu(cid, cpumask)) return -1; + return cid; } @@ -3394,6 +3487,7 @@ unlock: raw_spin_unlock(&cid_lock); end: mm_cid_snapshot_time(rq, mm); + return cid; } @@ -3416,6 +3510,7 @@ static inline int mm_cid_get(struct rq *rq, struct mm_struct *mm) } cid = __mm_cid_get(rq, mm); __this_cpu_write(pcpu_cid->cid, cid); + return cid; } @@ -3470,15 +3565,68 @@ static inline void switch_mm_cid(struct rq *rq, next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next->mm); } -#else +#else /* !CONFIG_SCHED_MM_CID: */ static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { } static inline void sched_mm_cid_migrate_from(struct task_struct *t) { } static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) { } static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { } static inline void init_sched_mm_cid(struct task_struct *t) { } -#endif +#endif /* !CONFIG_SCHED_MM_CID */ extern u64 avg_vruntime(struct cfs_rq *cfs_rq); extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se); +#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); +} + +#else /* !CONFIG_RT_MUTEXES: */ + +static inline int rt_effective_prio(struct task_struct *p, int prio) +{ + return prio; +} + +#endif /* !CONFIG_RT_MUTEXES */ + +extern int __sched_setscheduler(struct task_struct *p, const struct sched_attr *attr, bool user, bool pi); +extern int __sched_setaffinity(struct task_struct *p, struct affinity_context *ctx); +extern void __setscheduler_prio(struct task_struct *p, int prio); +extern void set_load_weight(struct task_struct *p, bool update_load); +extern void enqueue_task(struct rq *rq, struct task_struct *p, int flags); +extern void dequeue_task(struct rq *rq, struct task_struct *p, int flags); + +extern void check_class_changed(struct rq *rq, struct task_struct *p, + const struct sched_class *prev_class, + int oldprio); + +#ifdef CONFIG_SMP +extern struct balance_callback *splice_balance_callbacks(struct rq *rq); +extern void balance_callbacks(struct rq *rq, struct balance_callback *head); +#else + +static inline struct balance_callback *splice_balance_callbacks(struct rq *rq) +{ + return NULL; +} + +static inline void balance_callbacks(struct rq *rq, struct balance_callback *head) +{ +} + +#endif + #endif /* _KERNEL_SCHED_SCHED_H */ diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h index b02dfc322951..237780aa3c53 100644 --- a/kernel/sched/stats.h +++ b/kernel/sched/stats.h @@ -224,7 +224,7 @@ static inline void sched_info_dequeue(struct rq *rq, struct task_struct *t) /* * Called when a task finally hits the CPU. We can now calculate how * long it was waiting to run. We also note when it began so that we - * can keep stats on how long its timeslice is. + * can keep stats on how long its time-slice is. */ static void sched_info_arrive(struct rq *rq, struct task_struct *t) { diff --git a/kernel/sched/syscalls.c b/kernel/sched/syscalls.c new file mode 100644 index 000000000000..ae1b42775ef9 --- /dev/null +++ b/kernel/sched/syscalls.c @@ -0,0 +1,1699 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * kernel/sched/syscalls.c + * + * Core kernel scheduler syscalls related code + * + * Copyright (C) 1991-2002 Linus Torvalds + * Copyright (C) 1998-2024 Ingo Molnar, Red Hat + */ +#include <linux/sched.h> +#include <linux/cpuset.h> +#include <linux/sched/debug.h> + +#include <uapi/linux/sched/types.h> + +#include "sched.h" +#include "autogroup.h" + +static inline int __normal_prio(int policy, int rt_prio, int nice) +{ + int prio; + + if (dl_policy(policy)) + prio = MAX_DL_PRIO - 1; + else if (rt_policy(policy)) + prio = MAX_RT_PRIO - 1 - rt_prio; + else + prio = NICE_TO_PRIO(nice); + + return prio; +} + +/* + * Calculate the expected normal priority: i.e. priority + * without taking RT-inheritance into account. Might be + * boosted by interactivity modifiers. Changes upon fork, + * setprio syscalls, and whenever the interactivity + * estimator recalculates. + */ +static inline int normal_prio(struct task_struct *p) +{ + return __normal_prio(p->policy, p->rt_priority, PRIO_TO_NICE(p->static_prio)); +} + +/* + * Calculate the current priority, i.e. the priority + * taken into account by the scheduler. This value might + * be boosted by RT tasks, or might be boosted by + * interactivity modifiers. 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; +} + +void set_user_nice(struct task_struct *p, long nice) +{ + bool queued, running; + struct rq *rq; + int old_prio; + + 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. + */ + CLASS(task_rq_lock, rq_guard)(p); + rq = rq_guard.rq; + + update_rq_clock(rq); + + /* + * 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 + * SCHED_DEADLINE, SCHED_FIFO or SCHED_RR: + */ + if (task_has_dl_policy(p) || task_has_rt_policy(p)) { + p->static_prio = NICE_TO_PRIO(nice); + return; + } + + queued = task_on_rq_queued(p); + running = task_current(rq, p); + if (queued) + dequeue_task(rq, p, DEQUEUE_SAVE | DEQUEUE_NOCLOCK); + if (running) + put_prev_task(rq, p); + + p->static_prio = NICE_TO_PRIO(nice); + set_load_weight(p, true); + old_prio = p->prio; + p->prio = effective_prio(p); + + if (queued) + enqueue_task(rq, p, ENQUEUE_RESTORE | ENQUEUE_NOCLOCK); + if (running) + set_next_task(rq, p); + + /* + * If the task increased its priority or is running and + * lowered its priority, then reschedule its CPU: + */ + p->sched_class->prio_changed(rq, p, old_prio); +} +EXPORT_SYMBOL(set_user_nice); + +/* + * is_nice_reduction - check if nice value is an actual reduction + * + * Similar to can_nice() but does not perform a capability check. + * + * @p: task + * @nice: nice value + */ +static bool is_nice_reduction(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)); +} + +/* + * 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) +{ + return is_nice_reduction(p, 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 + +/** + * 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 ... 139] 0/[-20 ... 19] + * fifo, rr [-2 ... -100] [98 ... 0] [1 ... 99] + * deadline -101 -1 0 + */ +int task_prio(const struct task_struct *p) +{ + return p->prio - MAX_RT_PRIO; +} + +/** + * 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; +} + +/** + * available_idle_cpu - is a given CPU idle for enqueuing work. + * @cpu: the CPU in question. + * + * Return: 1 if the CPU is currently idle. 0 otherwise. + */ +int available_idle_cpu(int cpu) +{ + if (!idle_cpu(cpu)) + return 0; + + if (vcpu_is_preempted(cpu)) + return 0; + + 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; +} + +#ifdef CONFIG_SCHED_CORE +int sched_core_idle_cpu(int cpu) +{ + struct rq *rq = cpu_rq(cpu); + + if (sched_core_enabled(rq) && rq->curr == rq->idle) + return 1; + + return idle_cpu(cpu); +} + +#endif + +#ifdef CONFIG_SMP +/* + * This function computes an effective utilization for the given CPU, to be + * used for frequency selection given the linear relation: f = u * f_max. + * + * The scheduler tracks the following metrics: + * + * cpu_util_{cfs,rt,dl,irq}() + * cpu_bw_dl() + * + * Where the cfs,rt and dl util numbers are tracked with the same metric and + * synchronized windows and are thus directly comparable. + * + * The cfs,rt,dl utilization are the running times measured with rq->clock_task + * which excludes things like IRQ and steal-time. These latter are then accrued + * in the IRQ utilization. + * + * The DL bandwidth number OTOH is not a measured metric but a value computed + * based on the task model parameters and gives the minimal utilization + * required to meet deadlines. + */ +unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, + unsigned long *min, + unsigned long *max) +{ + unsigned long util, irq, scale; + struct rq *rq = cpu_rq(cpu); + + scale = arch_scale_cpu_capacity(cpu); + + /* + * Early check to see if IRQ/steal time saturates the CPU, can be + * because of inaccuracies in how we track these -- see + * update_irq_load_avg(). + */ + irq = cpu_util_irq(rq); + if (unlikely(irq >= scale)) { + if (min) + *min = scale; + if (max) + *max = scale; + return scale; + } + + if (min) { + /* + * The minimum utilization returns the highest level between: + * - the computed DL bandwidth needed with the IRQ pressure which + * steals time to the deadline task. + * - The minimum performance requirement for CFS and/or RT. + */ + *min = max(irq + cpu_bw_dl(rq), uclamp_rq_get(rq, UCLAMP_MIN)); + + /* + * When an RT task is runnable and uclamp is not used, we must + * ensure that the task will run at maximum compute capacity. + */ + if (!uclamp_is_used() && rt_rq_is_runnable(&rq->rt)) + *min = max(*min, scale); + } + + /* + * Because the time spend on RT/DL tasks is visible as 'lost' time to + * CFS tasks and we use the same metric to track the effective + * utilization (PELT windows are synchronized) we can directly add them + * to obtain the CPU's actual utilization. + */ + util = util_cfs + cpu_util_rt(rq); + util += cpu_util_dl(rq); + + /* + * The maximum hint is a soft bandwidth requirement, which can be lower + * than the actual utilization because of uclamp_max requirements. + */ + if (max) + *max = min(scale, uclamp_rq_get(rq, UCLAMP_MAX)); + + if (util >= scale) + return scale; + + /* + * There is still idle time; further improve the number by using the + * IRQ metric. Because IRQ/steal time is hidden from the task clock we + * need to scale the task numbers: + * + * max - irq + * U' = irq + --------- * U + * max + */ + util = scale_irq_capacity(util, irq, scale); + util += irq; + + return min(scale, util); +} + +unsigned long sched_cpu_util(int cpu) +{ + return effective_cpu_util(cpu, cpu_util_cfs(cpu), NULL, NULL); +} +#endif /* CONFIG_SMP */ + +/** + * 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 struct task_struct *find_process_by_pid(pid_t pid) +{ + return pid ? find_task_by_vpid(pid) : current; +} + +static struct task_struct *find_get_task(pid_t pid) +{ + struct task_struct *p; + guard(rcu)(); + + p = find_process_by_pid(pid); + if (likely(p)) + get_task_struct(p); + + return p; +} + +DEFINE_CLASS(find_get_task, struct task_struct *, if (_T) put_task_struct(_T), + find_get_task(pid), pid_t pid) + +/* + * 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; + + if (dl_policy(policy)) + __setparam_dl(p, attr); + else if (fair_policy(policy)) + 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); + set_load_weight(p, true); +} + +/* + * 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; + guard(rcu)(); + + pcred = __task_cred(p); + return (uid_eq(cred->euid, pcred->euid) || + uid_eq(cred->euid, pcred->uid)); +} + +#ifdef CONFIG_UCLAMP_TASK + +static int uclamp_validate(struct task_struct *p, + const struct sched_attr *attr) +{ + int util_min = p->uclamp_req[UCLAMP_MIN].value; + int util_max = p->uclamp_req[UCLAMP_MAX].value; + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { + util_min = attr->sched_util_min; + + if (util_min + 1 > SCHED_CAPACITY_SCALE + 1) + return -EINVAL; + } + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { + util_max = attr->sched_util_max; + + if (util_max + 1 > SCHED_CAPACITY_SCALE + 1) + return -EINVAL; + } + + if (util_min != -1 && util_max != -1 && util_min > util_max) + return -EINVAL; + + /* + * We have valid uclamp attributes; make sure uclamp is enabled. + * + * We need to do that here, because enabling static branches is a + * blocking operation which obviously cannot be done while holding + * scheduler locks. + */ + static_branch_enable(&sched_uclamp_used); + + return 0; +} + +static bool uclamp_reset(const struct sched_attr *attr, + enum uclamp_id clamp_id, + struct uclamp_se *uc_se) +{ + /* Reset on sched class change for a non user-defined clamp value. */ + if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP)) && + !uc_se->user_defined) + return true; + + /* Reset on sched_util_{min,max} == -1. */ + if (clamp_id == UCLAMP_MIN && + attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN && + attr->sched_util_min == -1) { + return true; + } + + if (clamp_id == UCLAMP_MAX && + attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX && + attr->sched_util_max == -1) { + return true; + } + + return false; +} + +static void __setscheduler_uclamp(struct task_struct *p, + const struct sched_attr *attr) +{ + enum uclamp_id clamp_id; + + for_each_clamp_id(clamp_id) { + struct uclamp_se *uc_se = &p->uclamp_req[clamp_id]; + unsigned int value; + + if (!uclamp_reset(attr, clamp_id, uc_se)) + continue; + + /* + * RT by default have a 100% boost value that could be modified + * at runtime. + */ + if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN)) + value = sysctl_sched_uclamp_util_min_rt_default; + else + value = uclamp_none(clamp_id); + + uclamp_se_set(uc_se, value, false); + + } + + if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP))) + return; + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN && + attr->sched_util_min != -1) { + uclamp_se_set(&p->uclamp_req[UCLAMP_MIN], + attr->sched_util_min, true); + } + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX && + attr->sched_util_max != -1) { + uclamp_se_set(&p->uclamp_req[UCLAMP_MAX], + attr->sched_util_max, true); + } +} + +#else /* !CONFIG_UCLAMP_TASK: */ + +static inline int uclamp_validate(struct task_struct *p, + const struct sched_attr *attr) +{ + return -EOPNOTSUPP; +} +static void __setscheduler_uclamp(struct task_struct *p, + const struct sched_attr *attr) { } +#endif + +/* + * Allow unprivileged RT tasks to decrease priority. + * Only issue a capable test if needed and only once to avoid an audit + * event on permitted non-privileged operations: + */ +static int user_check_sched_setscheduler(struct task_struct *p, + const struct sched_attr *attr, + int policy, int reset_on_fork) +{ + if (fair_policy(policy)) { + if (attr->sched_nice < task_nice(p) && + !is_nice_reduction(p, attr->sched_nice)) + goto req_priv; + } + + if (rt_policy(policy)) { + unsigned long rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); + + /* Can't set/change the rt policy: */ + if (policy != p->policy && !rlim_rtprio) + goto req_priv; + + /* Can't increase priority: */ + if (attr->sched_priority > p->rt_priority && + attr->sched_priority > rlim_rtprio) + goto req_priv; + } + + /* + * Can't set/change SCHED_DEADLINE policy at all for now + * (safest behavior); in the future we would like to allow + * unprivileged DL tasks to increase their relative deadline + * or reduce their runtime (both ways reducing utilization) + */ + if (dl_policy(policy)) + goto req_priv; + + /* + * Treat SCHED_IDLE as nice 20. Only allow a switch to + * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. + */ + if (task_has_idle_policy(p) && !idle_policy(policy)) { + if (!is_nice_reduction(p, task_nice(p))) + goto req_priv; + } + + /* Can't change other user's priorities: */ + if (!check_same_owner(p)) + goto req_priv; + + /* Normal users shall not reset the sched_reset_on_fork flag: */ + if (p->sched_reset_on_fork && !reset_on_fork) + goto req_priv; + + return 0; + +req_priv: + if (!capable(CAP_SYS_NICE)) + return -EPERM; + + return 0; +} + +int __sched_setscheduler(struct task_struct *p, + const struct sched_attr *attr, + bool user, bool pi) +{ + int oldpolicy = -1, policy = attr->sched_policy; + int retval, oldprio, newprio, queued, running; + const struct sched_class *prev_class; + struct balance_callback *head; + struct rq_flags rf; + int reset_on_fork; + int queue_flags = DEQUEUE_SAVE | DEQUEUE_MOVE | DEQUEUE_NOCLOCK; + struct rq *rq; + bool cpuset_locked = false; + + /* The pi code expects interrupts enabled */ + BUG_ON(pi && in_interrupt()); +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_FLAG_RESET_ON_FORK); + + if (!valid_policy(policy)) + return -EINVAL; + } + + if (attr->sched_flags & ~(SCHED_FLAG_ALL | SCHED_FLAG_SUGOV)) + return -EINVAL; + + /* + * Valid priorities for SCHED_FIFO and SCHED_RR are + * 1..MAX_RT_PRIO-1, valid priority for SCHED_NORMAL, + * SCHED_BATCH and SCHED_IDLE is 0. + */ + if (attr->sched_priority > MAX_RT_PRIO-1) + return -EINVAL; + if ((dl_policy(policy) && !__checkparam_dl(attr)) || + (rt_policy(policy) != (attr->sched_priority != 0))) + return -EINVAL; + + if (user) { + retval = user_check_sched_setscheduler(p, attr, policy, reset_on_fork); + if (retval) + return retval; + + if (attr->sched_flags & SCHED_FLAG_SUGOV) + return -EINVAL; + + retval = security_task_setscheduler(p); + if (retval) + return retval; + } + + /* Update task specific "requested" clamps */ + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) { + retval = uclamp_validate(p, attr); + if (retval) + return retval; + } + + /* + * SCHED_DEADLINE bandwidth accounting relies on stable cpusets + * information. + */ + if (dl_policy(policy) || dl_policy(p->policy)) { + cpuset_locked = true; + cpuset_lock(); + } + + /* + * Make sure no PI-waiters arrive (or leave) while we are + * changing the priority of the task: + * + * To be able to change p->policy safely, the appropriate + * runqueue lock must be held. + */ + rq = task_rq_lock(p, &rf); + update_rq_clock(rq); + + /* + * 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, + * but store a possible modification of reset_on_fork. + */ + if (unlikely(policy == p->policy)) { + if (fair_policy(policy) && attr->sched_nice != task_nice(p)) + goto change; + if (rt_policy(policy) && attr->sched_priority != p->rt_priority) + goto change; + if (dl_policy(policy) && dl_param_changed(p, attr)) + goto change; + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) + goto change; + + p->sched_reset_on_fork = reset_on_fork; + retval = 0; + goto unlock; + } +change: + + if (user) { +#ifdef CONFIG_RT_GROUP_SCHED + /* + * Do not allow real-time tasks into groups that have no runtime + * assigned. + */ + if (rt_bandwidth_enabled() && rt_policy(policy) && + task_group(p)->rt_bandwidth.rt_runtime == 0 && + !task_group_is_autogroup(task_group(p))) { + retval = -EPERM; + goto unlock; + } +#endif +#ifdef CONFIG_SMP + if (dl_bandwidth_enabled() && dl_policy(policy) && + !(attr->sched_flags & SCHED_FLAG_SUGOV)) { + cpumask_t *span = rq->rd->span; + + /* + * Don't allow tasks with an affinity mask smaller than + * the entire root_domain to become SCHED_DEADLINE. We + * will also fail if there's no bandwidth available. + */ + if (!cpumask_subset(span, p->cpus_ptr) || + rq->rd->dl_bw.bw == 0) { + retval = -EPERM; + goto unlock; + } + } +#endif + } + + /* Re-check policy now with rq lock held: */ + if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { + policy = oldpolicy = -1; + task_rq_unlock(rq, p, &rf); + if (cpuset_locked) + cpuset_unlock(); + goto recheck; + } + + /* + * If setscheduling to SCHED_DEADLINE (or changing the parameters + * of a SCHED_DEADLINE task) we need to check if enough bandwidth + * is available. + */ + if ((dl_policy(policy) || dl_task(p)) && sched_dl_overflow(p, policy, attr)) { + retval = -EBUSY; + goto unlock; + } + + p->sched_reset_on_fork = reset_on_fork; + oldprio = p->prio; + + newprio = __normal_prio(policy, attr->sched_priority, attr->sched_nice); + 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. + */ + newprio = rt_effective_prio(p, newprio); + if (newprio == oldprio) + queue_flags &= ~DEQUEUE_MOVE; + } + + queued = task_on_rq_queued(p); + running = task_current(rq, p); + if (queued) + dequeue_task(rq, p, queue_flags); + if (running) + put_prev_task(rq, p); + + prev_class = p->sched_class; + + if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) { + __setscheduler_params(p, attr); + __setscheduler_prio(p, newprio); + } + __setscheduler_uclamp(p, attr); + + if (queued) { + /* + * We enqueue to tail when the priority of a task is + * increased (user space view). + */ + if (oldprio < p->prio) + queue_flags |= ENQUEUE_HEAD; + + enqueue_task(rq, p, queue_flags); + } + if (running) + set_next_task(rq, p); + + check_class_changed(rq, p, prev_class, oldprio); + + /* Avoid rq from going away on us: */ + preempt_disable(); + head = splice_balance_callbacks(rq); + task_rq_unlock(rq, p, &rf); + + if (pi) { + if (cpuset_locked) + cpuset_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_rq_unlock(rq, p, &rf); + if (cpuset_locked) + cpuset_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); +} +EXPORT_SYMBOL_GPL(sched_setattr_nocheck); + +/** + * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernel-space. + * @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; + + if (!param || pid < 0) + return -EINVAL; + if (copy_from_user(&lparam, param, sizeof(struct sched_param))) + return -EFAULT; + + CLASS(find_get_task, p)(pid); + if (!p) + return -ESRCH; + + return sched_setscheduler(p, policy, &lparam); +} + +/* + * 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; + } + + if ((attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) && + size < SCHED_ATTR_SIZE_VER1) + return -EINVAL; + + /* + * 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, MIN_NICE, MAX_NICE); + + return 0; + +err_size: + put_user(sizeof(*attr), &uattr->size); + return -E2BIG; +} + +static void get_params(struct task_struct *p, struct sched_attr *attr) +{ + if (task_has_dl_policy(p)) + __getparam_dl(p, attr); + else if (task_has_rt_policy(p)) + attr->sched_priority = p->rt_priority; + else + attr->sched_nice = task_nice(p); +} + +/** + * sys_sched_setscheduler - set/change the scheduler policy and RT priority + * @pid: the pid in question. + * @policy: new policy. + * @param: structure containing the new RT priority. + * + * Return: 0 on success. An error code otherwise. + */ +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. + * @flags: for future extension. + */ +SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, + unsigned int, flags) +{ + struct sched_attr attr; + 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; + if (attr.sched_flags & SCHED_FLAG_KEEP_POLICY) + attr.sched_policy = SETPARAM_POLICY; + + CLASS(find_get_task, p)(pid); + if (!p) + return -ESRCH; + + if (attr.sched_flags & SCHED_FLAG_KEEP_PARAMS) + get_params(p, &attr); + + return sched_setattr(p, &attr); +} + +/** + * 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; + + if (pid < 0) + return -EINVAL; + + guard(rcu)(); + p = find_process_by_pid(pid); + if (!p) + return -ESRCH; + + retval = security_task_getscheduler(p); + if (!retval) { + retval = p->policy; + if (p->sched_reset_on_fork) + retval |= SCHED_RESET_ON_FORK; + } + return retval; +} + +/** + * sys_sched_getparam - 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; + + if (!param || pid < 0) + return -EINVAL; + + scoped_guard (rcu) { + p = find_process_by_pid(pid); + if (!p) + return -ESRCH; + + retval = security_task_getscheduler(p); + if (retval) + return retval; + + if (task_has_rt_policy(p)) + lp.sched_priority = p->rt_priority; + } + + /* + * This one might sleep, we cannot do it with a spinlock held ... + */ + return copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; +} + +/* + * 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; + + scoped_guard (rcu) { + p = find_process_by_pid(pid); + if (!p) + return -ESRCH; + + retval = security_task_getscheduler(p); + if (retval) + return retval; + + kattr.sched_policy = p->policy; + if (p->sched_reset_on_fork) + kattr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; + get_params(p, &kattr); + kattr.sched_flags &= SCHED_FLAG_ALL; + +#ifdef CONFIG_UCLAMP_TASK + /* + * This could race with another potential updater, but this is fine + * because it'll correctly read the old or the new value. We don't need + * to guarantee who wins the race as long as it doesn't return garbage. + */ + kattr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value; + kattr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value; +#endif + } + + return sched_attr_copy_to_user(uattr, &kattr, usize); +} + +#ifdef CONFIG_SMP +int dl_task_check_affinity(struct task_struct *p, const struct cpumask *mask) +{ + /* + * If the task isn't a deadline task or admission control is + * disabled then we don't care about affinity changes. + */ + if (!task_has_dl_policy(p) || !dl_bandwidth_enabled()) + return 0; + + /* + * Since bandwidth control happens on root_domain basis, + * if admission test is enabled, we only admit -deadline + * tasks allowed to run on all the CPUs in the task's + * root_domain. + */ + guard(rcu)(); + if (!cpumask_subset(task_rq(p)->rd->span, mask)) + return -EBUSY; + + return 0; +} +#endif /* CONFIG_SMP */ + +int __sched_setaffinity(struct task_struct *p, struct affinity_context *ctx) +{ + int retval; + cpumask_var_t cpus_allowed, new_mask; + + if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) + return -ENOMEM; + + if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_free_cpus_allowed; + } + + cpuset_cpus_allowed(p, cpus_allowed); + cpumask_and(new_mask, ctx->new_mask, cpus_allowed); + + ctx->new_mask = new_mask; + ctx->flags |= SCA_CHECK; + + retval = dl_task_check_affinity(p, new_mask); + if (retval) + goto out_free_new_mask; + + retval = __set_cpus_allowed_ptr(p, ctx); + if (retval) + goto out_free_new_mask; + + 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 cpumask to the cpuset's cpus_allowed. + */ + cpumask_copy(new_mask, cpus_allowed); + + /* + * If SCA_USER is set, a 2nd call to __set_cpus_allowed_ptr() + * will restore the previous user_cpus_ptr value. + * + * In the unlikely event a previous user_cpus_ptr exists, + * we need to further restrict the mask to what is allowed + * by that old user_cpus_ptr. + */ + if (unlikely((ctx->flags & SCA_USER) && ctx->user_mask)) { + bool empty = !cpumask_and(new_mask, new_mask, + ctx->user_mask); + + if (WARN_ON_ONCE(empty)) + cpumask_copy(new_mask, cpus_allowed); + } + __set_cpus_allowed_ptr(p, ctx); + retval = -EINVAL; + } + +out_free_new_mask: + free_cpumask_var(new_mask); +out_free_cpus_allowed: + free_cpumask_var(cpus_allowed); + return retval; +} + +long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) +{ + struct affinity_context ac; + struct cpumask *user_mask; + int retval; + + CLASS(find_get_task, p)(pid); + if (!p) + return -ESRCH; + + if (p->flags & PF_NO_SETAFFINITY) + return -EINVAL; + + if (!check_same_owner(p)) { + guard(rcu)(); + if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) + return -EPERM; + } + + retval = security_task_setscheduler(p); + if (retval) + return retval; + + /* + * With non-SMP configs, user_cpus_ptr/user_mask isn't used and + * alloc_user_cpus_ptr() returns NULL. + */ + user_mask = alloc_user_cpus_ptr(NUMA_NO_NODE); + if (user_mask) { + cpumask_copy(user_mask, in_mask); + } else if (IS_ENABLED(CONFIG_SMP)) { + return -ENOMEM; + } + + ac = (struct affinity_context){ + .new_mask = in_mask, + .user_mask = user_mask, + .flags = SCA_USER, + }; + + retval = __sched_setaffinity(p, &ac); + kfree(ac.user_mask); + + 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, struct cpumask *mask) +{ + struct task_struct *p; + int retval; + + guard(rcu)(); + p = find_process_by_pid(pid); + if (!p) + return -ESRCH; + + retval = security_task_getscheduler(p); + if (retval) + return retval; + + guard(raw_spinlock_irqsave)(&p->pi_lock); + cpumask_and(mask, &p->cpus_mask, cpu_active_mask); + + return 0; +} + +/** + * 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 (!zalloc_cpumask_var(&mask, GFP_KERNEL)) + return -ENOMEM; + + ret = sched_getaffinity(pid, mask); + if (ret == 0) { + unsigned int retlen = min(len, cpumask_size()); + + if (copy_to_user(user_mask_ptr, cpumask_bits(mask), retlen)) + ret = -EFAULT; + else + ret = retlen; + } + free_cpumask_var(mask); + + return ret; +} + +static void do_sched_yield(void) +{ + struct rq_flags rf; + struct rq *rq; + + rq = this_rq_lock_irq(&rf); + + schedstat_inc(rq->yld_count); + current->sched_class->yield_task(rq); + + preempt_disable(); + rq_unlock_irq(rq, &rf); + 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; +} + +/** + * 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. + * + * 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) +{ + struct task_struct *curr = current; + struct rq *rq, *p_rq; + int yielded = 0; + + scoped_guard (irqsave) { + rq = this_rq(); + +again: + p_rq = task_rq(p); + /* + * If we're the only runnable task on the rq and target rq also + * has only one task, there's absolutely no point in yielding. + */ + if (rq->nr_running == 1 && p_rq->nr_running == 1) + return -ESRCH; + + guard(double_rq_lock)(rq, p_rq); + if (task_rq(p) != p_rq) + goto again; + + if (!curr->sched_class->yield_to_task) + return 0; + + if (curr->sched_class != p->sched_class) + return 0; + + if (task_on_cpu(p_rq, p) || !task_is_running(p)) + return 0; + + yielded = curr->sched_class->yield_to_task(rq, p); + if (yielded) { + schedstat_inc(rq->yld_count); + /* + * Make p's CPU reschedule; pick_next_entity + * takes care of fairness. + */ + if (preempt && rq != p_rq) + resched_curr(p_rq); + } + } + + if (yielded) + schedule(); + + return yielded; +} +EXPORT_SYMBOL_GPL(yield_to); + +/** + * 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_DEADLINE: + 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_DEADLINE: + case SCHED_NORMAL: + case SCHED_BATCH: + case SCHED_IDLE: + ret = 0; + } + return ret; +} + +static int sched_rr_get_interval(pid_t pid, struct timespec64 *t) +{ + unsigned int time_slice = 0; + int retval; + + if (pid < 0) + return -EINVAL; + + scoped_guard (rcu) { + struct task_struct *p = find_process_by_pid(pid); + if (!p) + return -ESRCH; + + retval = security_task_getscheduler(p); + if (retval) + return retval; + + scoped_guard (task_rq_lock, p) { + struct rq *rq = scope.rq; + if (p->sched_class->get_rr_interval) + time_slice = p->sched_class->get_rr_interval(rq, p); + } + } + + jiffies_to_timespec64(time_slice, t); + return 0; +} + +/** + * sys_sched_rr_get_interval - return the default time-slice of a process. + * @pid: pid of the process. + * @interval: userspace pointer to the time-slice value. + * + * this syscall writes the default time-slice value of a given process + * into the user-space timespec buffer. A value of '0' means infinity. + * + * Return: On success, 0 and the time-slice 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 diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index a6994a1fcc90..784a0be81e84 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -501,7 +501,7 @@ void rq_attach_root(struct rq *rq, struct root_domain *rd) cpumask_clear_cpu(rq->cpu, old_rd->span); /* - * If we dont want to free the old_rd yet then + * If we don't want to free the old_rd yet then * set old_rd to NULL to skip the freeing later * in this function: */ @@ -1176,7 +1176,7 @@ fail: * uniquely identify each group (for a given domain): * * - The first is the balance_cpu (see should_we_balance() and the - * load-balance blub in fair.c); for each group we only want 1 CPU to + * load-balance blurb in fair.c); for each group we only want 1 CPU to * continue balancing at a higher domain. * * - The second is the sched_group_capacity; we want all identical groups @@ -1388,7 +1388,7 @@ static inline void asym_cpu_capacity_update_data(int cpu) /* * Search if capacity already exits. If not, track which the entry - * where we should insert to keep the list ordered descendingly. + * where we should insert to keep the list ordered descending. */ list_for_each_entry(entry, &asym_cap_list, link) { if (capacity == entry->capacity) @@ -1853,7 +1853,7 @@ void sched_init_numa(int offline_node) struct cpumask ***masks; /* - * O(nr_nodes^2) deduplicating selection sort -- in order to find the + * O(nr_nodes^2) de-duplicating selection sort -- in order to find the * unique distances in the node_distance() table. */ distance_map = bitmap_alloc(NR_DISTANCE_VALUES, GFP_KERNEL); @@ -2750,7 +2750,7 @@ match2: } #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) - /* Build perf. domains: */ + /* Build perf domains: */ for (i = 0; i < ndoms_new; i++) { for (j = 0; j < n && !sched_energy_update; j++) { if (cpumask_equal(doms_new[i], doms_cur[j]) && @@ -2759,7 +2759,7 @@ match2: goto match3; } } - /* No match - add perf. domains for a new rd */ + /* No match - add perf domains for a new rd */ has_eas |= build_perf_domains(doms_new[i]); match3: ; diff --git a/kernel/sched/wait_bit.c b/kernel/sched/wait_bit.c index 0b1cd985dc27..134d7112ef71 100644 --- a/kernel/sched/wait_bit.c +++ b/kernel/sched/wait_bit.c @@ -33,7 +33,7 @@ int wake_bit_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync EXPORT_SYMBOL(wake_bit_function); /* - * To allow interruptible waiting and asynchronous (i.e. nonblocking) + * To allow interruptible waiting and asynchronous (i.e. non-blocking) * waiting, the actions of __wait_on_bit() and __wait_on_bit_lock() are * permitted return codes. Nonzero return codes halt waiting and return. */ @@ -133,7 +133,7 @@ EXPORT_SYMBOL(__wake_up_bit); * @bit: the bit of the word being waited on * * There is a standard hashed waitqueue table for generic use. This - * is the part of the hashtable's accessor API that wakes up waiters + * is the part of the hash-table's accessor API that wakes up waiters * on a bit. For instance, if one were to have waiters on a bitflag, * one would call wake_up_bit() after clearing the bit. * |