diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 16:39:53 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-08 16:39:53 -0700 |
commit | dad1c12ed831a7a89cc01e5582cd0b81a4be7f19 (patch) | |
tree | 7a84799d3108bd9d3f1d4b530afd3ff9300db982 /kernel/sched | |
parent | 090bc5a2a91499c1fd64b78d125daa6ca5531d38 (diff) | |
parent | af24bde8df2029f067dc46aff0393c8f18ff6e2f (diff) |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Remove the unused per rq load array and all its infrastructure, by
Dietmar Eggemann.
- Add utilization clamping support by Patrick Bellasi. This is a
refinement of the energy aware scheduling framework with support for
boosting of interactive and capping of background workloads: to make
sure critical GUI threads get maximum frequency ASAP, and to make
sure background processing doesn't unnecessarily move to cpufreq
governor to higher frequencies and less energy efficient CPU modes.
- Add the bare minimum of tracepoints required for LISA EAS regression
testing, by Qais Yousef - which allows automated testing of various
power management features, including energy aware scheduling.
- Restructure the former tsk_nr_cpus_allowed() facility that the -rt
kernel used to modify the scheduler's CPU affinity logic such as
migrate_disable() - introduce the task->cpus_ptr value instead of
taking the address of &task->cpus_allowed directly - by Sebastian
Andrzej Siewior.
- Misc optimizations, fixes, cleanups and small enhancements - see the
Git log for details.
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
sched/uclamp: Add uclamp support to energy_compute()
sched/uclamp: Add uclamp_util_with()
sched/cpufreq, sched/uclamp: Add clamps for FAIR and RT tasks
sched/uclamp: Set default clamps for RT tasks
sched/uclamp: Reset uclamp values on RESET_ON_FORK
sched/uclamp: Extend sched_setattr() to support utilization clamping
sched/core: Allow sched_setattr() to use the current policy
sched/uclamp: Add system default clamps
sched/uclamp: Enforce last task's UCLAMP_MAX
sched/uclamp: Add bucket local max tracking
sched/uclamp: Add CPU's clamp buckets refcounting
sched/fair: Rename weighted_cpuload() to cpu_runnable_load()
sched/debug: Export the newly added tracepoints
sched/debug: Add sched_overutilized tracepoint
sched/debug: Add new tracepoint to track PELT at se level
sched/debug: Add new tracepoints to track PELT at rq level
sched/debug: Add a new sched_trace_*() helper functions
sched/autogroup: Make autogroup_path() always available
sched/wait: Deduplicate code with do-while
sched/topology: Remove unused 'sd' parameter from arch_scale_cpu_capacity()
...
Diffstat (limited to 'kernel/sched')
-rw-r--r-- | kernel/sched/autogroup.c | 2 | ||||
-rw-r--r-- | kernel/sched/core.c | 533 | ||||
-rw-r--r-- | kernel/sched/cpudeadline.c | 4 | ||||
-rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 24 | ||||
-rw-r--r-- | kernel/sched/cpupri.c | 4 | ||||
-rw-r--r-- | kernel/sched/deadline.c | 8 | ||||
-rw-r--r-- | kernel/sched/debug.c | 43 | ||||
-rw-r--r-- | kernel/sched/fair.c | 623 | ||||
-rw-r--r-- | kernel/sched/features.h | 1 | ||||
-rw-r--r-- | kernel/sched/pelt.c | 13 | ||||
-rw-r--r-- | kernel/sched/pelt.h | 2 | ||||
-rw-r--r-- | kernel/sched/rt.c | 8 | ||||
-rw-r--r-- | kernel/sched/sched-pelt.h | 2 | ||||
-rw-r--r-- | kernel/sched/sched.h | 134 | ||||
-rw-r--r-- | kernel/sched/topology.c | 18 | ||||
-rw-r--r-- | kernel/sched/wait.c | 8 |
16 files changed, 887 insertions, 540 deletions
diff --git a/kernel/sched/autogroup.c b/kernel/sched/autogroup.c index 2d4ff5353ded..2067080bb235 100644 --- a/kernel/sched/autogroup.c +++ b/kernel/sched/autogroup.c @@ -259,7 +259,6 @@ out: } #endif /* CONFIG_PROC_FS */ -#ifdef CONFIG_SCHED_DEBUG int autogroup_path(struct task_group *tg, char *buf, int buflen) { if (!task_group_is_autogroup(tg)) @@ -267,4 +266,3 @@ int autogroup_path(struct task_group *tg, char *buf, int buflen) return snprintf(buf, buflen, "%s-%ld", "/autogroup", tg->autogroup->id); } -#endif diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 874c427742a9..fa43ce3962e7 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -23,6 +23,17 @@ #define CREATE_TRACE_POINTS #include <trace/events/sched.h> +/* + * Export tracepoints that act as a bare tracehook (ie: have no trace event + * associated with them) to allow external modules to probe them. + */ +EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_cfs_tp); +EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_rt_tp); +EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_dl_tp); +EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_irq_tp); +EXPORT_TRACEPOINT_SYMBOL_GPL(pelt_se_tp); +EXPORT_TRACEPOINT_SYMBOL_GPL(sched_overutilized_tp); + DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL) @@ -761,6 +772,401 @@ static void set_load_weight(struct task_struct *p, bool update_load) } } +#ifdef CONFIG_UCLAMP_TASK +/* Max allowed minimum utilization */ +unsigned int sysctl_sched_uclamp_util_min = SCHED_CAPACITY_SCALE; + +/* Max allowed maximum utilization */ +unsigned int sysctl_sched_uclamp_util_max = SCHED_CAPACITY_SCALE; + +/* All clamps are required to be less or equal than these values */ +static struct uclamp_se uclamp_default[UCLAMP_CNT]; + +/* 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 clamp_value / UCLAMP_BUCKET_DELTA; +} + +static inline unsigned int uclamp_bucket_base_value(unsigned int clamp_value) +{ + return UCLAMP_BUCKET_DELTA * uclamp_bucket_id(clamp_value); +} + +static inline unsigned int uclamp_none(int 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, unsigned int clamp_id, + unsigned int clamp_value) +{ + /* + * Avoid blocked utilization pushing up the frequency when we go + * idle (which drops the max-clamp) by retaining the last known + * max-clamp. + */ + if (clamp_id == UCLAMP_MAX) { + rq->uclamp_flags |= UCLAMP_FLAG_IDLE; + return clamp_value; + } + + return uclamp_none(UCLAMP_MIN); +} + +static inline void uclamp_idle_reset(struct rq *rq, unsigned int clamp_id, + unsigned int clamp_value) +{ + /* Reset max-clamp retention only on idle exit */ + if (!(rq->uclamp_flags & UCLAMP_FLAG_IDLE)) + return; + + WRITE_ONCE(rq->uclamp[clamp_id].value, clamp_value); +} + +static inline +unsigned int uclamp_rq_max_value(struct rq *rq, unsigned int clamp_id, + unsigned int clamp_value) +{ + struct uclamp_bucket *bucket = rq->uclamp[clamp_id].bucket; + int bucket_id = UCLAMP_BUCKETS - 1; + + /* + * Since both min and max clamps are max aggregated, find the + * top most bucket with tasks in. + */ + for ( ; bucket_id >= 0; bucket_id--) { + if (!bucket[bucket_id].tasks) + continue; + return bucket[bucket_id].value; + } + + /* No tasks -- default clamp values */ + return uclamp_idle_value(rq, clamp_id, clamp_value); +} + +/* + * The effective clamp bucket index of a task depends on, by increasing + * priority: + * - the task specific clamp value, when explicitly requested from userspace + * - the system default clamp value, defined by the sysadmin + */ +static inline struct uclamp_se +uclamp_eff_get(struct task_struct *p, unsigned int clamp_id) +{ + struct uclamp_se uc_req = p->uclamp_req[clamp_id]; + struct uclamp_se uc_max = uclamp_default[clamp_id]; + + /* System default restrictions always apply */ + if (unlikely(uc_req.value > uc_max.value)) + return uc_max; + + return uc_req; +} + +unsigned int uclamp_eff_value(struct task_struct *p, unsigned int clamp_id) +{ + struct uclamp_se uc_eff; + + /* Task currently refcounted: use back-annotated (effective) value */ + if (p->uclamp[clamp_id].active) + return p->uclamp[clamp_id].value; + + uc_eff = uclamp_eff_get(p, clamp_id); + + return uc_eff.value; +} + +/* + * When a task is enqueued on a rq, the clamp bucket currently defined by the + * task's uclamp::bucket_id is refcounted on that rq. This also immediately + * updates the rq's clamp value if required. + * + * Tasks can have a task-specific value requested from user-space, track + * within each bucket the maximum value for tasks refcounted in it. + * This "local max aggregation" allows to track the exact "requested" value + * for each bucket when all its RUNNABLE tasks require the same clamp. + */ +static inline void uclamp_rq_inc_id(struct rq *rq, struct task_struct *p, + unsigned int clamp_id) +{ + struct uclamp_rq *uc_rq = &rq->uclamp[clamp_id]; + struct uclamp_se *uc_se = &p->uclamp[clamp_id]; + struct uclamp_bucket *bucket; + + lockdep_assert_held(&rq->lock); + + /* Update task effective clamp */ + p->uclamp[clamp_id] = uclamp_eff_get(p, clamp_id); + + bucket = &uc_rq->bucket[uc_se->bucket_id]; + bucket->tasks++; + uc_se->active = true; + + uclamp_idle_reset(rq, clamp_id, uc_se->value); + + /* + * Local max aggregation: rq buckets always track the max + * "requested" clamp value of its RUNNABLE tasks. + */ + if (bucket->tasks == 1 || uc_se->value > bucket->value) + bucket->value = uc_se->value; + + if (uc_se->value > READ_ONCE(uc_rq->value)) + WRITE_ONCE(uc_rq->value, uc_se->value); +} + +/* + * When a task is dequeued from a rq, the clamp bucket refcounted by the task + * is released. If this is the last task reference counting the rq's max + * active clamp value, then the rq's clamp value is updated. + * + * Both refcounted tasks and rq's cached clamp values are expected to be + * always valid. If it's detected they are not, as defensive programming, + * enforce the expected state and warn. + */ +static inline void uclamp_rq_dec_id(struct rq *rq, struct task_struct *p, + unsigned int clamp_id) +{ + struct uclamp_rq *uc_rq = &rq->uclamp[clamp_id]; + struct uclamp_se *uc_se = &p->uclamp[clamp_id]; + struct uclamp_bucket *bucket; + unsigned int bkt_clamp; + unsigned int rq_clamp; + + lockdep_assert_held(&rq->lock); + + bucket = &uc_rq->bucket[uc_se->bucket_id]; + SCHED_WARN_ON(!bucket->tasks); + if (likely(bucket->tasks)) + bucket->tasks--; + uc_se->active = false; + + /* + * Keep "local max aggregation" simple and accept to (possibly) + * overboost some RUNNABLE tasks in the same bucket. + * The rq clamp bucket value is reset to its base value whenever + * there are no more RUNNABLE tasks refcounting it. + */ + if (likely(bucket->tasks)) + return; + + rq_clamp = READ_ONCE(uc_rq->value); + /* + * Defensive programming: this should never happen. If it happens, + * e.g. due to future modification, warn and fixup the expected value. + */ + SCHED_WARN_ON(bucket->value > rq_clamp); + if (bucket->value >= rq_clamp) { + bkt_clamp = uclamp_rq_max_value(rq, clamp_id, uc_se->value); + WRITE_ONCE(uc_rq->value, bkt_clamp); + } +} + +static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p) +{ + unsigned int clamp_id; + + if (unlikely(!p->sched_class->uclamp_enabled)) + return; + + for_each_clamp_id(clamp_id) + uclamp_rq_inc_id(rq, p, clamp_id); + + /* Reset clamp idle holding when there is one RUNNABLE task */ + if (rq->uclamp_flags & UCLAMP_FLAG_IDLE) + rq->uclamp_flags &= ~UCLAMP_FLAG_IDLE; +} + +static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p) +{ + unsigned int clamp_id; + + if (unlikely(!p->sched_class->uclamp_enabled)) + return; + + for_each_clamp_id(clamp_id) + uclamp_rq_dec_id(rq, p, clamp_id); +} + +int sysctl_sched_uclamp_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos) +{ + int old_min, old_max; + static DEFINE_MUTEX(mutex); + int result; + + mutex_lock(&mutex); + old_min = sysctl_sched_uclamp_util_min; + old_max = sysctl_sched_uclamp_util_max; + + result = proc_dointvec(table, write, buffer, lenp, ppos); + if (result) + goto undo; + if (!write) + goto done; + + if (sysctl_sched_uclamp_util_min > sysctl_sched_uclamp_util_max || + sysctl_sched_uclamp_util_max > SCHED_CAPACITY_SCALE) { + result = -EINVAL; + goto undo; + } + + if (old_min != sysctl_sched_uclamp_util_min) { + uclamp_se_set(&uclamp_default[UCLAMP_MIN], + sysctl_sched_uclamp_util_min, false); + } + if (old_max != sysctl_sched_uclamp_util_max) { + uclamp_se_set(&uclamp_default[UCLAMP_MAX], + sysctl_sched_uclamp_util_max, false); + } + + /* + * Updating all the RUNNABLE task is expensive, keep it simple and do + * just a lazy update at each next enqueue time. + */ + goto done; + +undo: + sysctl_sched_uclamp_util_min = old_min; + sysctl_sched_uclamp_util_max = old_max; +done: + mutex_unlock(&mutex); + + return result; +} + +static int uclamp_validate(struct task_struct *p, + const struct sched_attr *attr) +{ + unsigned int lower_bound = p->uclamp_req[UCLAMP_MIN].value; + unsigned int upper_bound = p->uclamp_req[UCLAMP_MAX].value; + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) + lower_bound = attr->sched_util_min; + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) + upper_bound = attr->sched_util_max; + + if (lower_bound > upper_bound) + return -EINVAL; + if (upper_bound > SCHED_CAPACITY_SCALE) + return -EINVAL; + + return 0; +} + +static void __setscheduler_uclamp(struct task_struct *p, + const struct sched_attr *attr) +{ + unsigned int clamp_id; + + /* + * On scheduling class change, reset to default clamps for tasks + * without a task-specific value. + */ + for_each_clamp_id(clamp_id) { + struct uclamp_se *uc_se = &p->uclamp_req[clamp_id]; + unsigned int clamp_value = uclamp_none(clamp_id); + + /* Keep using defined clamps across class changes */ + if (uc_se->user_defined) + continue; + + /* By default, RT tasks always get 100% boost */ + if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN)) + clamp_value = uclamp_none(UCLAMP_MAX); + + uclamp_se_set(uc_se, clamp_value, false); + } + + if (likely(!(attr->sched_flags & SCHED_FLAG_UTIL_CLAMP))) + return; + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MIN) { + uclamp_se_set(&p->uclamp_req[UCLAMP_MIN], + attr->sched_util_min, true); + } + + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP_MAX) { + uclamp_se_set(&p->uclamp_req[UCLAMP_MAX], + attr->sched_util_max, true); + } +} + +static void uclamp_fork(struct task_struct *p) +{ + unsigned int clamp_id; + + for_each_clamp_id(clamp_id) + p->uclamp[clamp_id].active = false; + + if (likely(!p->sched_reset_on_fork)) + return; + + for_each_clamp_id(clamp_id) { + unsigned int clamp_value = uclamp_none(clamp_id); + + /* By default, RT tasks always get 100% boost */ + if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN)) + clamp_value = uclamp_none(UCLAMP_MAX); + + uclamp_se_set(&p->uclamp_req[clamp_id], clamp_value, false); + } +} + +static void __init init_uclamp(void) +{ + struct uclamp_se uc_max = {}; + unsigned int clamp_id; + int cpu; + + for_each_possible_cpu(cpu) { + memset(&cpu_rq(cpu)->uclamp, 0, sizeof(struct uclamp_rq)); + cpu_rq(cpu)->uclamp_flags = 0; + } + + for_each_clamp_id(clamp_id) { + uclamp_se_set(&init_task.uclamp_req[clamp_id], + uclamp_none(clamp_id), false); + } + + /* System defaults allow max clamp values for both indexes */ + uclamp_se_set(&uc_max, uclamp_none(UCLAMP_MAX), false); + for_each_clamp_id(clamp_id) + uclamp_default[clamp_id] = uc_max; +} + +#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 init_uclamp(void) { } +#endif /* CONFIG_UCLAMP_TASK */ + static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) { if (!(flags & ENQUEUE_NOCLOCK)) @@ -771,6 +1177,7 @@ static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags) psi_enqueue(p, flags & ENQUEUE_WAKEUP); } + uclamp_rq_inc(rq, p); p->sched_class->enqueue_task(rq, p, flags); } @@ -784,6 +1191,7 @@ static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags) psi_dequeue(p, flags & DEQUEUE_SLEEP); } + uclamp_rq_dec(rq, p); p->sched_class->dequeue_task(rq, p, flags); } @@ -930,7 +1338,7 @@ static inline bool is_per_cpu_kthread(struct task_struct *p) */ static inline bool is_cpu_allowed(struct task_struct *p, int cpu) { - if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) + if (!cpumask_test_cpu(cpu, p->cpus_ptr)) return false; if (is_per_cpu_kthread(p)) @@ -1025,7 +1433,7 @@ static int migration_cpu_stop(void *data) local_irq_disable(); /* * We need to explicitly wake pending tasks before running - * __migrate_task() such that we will not miss enforcing cpus_allowed + * __migrate_task() such that we will not miss enforcing cpus_ptr * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test. */ sched_ttwu_pending(); @@ -1056,7 +1464,7 @@ static int migration_cpu_stop(void *data) */ void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask) { - cpumask_copy(&p->cpus_allowed, new_mask); + cpumask_copy(&p->cpus_mask, new_mask); p->nr_cpus_allowed = cpumask_weight(new_mask); } @@ -1126,7 +1534,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p, goto out; } - if (cpumask_equal(&p->cpus_allowed, new_mask)) + if (cpumask_equal(p->cpus_ptr, new_mask)) goto out; if (!cpumask_intersects(new_mask, cpu_valid_mask)) { @@ -1286,10 +1694,10 @@ static int migrate_swap_stop(void *data) if (task_cpu(arg->src_task) != arg->src_cpu) goto unlock; - if (!cpumask_test_cpu(arg->dst_cpu, &arg->src_task->cpus_allowed)) + if (!cpumask_test_cpu(arg->dst_cpu, arg->src_task->cpus_ptr)) goto unlock; - if (!cpumask_test_cpu(arg->src_cpu, &arg->dst_task->cpus_allowed)) + if (!cpumask_test_cpu(arg->src_cpu, arg->dst_task->cpus_ptr)) goto unlock; __migrate_swap_task(arg->src_task, arg->dst_cpu); @@ -1331,10 +1739,10 @@ int migrate_swap(struct task_struct *cur, struct task_struct *p, if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu)) goto out; - if (!cpumask_test_cpu(arg.dst_cpu, &arg.src_task->cpus_allowed)) + if (!cpumask_test_cpu(arg.dst_cpu, arg.src_task->cpus_ptr)) goto out; - if (!cpumask_test_cpu(arg.src_cpu, &arg.dst_task->cpus_allowed)) + if (!cpumask_test_cpu(arg.src_cpu, arg.dst_task->cpus_ptr)) goto out; trace_sched_swap_numa(cur, arg.src_cpu, p, arg.dst_cpu); @@ -1479,7 +1887,7 @@ void kick_process(struct task_struct *p) EXPORT_SYMBOL_GPL(kick_process); /* - * ->cpus_allowed is protected by both rq->lock and p->pi_lock + * ->cpus_ptr is protected by both rq->lock and p->pi_lock * * A few notes on cpu_active vs cpu_online: * @@ -1519,14 +1927,14 @@ static int select_fallback_rq(int cpu, struct task_struct *p) for_each_cpu(dest_cpu, nodemask) { if (!cpu_active(dest_cpu)) continue; - if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) + if (cpumask_test_cpu(dest_cpu, p->cpus_ptr)) return dest_cpu; } } for (;;) { /* Any allowed, online CPU? */ - for_each_cpu(dest_cpu, &p->cpus_allowed) { + for_each_cpu(dest_cpu, p->cpus_ptr) { if (!is_cpu_allowed(p, dest_cpu)) continue; @@ -1570,7 +1978,7 @@ out: } /* - * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. + * The caller (fork, wakeup) owns p->pi_lock, ->cpus_ptr is stable. */ static inline int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) @@ -1580,11 +1988,11 @@ int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) if (p->nr_cpus_allowed > 1) cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags); else - cpu = cpumask_any(&p->cpus_allowed); + cpu = cpumask_any(p->cpus_ptr); /* * In order not to call set_task_cpu() on a blocking task we need - * to rely on ttwu() to place the task on a valid ->cpus_allowed + * to rely on ttwu() to place the task on a valid ->cpus_ptr * CPU. * * Since this is common to all placement strategies, this lives here. @@ -1991,6 +2399,29 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) unsigned long flags; int cpu, success = 0; + if (p == current) { + /* + * We're waking current, this means 'p->on_rq' and 'task_cpu(p) + * == smp_processor_id()'. Together this means we can special + * case the whole 'p->on_rq && ttwu_remote()' case below + * without taking any locks. + * + * In particular: + * - we rely on Program-Order guarantees for all the ordering, + * - we're serialized against set_special_state() by virtue of + * it disabling IRQs (this allows not taking ->pi_lock). + */ + if (!(p->state & state)) + return false; + + success = 1; + cpu = task_cpu(p); + trace_sched_waking(p); + p->state = TASK_RUNNING; + trace_sched_wakeup(p); + goto out; + } + /* * If we are going to wake up a thread waiting for CONDITION we * need to ensure that CONDITION=1 done by the caller can not be @@ -2000,7 +2431,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) raw_spin_lock_irqsave(&p->pi_lock, flags); smp_mb__after_spinlock(); if (!(p->state & state)) - goto out; + goto unlock; trace_sched_waking(p); @@ -2030,7 +2461,7 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) */ smp_rmb(); if (p->on_rq && ttwu_remote(p, wake_flags)) - goto stat; + goto unlock; #ifdef CONFIG_SMP /* @@ -2090,10 +2521,11 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) #endif /* CONFIG_SMP */ ttwu_queue(p, cpu, wake_flags); -stat: - ttwu_stat(p, cpu, wake_flags); -out: +unlock: raw_spin_unlock_irqrestore(&p->pi_lock, flags); +out: + if (success) + ttwu_stat(p, cpu, wake_flags); return success; } @@ -2300,6 +2732,8 @@ int sched_fork(unsigned long clone_flags, struct task_struct *p) */ p->prio = current->normal_prio; + uclamp_fork(p); + /* * Revert to default priority/policy on fork if requested. */ @@ -2395,7 +2829,7 @@ void wake_up_new_task(struct task_struct *p) #ifdef CONFIG_SMP /* * Fork balancing, do it here and not earlier because: - * - cpus_allowed can change in the fork path + * - cpus_ptr can change in the fork path * - any previously selected CPU might disappear through hotplug * * Use __set_task_cpu() to avoid calling sched_class::migrate_task_rq, @@ -3033,7 +3467,6 @@ void scheduler_tick(void) update_rq_clock(rq); curr->sched_class->task_tick(rq, curr, 0); - cpu_load_update_active(rq); calc_global_load_tick(rq); psi_task_tick(rq); @@ -4071,6 +4504,13 @@ static void __setscheduler_params(struct task_struct *p, static void __setscheduler(struct rq *rq, struct task_struct *p, const struct sched_attr *attr, bool keep_boost) { + /* + * If params can't change scheduling class changes aren't allowed + * either. + */ + if (attr->sched_flags & SCHED_FLAG_KEEP_PARAMS) + return; + __setscheduler_params(p, attr); /* @@ -4208,6 +4648,13 @@ recheck: return retval; } + /* Update task specific "requested" clamps */ + if (attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) { + retval = uclamp_validate(p, attr); + if (retval) + return retval; + } + /* * Make sure no PI-waiters arrive (or leave) while we are * changing the priority of the task: @@ -4237,6 +4684,8 @@ recheck: 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; task_rq_unlock(rq, p, &rf); @@ -4267,7 +4716,7 @@ change: * the entire root_domain to become SCHED_DEADLINE. We * will also fail if there's no bandwidth available. */ - if (!cpumask_subset(span, &p->cpus_allowed) || + if (!cpumask_subset(span, p->cpus_ptr) || rq->rd->dl_bw.bw == 0) { task_rq_unlock(rq, p, &rf); return -EPERM; @@ -4317,7 +4766,9 @@ change: put_prev_task(rq, p); prev_class = p->sched_class; + __setscheduler(rq, p, attr, pi); + __setscheduler_uclamp(p, attr); if (queued) { /* @@ -4493,6 +4944,10 @@ static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *a if (ret) return -EFAULT; + 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? @@ -4556,14 +5011,21 @@ SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, if ((int)attr.sched_policy < 0) return -EINVAL; + if (attr.sched_flags & SCHED_FLAG_KEEP_POLICY) + attr.sched_policy = SETPARAM_POLICY; rcu_read_lock(); retval = -ESRCH; p = find_process_by_pid(pid); - if (p != NULL) - retval = sched_setattr(p, &attr); + if (likely(p)) + get_task_struct(p); rcu_read_unlock(); + if (likely(p)) { + retval = sched_setattr(p, &attr); + put_task_struct(p); + } + return retval; } @@ -4714,6 +5176,11 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, else attr.sched_nice = task_nice(p); +#ifdef CONFIG_UCLAMP_TASK + attr.sched_util_min = p->uclamp_req[UCLAMP_MIN].value; + attr.sched_util_max = p->uclamp_req[UCLAMP_MAX].value; +#endif + rcu_read_unlock(); retval = sched_read_attr(uattr, &attr, size); @@ -4866,7 +5333,7 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask) goto out_unlock; raw_spin_lock_irqsave(&p->pi_lock, flags); - cpumask_and(mask, &p->cpus_allowed, cpu_active_mask); + cpumask_and(mask, &p->cpus_mask, cpu_active_mask); raw_spin_unlock_irqrestore(&p->pi_lock, flags); out_unlock: @@ -5123,7 +5590,7 @@ long __sched io_schedule_timeout(long timeout) } EXPORT_SYMBOL(io_schedule_timeout); -void io_schedule(void) +void __sched io_schedule(void) { int token; @@ -5443,7 +5910,7 @@ int task_can_attach(struct task_struct *p, * allowed nodes is unnecessary. Thus, cpusets are not * applicable for such threads. This prevents checking for * success of set_cpus_allowed_ptr() on all attached tasks - * before cpus_allowed may be changed. + * before cpus_mask may be changed. */ if (p->flags & PF_NO_SETAFFINITY) { ret = -EINVAL; @@ -5470,7 +5937,7 @@ int migrate_task_to(struct task_struct *p, int target_cpu) if (curr_cpu == target_cpu) return 0; - if (!cpumask_test_cpu(target_cpu, &p->cpus_allowed)) + if (!cpumask_test_cpu(target_cpu, p->cpus_ptr)) return -EINVAL; /* TODO: This is not properly updating schedstats */ @@ -5608,7 +6075,7 @@ static void migrate_tasks(struct rq *dead_rq, struct rq_flags *rf) put_prev_task(rq, next); /* - * Rules for changing task_struct::cpus_allowed are holding + * Rules for changing task_struct::cpus_mask are holding * both pi_lock and rq->lock, such that holding either * stabilizes the mask. * @@ -5902,8 +6369,8 @@ DECLARE_PER_CPU(cpumask_var_t, select_idle_mask); void __init sched_init(void) { - int i, j; unsigned long alloc_size = 0, ptr; + int i; wait_bit_init(); @@ -6005,10 +6472,6 @@ void __init sched_init(void) #ifdef CONFIG_RT_GROUP_SCHED init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); #endif - - for (j = 0; j < CPU_LOAD_IDX_MAX; j++) - rq->cpu_load[j] = 0; - #ifdef CONFIG_SMP rq->sd = NULL; rq->rd = NULL; @@ -6063,6 +6526,8 @@ void __init sched_init(void) psi_init(); + init_uclamp(); + scheduler_running = 1; } diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index ec4e4a9aab5f..5cc4012572ec 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -120,14 +120,14 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, const struct sched_dl_entity *dl_se = &p->dl; if (later_mask && - cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) { + cpumask_and(later_mask, cp->free_cpus, p->cpus_ptr)) { return 1; } else { int best_cpu = cpudl_maximum(cp); WARN_ON(best_cpu != -1 && !cpu_present(best_cpu)); - if (cpumask_test_cpu(best_cpu, &p->cpus_allowed) && + if (cpumask_test_cpu(best_cpu, p->cpus_ptr) && dl_time_before(dl_se->deadline, cp->elements[0].dl)) { if (later_mask) cpumask_set_cpu(best_cpu, later_mask); diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 962cf343f798..636ca6f88c8e 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -196,14 +196,17 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, * based on the task model parameters and gives the minimal utilization * required to meet deadlines. */ -unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs, - unsigned long max, enum schedutil_type type) +unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs, + unsigned long max, enum schedutil_type type, + struct task_struct *p) { unsigned long dl_util, util, irq; struct rq *rq = cpu_rq(cpu); - if (type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) + if (!IS_BUILTIN(CONFIG_UCLAMP_TASK) && + type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) { return max; + } /* * Early check to see if IRQ/steal time saturates the CPU, can be @@ -219,9 +222,16 @@ unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs, * 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. + * + * CFS and RT utilization can be boosted or capped, depending on + * utilization clamp constraints requested by currently RUNNABLE + * tasks. + * When there are no CFS RUNNABLE tasks, clamps are released and + * frequency will be gracefully reduced with the utilization decay. */ - util = util_cfs; - util += cpu_util_rt(rq); + util = util_cfs + cpu_util_rt(rq); + if (type == FREQUENCY_UTIL) + util = uclamp_util_with(rq, util, p); dl_util = cpu_util_dl(rq); @@ -276,12 +286,12 @@ static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) { struct rq *rq = cpu_rq(sg_cpu->cpu); unsigned long util = cpu_util_cfs(rq); - unsigned long max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu); + unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu); sg_cpu->max = max; sg_cpu->bw_dl = cpu_bw_dl(rq); - return schedutil_freq_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL); + return schedutil_cpu_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL, NULL); } /** diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c index 9c6480e6d62d..b7abca987d94 100644 --- a/kernel/sched/cpupri.c +++ b/kernel/sched/cpupri.c @@ -94,11 +94,11 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p, if (skip) continue; - if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids) + if (cpumask_any_and(p->cpus_ptr, vec->mask) >= nr_cpu_ids) continue; if (lowest_mask) { - cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask); + cpumask_and |