diff options
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 108 | ||||
| -rw-r--r-- | kernel/sched/cpufreq.c | 4 | ||||
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 2 | ||||
| -rw-r--r-- | kernel/sched/deadline.c | 6 | ||||
| -rw-r--r-- | kernel/sched/debug.c | 4 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 474 | ||||
| -rw-r--r-- | kernel/sched/isolation.c | 2 | ||||
| -rw-r--r-- | kernel/sched/pelt.c | 45 | ||||
| -rw-r--r-- | kernel/sched/pelt.h | 114 | ||||
| -rw-r--r-- | kernel/sched/psi.c | 23 | ||||
| -rw-r--r-- | kernel/sched/rt.c | 6 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 56 | ||||
| -rw-r--r-- | kernel/sched/topology.c | 37 |
13 files changed, 610 insertions, 271 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a674c7db2f29..ead464a0f2e5 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -107,11 +107,12 @@ struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) * [L] ->on_rq * RELEASE (rq->lock) * - * If we observe the old CPU in task_rq_lock, the acquire of + * If we observe the old CPU in task_rq_lock(), the acquire of * the old rq->lock will fully serialize against the stores. * - * If we observe the new CPU in task_rq_lock, the acquire will - * pair with the WMB to ensure we must then also see migrating. + * If we observe the new CPU in task_rq_lock(), the address + * dependency headed by '[L] rq = task_rq()' and the acquire + * will pair with the WMB to ensure we then also see migrating. */ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { rq_pin_lock(rq, rf); @@ -180,6 +181,7 @@ static void update_rq_clock_task(struct rq *rq, s64 delta) if ((irq_delta + steal) && sched_feat(NONTASK_CAPACITY)) update_irq_load_avg(rq, irq_delta + steal); #endif + update_rq_clock_pelt(rq, delta); } void update_rq_clock(struct rq *rq) @@ -396,7 +398,7 @@ static bool set_nr_if_polling(struct task_struct *p) #endif #endif -void wake_q_add(struct wake_q_head *head, struct task_struct *task) +static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task) { struct wake_q_node *node = &task->wake_q; @@ -405,19 +407,60 @@ void wake_q_add(struct wake_q_head *head, struct task_struct *task) * its already queued (either by us or someone else) and will get the * wakeup due to that. * - * This cmpxchg() executes a full barrier, which pairs with the full - * barrier executed by the wakeup in wake_up_q(). + * In order to ensure that a pending wakeup will observe our pending + * state, even in the failed case, an explicit smp_mb() must be used. */ - if (cmpxchg(&node->next, NULL, WAKE_Q_TAIL)) - return; - - get_task_struct(task); + smp_mb__before_atomic(); + if (unlikely(cmpxchg_relaxed(&node->next, NULL, WAKE_Q_TAIL))) + return false; /* * The head is context local, there can be no concurrency. */ *head->lastp = node; head->lastp = &node->next; + return true; +} + +/** + * wake_q_add() - queue a wakeup for 'later' waking. + * @head: the wake_q_head to add @task to + * @task: the task to queue for 'later' wakeup + * + * Queue a task for later wakeup, most likely by the wake_up_q() call in the + * same context, _HOWEVER_ this is not guaranteed, the wakeup can come + * instantly. + * + * This function must be used as-if it were wake_up_process(); IOW the task + * must be ready to be woken at this location. + */ +void wake_q_add(struct wake_q_head *head, struct task_struct *task) +{ + if (__wake_q_add(head, task)) + get_task_struct(task); +} + +/** + * wake_q_add_safe() - safely queue a wakeup for 'later' waking. + * @head: the wake_q_head to add @task to + * @task: the task to queue for 'later' wakeup + * + * Queue a task for later wakeup, most likely by the wake_up_q() call in the + * same context, _HOWEVER_ this is not guaranteed, the wakeup can come + * instantly. + * + * This function must be used as-if it were wake_up_process(); IOW the task + * must be ready to be woken at this location. + * + * This function is essentially a task-safe equivalent to wake_q_add(). Callers + * that already hold reference to @task can call the 'safe' version and trust + * wake_q to do the right thing depending whether or not the @task is already + * queued for wakeup. + */ +void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task) +{ + if (!__wake_q_add(head, task)) + put_task_struct(task); } void wake_up_q(struct wake_q_head *head) @@ -915,7 +958,7 @@ static struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf, { lockdep_assert_held(&rq->lock); - p->on_rq = TASK_ON_RQ_MIGRATING; + WRITE_ONCE(p->on_rq, TASK_ON_RQ_MIGRATING); dequeue_task(rq, p, DEQUEUE_NOCLOCK); set_task_cpu(p, new_cpu); rq_unlock(rq, rf); @@ -2177,6 +2220,9 @@ static void __sched_fork(unsigned long clone_flags, struct task_struct *p) INIT_HLIST_HEAD(&p->preempt_notifiers); #endif +#ifdef CONFIG_COMPACTION + p->capture_control = NULL; +#endif init_numa_balancing(clone_flags, p); } @@ -2418,7 +2464,7 @@ void wake_up_new_task(struct task_struct *p) #endif rq = __task_rq_lock(p, &rf); update_rq_clock(rq); - post_init_entity_util_avg(&p->se); + post_init_entity_util_avg(p); activate_task(rq, p, ENQUEUE_NOCLOCK); p->on_rq = TASK_ON_RQ_QUEUED; @@ -5252,9 +5298,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, } #ifdef CONFIG_COMPAT_32BIT_TIME -COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval, - compat_pid_t, pid, - struct old_timespec32 __user *, interval) +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); @@ -5854,14 +5899,11 @@ void __init sched_init_smp(void) /* * There's no userspace yet to cause hotplug operations; hence all the * CPU masks are stable and all blatant races in the below code cannot - * happen. The hotplug lock is nevertheless taken to satisfy lockdep, - * but there won't be any contention on it. + * happen. */ - cpus_read_lock(); mutex_lock(&sched_domains_mutex); sched_init_domains(cpu_active_mask); mutex_unlock(&sched_domains_mutex); - cpus_read_unlock(); /* Move init over to a non-isolated CPU */ if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0) @@ -6149,6 +6191,34 @@ void ___might_sleep(const char *file, int line, int preempt_offset) add_taint(TAINT_WARN, LOCKDEP_STILL_OK); } EXPORT_SYMBOL(___might_sleep); + +void __cant_sleep(const char *file, int line, int preempt_offset) +{ + static unsigned long prev_jiffy; + + if (irqs_disabled()) + return; + + if (!IS_ENABLED(CONFIG_PREEMPT_COUNT)) + return; + + if (preempt_count() > preempt_offset) + return; + + if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) + return; + prev_jiffy = jiffies; + + printk(KERN_ERR "BUG: assuming atomic context at %s:%d\n", file, line); + printk(KERN_ERR "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", + in_atomic(), irqs_disabled(), + current->pid, current->comm); + + debug_show_held_locks(current); + dump_stack(); + add_taint(TAINT_WARN, LOCKDEP_STILL_OK); +} +EXPORT_SYMBOL_GPL(__cant_sleep); #endif #ifdef CONFIG_MAGIC_SYSRQ diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c index 22bd8980f32f..835671f0f917 100644 --- a/kernel/sched/cpufreq.c +++ b/kernel/sched/cpufreq.c @@ -48,8 +48,8 @@ EXPORT_SYMBOL_GPL(cpufreq_add_update_util_hook); * * Clear the update_util_data pointer for the given CPU. * - * Callers must use RCU-sched callbacks to free any memory that might be - * accessed via the old update_util_data pointer or invoke synchronize_sched() + * Callers must use RCU callbacks to free any memory that might be + * accessed via the old update_util_data pointer or invoke synchronize_rcu() * right after this function to avoid use-after-free. */ void cpufreq_remove_update_util_hook(int cpu) diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 033ec7c45f13..2efe629425be 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -859,7 +859,7 @@ static void sugov_stop(struct cpufreq_policy *policy) for_each_cpu(cpu, policy->cpus) cpufreq_remove_update_util_hook(cpu); - synchronize_sched(); + synchronize_rcu(); if (!policy->fast_switch_enabled) { irq_work_sync(&sg_policy->irq_work); diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index fb8b7b5d745d..6a73e41a2016 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1767,7 +1767,7 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) deadline_queue_push_tasks(rq); if (rq->curr->sched_class != &dl_sched_class) - update_dl_rq_load_avg(rq_clock_task(rq), rq, 0); + update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 0); return p; } @@ -1776,7 +1776,7 @@ static void put_prev_task_dl(struct rq *rq, struct task_struct *p) { update_curr_dl(rq); - update_dl_rq_load_avg(rq_clock_task(rq), rq, 1); + update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 1); if (on_dl_rq(&p->dl) && p->nr_cpus_allowed > 1) enqueue_pushable_dl_task(rq, p); } @@ -1793,7 +1793,7 @@ static void task_tick_dl(struct rq *rq, struct task_struct *p, int queued) { update_curr_dl(rq); - update_dl_rq_load_avg(rq_clock_task(rq), rq, 1); + update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 1); /* * Even when we have runtime, update_curr_dl() might have resulted in us * not being the leftmost task anymore. In that case NEED_RESCHED will diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index de3de997e245..8039d62ae36e 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -315,6 +315,7 @@ void register_sched_domain_sysctl(void) { static struct ctl_table *cpu_entries; static struct ctl_table **cpu_idx; + static bool init_done = false; char buf[32]; int i; @@ -344,7 +345,10 @@ void register_sched_domain_sysctl(void) if (!cpumask_available(sd_sysctl_cpus)) { if (!alloc_cpumask_var(&sd_sysctl_cpus, GFP_KERNEL)) return; + } + if (!init_done) { + init_done = true; /* init to possible to not have holes in @cpu_entries */ cpumask_copy(sd_sysctl_cpus, cpu_possible_mask); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 50aa2aba69bd..ea74d43924b2 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -248,13 +248,6 @@ const struct sched_class fair_sched_class; */ #ifdef CONFIG_FAIR_GROUP_SCHED - -/* cpu runqueue to which this cfs_rq is attached */ -static inline struct rq *rq_of(struct cfs_rq *cfs_rq) -{ - return cfs_rq->rq; -} - static inline struct task_struct *task_of(struct sched_entity *se) { SCHED_WARN_ON(!entity_is_task(se)); @@ -282,79 +275,103 @@ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) return grp->my_q; } -static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) +static inline bool list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) { - if (!cfs_rq->on_list) { - struct rq *rq = rq_of(cfs_rq); - int cpu = cpu_of(rq); + struct rq *rq = rq_of(cfs_rq); + int cpu = cpu_of(rq); + + if (cfs_rq->on_list) + return rq->tmp_alone_branch == &rq->leaf_cfs_rq_list; + + cfs_rq->on_list = 1; + + /* + * Ensure we either appear before our parent (if already + * enqueued) or force our parent to appear after us when it is + * enqueued. The fact that we always enqueue bottom-up + * reduces this to two cases and a special case for the root + * cfs_rq. Furthermore, it also means that we will always reset + * tmp_alone_branch either when the branch is connected + * to a tree or when we reach the top of the tree + */ + if (cfs_rq->tg->parent && + cfs_rq->tg->parent->cfs_rq[cpu]->on_list) { /* - * Ensure we either appear before our parent (if already - * enqueued) or force our parent to appear after us when it is - * enqueued. The fact that we always enqueue bottom-up - * reduces this to two cases and a special case for the root - * cfs_rq. Furthermore, it also means that we will always reset - * tmp_alone_branch either when the branch is connected - * to a tree or when we reach the beg of the tree + * If parent is already on the list, we add the child + * just before. Thanks to circular linked property of + * the list, this means to put the child at the tail + * of the list that starts by parent. */ - if (cfs_rq->tg->parent && - cfs_rq->tg->parent->cfs_rq[cpu]->on_list) { - /* - * If parent is already on the list, we add the child - * just before. Thanks to circular linked property of - * the list, this means to put the child at the tail - * of the list that starts by parent. - */ - list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list, - &(cfs_rq->tg->parent->cfs_rq[cpu]->leaf_cfs_rq_list)); - /* - * The branch is now connected to its tree so we can - * reset tmp_alone_branch to the beginning of the - * list. - */ - rq->tmp_alone_branch = &rq->leaf_cfs_rq_list; - } else if (!cfs_rq->tg->parent) { - /* - * cfs rq without parent should be put - * at the tail of the list. - */ - list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list, - &rq->leaf_cfs_rq_list); - /* - * We have reach the beg of a tree so we can reset - * tmp_alone_branch to the beginning of the list. - */ - rq->tmp_alone_branch = &rq->leaf_cfs_rq_list; - } else { - /* - * The parent has not already been added so we want to - * make sure that it will be put after us. - * tmp_alone_branch points to the beg of the branch - * where we will add parent. - */ - list_add_rcu(&cfs_rq->leaf_cfs_rq_list, - rq->tmp_alone_branch); - /* - * update tmp_alone_branch to points to the new beg - * of the branch - */ - rq->tmp_alone_branch = &cfs_rq->leaf_cfs_rq_list; - } + list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list, + &(cfs_rq->tg->parent->cfs_rq[cpu]->leaf_cfs_rq_list)); + /* + * The branch is now connected to its tree so we can + * reset tmp_alone_branch to the beginning of the + * list. + */ + rq->tmp_alone_branch = &rq->leaf_cfs_rq_list; + return true; + } - cfs_rq->on_list = 1; + if (!cfs_rq->tg->parent) { + /* + * cfs rq without parent should be put + * at the tail of the list. + */ + list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list, + &rq->leaf_cfs_rq_list); + /* + * We have reach the top of a tree so we can reset + * tmp_alone_branch to the beginning of the list. + */ + rq->tmp_alone_branch = &rq->leaf_cfs_rq_list; + return true; } + + /* + * The parent has not already been added so we want to + * make sure that it will be put after us. + * tmp_alone_branch points to the begin of the branch + * where we will add parent. + */ + list_add_rcu(&cfs_rq->leaf_cfs_rq_list, rq->tmp_alone_branch); + /* + * update tmp_alone_branch to points to the new begin + * of the branch + */ + rq->tmp_alone_branch = &cfs_rq->leaf_cfs_rq_list; + return false; } static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) { if (cfs_rq->on_list) { + struct rq *rq = rq_of(cfs_rq); + + /* + * With cfs_rq being unthrottled/throttled during an enqueue, + * it can happen the tmp_alone_branch points the a leaf that + * we finally want to del. In this case, tmp_alone_branch moves + * to the prev element but it will point to rq->leaf_cfs_rq_list + * at the end of the enqueue. + */ + if (rq->tmp_alone_branch == &cfs_rq->leaf_cfs_rq_list) + rq->tmp_alone_branch = cfs_rq->leaf_cfs_rq_list.prev; + list_del_rcu(&cfs_rq->leaf_cfs_rq_list); cfs_rq->on_list = 0; } } -/* Iterate through all leaf cfs_rq's on a runqueue: */ -#define for_each_leaf_cfs_rq(rq, cfs_rq) \ - list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list) +static inline void assert_list_leaf_cfs_rq(struct rq *rq) +{ + SCHED_WARN_ON(rq->tmp_alone_branch != &rq->leaf_cfs_rq_list); +} + +/* Iterate thr' all leaf cfs_rq's on a runqueue */ +#define for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) \ + list_for_each_entry_safe(cfs_rq, pos, &rq->leaf_cfs_rq_list, \ + leaf_cfs_rq_list) /* Do the two (enqueued) entities belong to the same group ? */ static inline struct cfs_rq * @@ -410,12 +427,6 @@ static inline struct task_struct *task_of(struct sched_entity *se) return container_of(se, struct task_struct, se); } -static inline struct rq *rq_of(struct cfs_rq *cfs_rq) -{ - return container_of(cfs_rq, struct rq, cfs); -} - - #define for_each_sched_entity(se) \ for (; se; se = NULL) @@ -438,16 +449,21 @@ static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) return NULL; } -static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) +static inline bool list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq) { + return true; } static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq) { } -#define for_each_leaf_cfs_rq(rq, cfs_rq) \ - for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL) +static inline void assert_list_leaf_cfs_rq(struct rq *rq) +{ +} + +#define for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) \ + for (cfs_rq = &rq->cfs, pos = NULL; cfs_rq; cfs_rq = pos) static inline struct sched_entity *parent_entity(struct sched_entity *se) { @@ -686,9 +702,8 @@ static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se) return calc_delta_fair(sched_slice(cfs_rq, se), se); } -#ifdef CONFIG_SMP #include "pelt.h" -#include "sched-pelt.h" +#ifdef CONFIG_SMP static int select_idle_sibling(struct task_struct *p, int prev_cpu, int cpu); static unsigned long task_h_load(struct task_struct *p); @@ -744,8 +759,9 @@ static void attach_entity_cfs_rq(struct sched_entity *se); * Finally, that extrapolated util_avg is clamped to the cap (util_avg_cap) * if util_avg > util_avg_cap. */ -void post_init_entity_util_avg(struct sched_entity *se) +void post_init_entity_util_avg(struct task_struct *p) { + struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); struct sched_avg *sa = &se->avg; long cpu_scale = arch_scale_cpu_capacity(NULL, cpu_of(rq_of(cfs_rq))); @@ -763,22 +779,19 @@ void post_init_entity_util_avg(struct sched_entity *se) } } - if (entity_is_task(se)) { - struct task_struct *p = task_of(se); - if (p->sched_class != &fair_sched_class) { - /* - * For !fair tasks do: - * - update_cfs_rq_load_avg(now, cfs_rq); - attach_entity_load_avg(cfs_rq, se, 0); - switched_from_fair(rq, p); - * - * such that the next switched_to_fair() has the - * expected state. - */ - se->avg.last_update_time = cfs_rq_clock_task(cfs_rq); - return; - } + if (p->sched_class != &fair_sched_class) { + /* + * For !fair tasks do: + * + update_cfs_rq_load_avg(now, cfs_rq); + attach_entity_load_avg(cfs_rq, se, 0); + switched_from_fair(rq, p); + * + * such that the next switched_to_fair() has the + * expected state. + */ + se->avg.last_update_time = cfs_rq_clock_pelt(cfs_rq); + return; } attach_entity_cfs_rq(se); @@ -788,7 +801,7 @@ void post_init_entity_util_avg(struct sched_entity *se) void init_entity_runnable_average(struct sched_entity *se) { } -void post_init_entity_util_avg(struct sched_entity *se) +void post_init_entity_util_avg(struct task_struct *p) { } static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) @@ -1035,7 +1048,7 @@ unsigned int sysctl_numa_balancing_scan_size = 256; unsigned int sysctl_numa_balancing_scan_delay = 1000; struct numa_group { - atomic_t refcount; + refcount_t refcount; spinlock_t lock; /* nr_tasks, tasks */ int nr_tasks; @@ -1104,7 +1117,7 @@ static unsigned int task_scan_start(struct task_struct *p) unsigned long shared = group_faults_shared(ng); unsigned long private = group_faults_priv(ng); - period *= atomic_read(&ng->refcount); + period *= refcount_read(&ng->refcount); period *= shared + 1; period /= private + shared + 1; } @@ -1127,7 +1140,7 @@ static unsigned int task_scan_max(struct task_struct *p) unsigned long private = group_faults_priv(ng); unsigned long period = smax; - period *= atomic_read(&ng->refcount); + period *= refcount_read(&ng->refcount); period *= shared + 1; period /= private + shared + 1; @@ -1160,7 +1173,7 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) /* New address space, reset the preferred nid */ if (!(clone_flags & CLONE_VM)) { - p->numa_preferred_nid = -1; + p->numa_preferred_nid = NUMA_NO_NODE; return; } @@ -1180,13 +1193,13 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) static void account_numa_enqueue(struct rq *rq, struct task_struct *p) { - rq->nr_numa_running += (p->numa_preferred_nid != -1); + rq->nr_numa_running += (p->numa_preferred_nid != NUMA_NO_NODE); rq->nr_preferred_running += (p->numa_preferred_nid == task_node(p)); } static void account_numa_dequeue(struct rq *rq, struct task_struct *p) { - rq->nr_numa_running -= (p->numa_preferred_nid != -1); + rq->nr_numa_running -= (p->numa_preferred_nid != NUMA_NO_NODE); rq->nr_preferred_running -= (p->numa_preferred_nid == task_node(p)); } @@ -1400,7 +1413,7 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page, * two full passes of the "multi-stage node selection" test that is * executed below. */ - if ((p->numa_preferred_nid == -1 || p->numa_scan_seq <= 4) && + if ((p->numa_preferred_nid == NUMA_NO_NODE || p->numa_scan_seq <= 4) && (cpupid_pid_unset(last_cpupid) || cpupid_match_pid(p, last_cpupid))) return true; @@ -1848,7 +1861,7 @@ static void numa_migrate_preferred(struct task_struct *p) unsigned long interval = HZ; /* This task has no NUMA fault statistics yet */ - if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults)) + if (unlikely(p->numa_preferred_nid == NUMA_NO_NODE || !p->numa_faults)) return; /* Periodically retry migrating the task to the preferred node */ @@ -2095,7 +2108,7 @@ static int preferred_group_nid(struct task_struct *p, int nid) static void task_numa_placement(struct task_struct *p) { - int seq, nid, max_nid = -1; + int seq, nid, max_nid = NUMA_NO_NODE; unsigned long max_faults = 0; unsigned long fault_types[2] = { 0, 0 }; unsigned long total_faults; @@ -2203,12 +2216,12 @@ static void task_numa_placement(struct task_struct *p) static inline int get_numa_group(struct numa_group *grp) { - return atomic_inc_not_zero(&grp->refcount); + return refcount_inc_not_zero(&grp->refcount); } static inline void put_numa_group(struct numa_group *grp) { - if (atomic_dec_and_test(&grp->refcount)) + if (refcount_dec_and_test(&grp->refcount)) kfree_rcu(grp, rcu); } @@ -2229,7 +2242,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, if (!grp) return; - atomic_set(&grp->refcount, 1); + refcount_set(&grp->refcount, 1); grp->active_nodes = 1; grp->max_faults_cpu = 0; spin_lock_init(&grp->lock); @@ -2638,7 +2651,8 @@ static void update_scan_period(struct task_struct *p, int new_cpu) * the preferred node. */ if (dst_nid == p->numa_preferred_nid || - (p->numa_preferred_nid != -1 && src_nid != p->numa_preferred_nid)) + (p->numa_preferred_nid != NUMA_NO_NODE && + src_nid != p->numa_preferred_nid)) return; } @@ -3122,7 +3136,7 @@ void set_task_rq_fair(struct sched_entity *se, p_last_update_time = prev->avg.last_update_time; n_last_update_time = next->avg.last_update_time; #endif - __update_load_avg_blocked_se(p_last_update_time, cpu_of(rq_of(prev)), se); + __update_load_avg_blocked_se(p_last_update_time, se); se->avg.last_update_time = n_last_update_time; } @@ -3257,11 +3271,11 @@ update_tg_cfs_runnable(struct cfs_rq *cfs_rq, struct sched_entity *se, struct cf /* * runnable_sum can't be lower than running_sum - * As running sum is scale with CPU capacity wehreas the runnable sum - * is not we rescale running_sum 1st + * Rescale running sum to be in the same range as runnable sum + * running_sum is in [0 : LOAD_AVG_MAX << SCHED_CAPACITY_SHIFT] + * runnable_sum is in [0 : LOAD_AVG_MAX] */ - running_sum = se->avg.util_sum / - arch_scale_cpu_capacity(NULL, cpu_of(rq_of(cfs_rq))); + running_sum = se->avg.util_sum >> SCHED_CAPACITY_SHIFT; runnable_sum = max(runnable_sum, running_sum); load_sum = (s64)se_weight(se) * runnable_sum; @@ -3364,7 +3378,7 @@ static inline void add_tg_cfs_propagate(struct cfs_rq *cfs_rq, long runnable_sum /** * update_cfs_rq_load_avg - update the cfs_rq's load/util averages - * @now: current time, as per cfs_rq_clock_task() + * @now: current time, as per cfs_rq_clock_pelt() * @cfs_rq: cfs_rq to update * * The cfs_rq avg is the direct sum of all its entities (blocked and runnable) @@ -3409,7 +3423,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq) decayed = 1; } - decayed |= __update_load_avg_cfs_rq(now, cpu_of(rq_of(cfs_rq)), cfs_rq); + decayed |= __update_load_avg_cfs_rq(now, cfs_rq); #ifndef CONFIG_64BIT smp_wmb(); @@ -3499,9 +3513,7 @@ static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s /* Update task and its cfs_rq load average */ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) { - u64 now = cfs_rq_clock_task(cfs_rq); - struct rq *rq = rq_of(cfs_rq); - int cpu = cpu_of(rq); + u64 now = cfs_rq_clock_pelt(cfs_rq); int decayed; /* @@ -3509,7 +3521,7 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s * track group sched_entity load average for task_h_load calc in migration */ if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD)) - __update_load_avg_se(now, cpu, cfs_rq, se); + __update_load_avg_se(now, cfs_rq, se); decayed = update_cfs_rq_load_avg(now, cfs_rq); decayed |= propagate_entity_load_avg(se); @@ -3561,7 +3573,7 @@ void sync_entity_load_avg(struct sched_entity *se) u64 last_update_time; last_update_time = cfs_rq_last_update_time(cfs_rq); - __update_load_avg_blocked_se(last_update_time, cpu_of(rq_of(cfs_rq)), se); + __update_load_avg_blocked_se(last_update_time, se); } /* @@ -3577,10 +3589,6 @@ void remove_entity_load_avg(struct sched_entity *se) * tasks cannot exit without having gone through wake_up_new_task() -> * post_init_entity_util_avg() which will have added things to the * cfs_rq, so we can remove unconditionally. - * - * Similarly for groups, they will have passed through - * post_init_entity_util_avg() before unregister_sched_fair_group() - * calls this. */ sync_entity_load_avg(se); @@ -3654,6 +3662,7 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep) { long last_ewma_diff; struct util_est ue; + int cpu; if (!sched_feat(UTIL_EST)) return; @@ -3688,6 +3697,14 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep) return; /* + * To avoid overestimation of actual task utilization, skip updates if + * we cannot grant there is idle time in this CPU. + */ + cpu = cpu_of(rq_of(cfs_rq)); + if (task_util(p) > capacity_orig_of(cpu)) + return; + + /* * Update Task's estimated utilization * * When *p completes an activation we can consolidate another sample @@ -4429,6 +4446,10 @@ static int tg_unthrottle_up(struct task_group *tg, void *data) /* adjust cfs_rq_clock_task() */ cfs_rq->throttled_clock_task_time += rq_clock_task(rq) - cfs_rq->throttled_clock_task; + + /* Add cfs_rq with already running entity in the list */ + if (cfs_rq->nr_running >= 1) + list_add_leaf_cfs_rq(cfs_rq); } return 0; @@ -4440,8 +4461,10 @@ static int tg_throttle_down(struct task_group *tg, void *data) struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)]; /* group is entering throttled state, stop time */ - if (!cfs_rq->throttle_count) + if (!cfs_rq->throttle_count) { cfs_rq->throttled_clock_task = rq_clock_task(rq); + list_del_leaf_cfs_rq(cfs_rq); + } cfs_rq->throttle_count++; return 0; @@ -4544,6 +4567,8 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq) break; } + assert_list_leaf_cfs_rq(rq); + if (!se) add_nr_running(rq, task_delta); @@ -4565,7 +4590,7 @@ static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b, struct rq *rq = rq_of(cfs_rq); struct rq_flags rf; - rq_lock(rq, &rf); + rq_lock_irqsave(rq, &rf); if (!cfs_rq_throttled(cfs_rq)) goto next; @@ -4582,7 +4607,7 @@ static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b, unthrottle_cfs_rq(cfs_rq); next: - rq_unlock(rq, &rf); + rq_unlock_irqrestore(rq, &rf); if (!remaining) break; @@ -4598,7 +4623,7 @@ next: * period the timer is deactivated until scheduling resumes; cfs_b->idle is * used to track this state. */ -static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) +static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun, unsigned long flags) { u64 runtime, runtime_expires; int throttled; @@ -4640,11 +4665,11 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) while (throttled && cfs_b->runtime > 0 && !cfs_b->distribute_running) { runtime = cfs_b->runtime; cfs_b->distribute_running = 1; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); /* we can't nest cfs_b->lock while distributing bandwidth */ runtime = distribute_cfs_runtime(cfs_b, runtime, runtime_expires); - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); cfs_b->distribute_running = 0; throttled = !list_empty(&cfs_b->throttled_cfs_rq); @@ -4753,17 +4778,18 @@ static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b) { u64 runtime = 0, slice = sched_cfs_bandwidth_slice(); + unsigned long flags; u64 expires; /* confirm we're still not at a refresh boundary */ - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); if (cfs_b->distribute_running) { - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); return; } if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) { - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); return; } @@ -4774,18 +4800,18 @@ static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b) if (runtime) cfs_b->distribute_running = 1; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); if (!runtime) return; runtime = distribute_cfs_runtime(cfs_b, runtime, expires); - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); if (expires == cfs_b->runtime_expires) lsub_positive(&cfs_b->runtime, runtime); cfs_b->distribute_running = 0; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); } /* @@ -4863,20 +4889,21 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) { struct cfs_bandwidth *cfs_b = container_of(timer, struct cfs_bandwidth, period_timer); + unsigned long flags; int overrun; int idle = 0; - raw_spin_lock(&cfs_b->lock); + raw_spin_lock_irqsave(&cfs_b->lock, flags); for (;;) { overrun = hrtimer_forward_now(timer, cfs_b->period); if (!overrun) break; - idle = do_sched_cfs_period_timer(cfs_b, overrun); + idle = do_sched_cfs_period_timer(cfs_b, overrun, flags); } if (idle) cfs_b->period_active = 0; - raw_spin_unlock(&cfs_b->lock); + raw_spin_unlock_irqrestore(&cfs_b->lock, flags); return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; } @@ -4986,6 +5013,12 @@ static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq) } #else /* CONFIG_CFS_BANDWIDTH */ + +static inline bool cfs_bandwidth_used(void) +{ + return false; +} + static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq) { return rq_clock_task(rq_of(cfs_rq)); @@ -5177,6 +5210,23 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) } + if (cfs_bandwidth_used()) { + /* + * When bandwidth control is enabled; the cfs_rq_throttled() + * breaks in the above iteration can result in incomplete + * leaf list maintenance, resulting in triggering the assertion + * below. + */ + for_each_sched_entity(se) { + cfs_rq = cfs_rq_of(se); + + if (list_add_leaf_cfs_rq(cfs_rq)) + break; + } + } + + assert_list_leaf_cfs_rq(rq); + hrtick_update(rq); } @@ -5556,11 +5606,6 @@ static unsigned long capacity_of(int cpu) return cpu_rq(cpu)->cpu_capacity; } -static unsigned long capacity_orig_of(int cpu) -{ - return cpu_rq(cpu)->cpu_capacity_orig; -} - static unsigned long cpu_avg_load_per_task(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -5980,6 +6025,7 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p #ifdef CONFIG_SCHED_SMT DEFINE_STATIC_KEY_FALSE(sched_smt_present); +EXPORT_SYMBOL_GPL(sched_smt_present); static inline void set_idle_cores(int cpu, int val) { @@ -6052,7 +6098,7 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int bool idle = true; for_each_cpu(cpu, cpu_smt_mask(core)) { - cpumask_clear_cpu(cpu, cpus); + __cpumask_clear_cpu(cpu, cpus); if (!available_idle_cpu(cpu)) idle = false; } @@ -6072,7 +6118,7 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int /* * Scan the local SMT mask for idle CPUs. */ -static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target) +static int select_idle_smt(struct task_struct *p, int target) { int cpu; @@ -6096,7 +6142,7 @@ static inline int select_idle_core(struct task_struct *p, struct sched_domain *s return -1; } -static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target) +static inline int select_idle_smt(struct task_struct *p, int target) { return -1; } @@ -6201,7 +6247,7 @@ static int select_idle_sibling(struct task_struct *p, int prev, int target) if ((unsigned)i < nr_cpumask_bits) return i; - i = select_idle_smt(p, sd, target); + i = select_idle_smt(p, target); if ((unsigned)i < nr_cpumask_bits) return i; @@ -6607,7 +6653,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f if (sd_flag & SD_BALANCE_WAKE) { record_wakee(p); - if (static_branch_unlikely(&sched_energy_present)) { + if (sched_energy_enabled()) { new_cpu = find_energy_efficient_cpu(p, prev_cpu); if (new_cpu >= 0) return new_cpu; @@ -7026,6 +7072,12 @@ idle: if (new_tasks > 0) goto again; + /* + * rq is about to be idle, check if we need to update the + * lost_idle_time of clock_pelt + */ + update_idle_rq_clock_pelt(rq); + return NULL; } @@ -7646,10 +7698,27 @@ static inline bool others_have_blocked(struct rq *rq) #ifdef CONFIG_FAIR_GROUP_SCHED +static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) +{ + if (cfs_rq->load.weight) + return false; + + if (cfs_rq->avg.load_sum) + return false; + + if (cfs_rq->avg.util_sum) + return false; + + if (cfs_rq->avg.runnable_load_sum) + return false; + + return true; +} + static void update_blocked_averages(int cpu) { struct rq *rq = cpu_rq(cpu); - struct cfs_rq *cfs_rq; + struct cfs_rq *cfs_rq, *pos; const struct sched_class *curr_class; struct rq_flags rf; bool done = true; @@ -7661,14 +7730,10 @@ static void update_blocked_averages(int cpu) * Iterates the task_group tree in a bottom up fashion, see * list_add_leaf_cfs_rq() for details. */ - for_each_leaf_cfs_rq(rq, cfs_rq) { + for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) { struct sched_entity *se; - /* throttled entities do not contribute to load */ - if (throttled_hierarchy(cfs_rq)) - continue; - - if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq)) + if (update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq)) update_tg_load_avg(cfs_rq, 0); /* Propagate pending load changes to the parent, if any: */ @@ -7676,14 +7741,21 @@ static void update_blocked_averages(int cpu) if (se && !skip_blocked_update(se)) update_load_avg(cfs_rq_of(se), se, 0); + /* + * There can be a lot of idle CPU cgroups. Don't let fully + * decayed cfs_rqs linger on the list. + */ + if (cfs_rq_is_decayed(cfs_rq)) + list_del_leaf_cfs_rq(cfs_rq); + /* Don't need periodic decay once load/util_avg are null */ if (cfs_rq_has_blocked(cfs_rq)) done = false; } curr_class = rq->curr->sched_class; - update_rt_rq_load_avg(rq_clock_task(rq), rq, curr_class == &rt_sched_class); - update_dl_rq_load_avg(rq_clock_task(rq), rq, curr_class == &dl_sched_class); + update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class); + update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class); update_irq_load_avg(rq, 0); /* Don't need periodic decay once load/util_avg are null */ if (others_have_blocked(rq)) @@ -7753,11 +7825,11 @@ static inline void update_blocked_averages(int cpu) rq_lock_irqsave(rq, &rf); update_rq_clock(rq); - update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq); + update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq); curr_class = rq->curr->sched_class; - update_rt_rq_load_avg(rq_clock_task(rq), rq, curr_class == &rt_sched_class); - update_dl_rq_load_avg(rq_clock_task(rq), rq, curr_class == &dl_sched_class); + update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class); + update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class); update_irq_load_avg(rq, 0); #ifdef CONFIG_NO_HZ_COMMON rq->last_blocked_load_update_tick = jiffies; @@ -8451,9 +8523,7 @@ static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds) if (sched_asym_prefer(busiest_cpu, env->dst_cpu)) return 0; - env->imbalance = DIV_ROUND_CLOSEST( - sds->busiest_stat.avg_load * sds->busiest_stat.group_capacity, - SCHED_CAPACITY_SCALE); + env->imbalance = sds->busiest_stat.group_load; return 1; } @@ -8635,7 +8705,7 @@ static struct sched_group *find_busiest_group(struct lb_env *env) */ update_sd_lb_stats(env, &sds); - if (static_branch_unlikely(&sched_energy_present)) { + if (sched_energy_enabled()) { struct root_domain *rd = env->dst_rq->rd; if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized)) @@ -8826,21 +8896,25 @@ static struct rq *find_busiest_queue(struct lb_env *env, */ #define MAX_PINNED_INTERVAL 512 -static int need_active_balance(struct lb_env *env) +static inline bool +asym_active_balance(struct lb_env *env) { - struct sched_domain *sd = env->sd; + /* + * ASYM_PACKING needs to force migrate tasks from busy but + * lower priority CPUs in order to pack all tasks in the + * highest priority CPUs. + */ + return env->idle != CPU_NOT_IDLE && (env->sd->flags & SD_ASYM_PACKING) && + sched_asym_prefer(env->dst_cpu, env->src_cpu); +} - if (env->idle == CPU_NEWLY_IDLE) { +static inline bool +voluntary_active_balance(struct lb_env *env) +{ + struct sched_domain *sd = env->sd; - /* - * ASYM_PACKING needs to force migrate tasks from busy but - * lower priority CPUs in order to pack all tasks in the - * highest priority CPUs. - */ - if ((sd->flags & SD_ASYM_PACKING) && - sched_asym_prefer(env->dst_cpu, env->src_cpu)) - return 1; - } + if (asym_active_balance(env)) + return 1; /* * The dst_cpu is idle and the src_cpu CPU has only 1 CFS task. @@ -8858,6 +8932,16 @@ static int need_active_balance(struct lb_env *env) if (env->src_grp_type == group_misfit_task) return 1; + return 0; +} + +static int need_active_balance(struct lb_env *env) +{ + struct sched_domain *sd = env->sd; + + if (voluntary_active_balance(env)) + return 1; + return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2); } @@ -9022,7 +9106,7 @@ more_balance: if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) { /* Prevent to re-select dst_cpu via env's CPUs */ - cpumask_clear_cpu(env.dst_cpu, env.cpus); + __cpumask_clear_cpu(env.dst_cpu, env.cpus); env.dst_rq = cpu_rq(env.new_dst_cpu); env.dst_cpu = env.new_dst_cpu; @@ -9049,7 +9133,7 @@ more_balance: /* All tasks on this runqueue were pinned by CPU affinity */ if (unlikely(env.flags & LBF_ALL_PINNED)) { - cpumask_clear_cpu(cpu_of(busiest), cpus); + __cpumask_clear_cpu(cpu_of(busiest), cpus); /* * Attempting to continue load balancing at the current * sched_domain level only makes sense if there are @@ -9119,7 +9203,7 @@ more_balance: } else sd->nr_balance_failed = 0; - if (likely(!active_balance)) { + if (likely(!active_balance) || voluntary_active_balance(&env)) { /* We were unbalanced, so reset the balancing interval */ sd->balance_interval = sd->min_interval; } else { @@ -9468,15 +9552,8 @@ static void kick_ilb(unsigned int flags) } /* - * Current heuristic for kicking the idle load balancer in the presence - * of an idle cpu in the system. - * - This rq has more than one task. - * - This rq has at least one CFS task and the capacity of the CPU is - * significantly reduced because of RT tasks or IRQs. - * - At parent of LLC scheduler domain level, this cpu's scheduler group has - * multiple busy cpu. - * - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler - * domain span are idle. + * Current decision point for kicking the idle load balancer in the presence + * of idle CPUs in the system. */ static void nohz_balancer_kick(struct rq *rq) { @@ -9518,8 +9595,13 @@ static void nohz_balancer_kick(struct rq *rq) sds = rcu_dereference(per_cpu(sd_llc_shared, cpu)); if (sds) { /* - * XXX: write a coherent comment on why we do this. - * See also: http://lkml.kernel.org/r/20111202010832.602203411@sbsiddha-desk.sc.intel.com + * If there is an imbalance between LLC domains (IOW we could + * increase the overall cache use), we need some less-loaded LLC + * domain to pull some load. Likewise, we may need to spread + * load within the current LLC domain (e.g. packed SMT cores but + * other CPUs are idle). We can't really know from here how busy + * the others are - so just get a nohz balance going if it looks + * like this LLC domain has tasks we could move. */ nr_busy = atomic_read(&sds->nr_busy_cpus); if (nr_busy > 1) { @@ -9532,7 +9614,7 @@ static void nohz_balancer_kick(struct rq *rq) sd = rcu_dereference(rq->sd); if (sd) { if ((rq->cfs.h_nr_running >= 1) && - check_cpu_capacity(rq, sd)) { + check_cpu_capacity(rq, sd)) { flags = NOHZ_KICK_MASK; goto unlock; } @@ -9540,11 +9622,7 @@ static void nohz_balancer_kick(struct rq *rq) sd = rcu_dereference(per_cpu(sd_asym_packing, cpu)); if (sd) { - for_each_cpu(i, sched_domain_span(sd)) { - if (i == cpu || - !cpumask_test_cpu(i, nohz.idle_cpus_mask)) - continue; - + for_each_cpu_and(i, sched_domain_span(sd), nohz.idle_cpus_mask) { if (sched_asym_prefer(i, cpu)) { flags = NOHZ_KICK_MASK; goto unlock; @@ -10545,10 +10623,10 @@ const struct sched_class fair_sched_class = { #ifdef CONFIG_SCHED_DEBUG void print_cfs_stats(struct seq_file *m, int cpu) { - struct cfs_rq *cfs_rq; + struct cfs_rq *cfs_rq, *pos; rcu_read_lock(); - for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq) + for_each_leaf_cfs_rq_safe(cpu_rq(cpu), cfs_rq, pos) print_cfs_rq(m, cpu, cfs_rq); rcu_read_unlock(); } diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index 81faddba9e20..b02d148e7672 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -80,7 +80,7 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags) cpumask_andnot(housekeeping_mask, cpu_possible_mask, non_housekeeping_mask); if (cpumask_empty(housekeeping_mask)) - cpumask_set_cpu(smp_processor_id(), housekeeping_mask); + __cpumask_set_cpu(smp_processor_id(), housekeeping_mask); } else { cpumask_var_t tmp; diff --git a/kernel/sched/pelt.c b/kernel/sched/pelt.c index 90fb5bc12ad4..befce29bd882 100644 --- a/kernel/sched/pelt.c +++ b/kernel/sched/pelt.c @@ -26,7 +26,6 @@ #include <linux/sched.h> #include "sched.h" -#include "sched-pelt.h" #include "pelt.h" /* @@ -106,16 +105,12 @@ static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3) * n=1 */ static __always_inline u32 -accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, +accumulate_sum(u64 delta, struct sched_avg *sa, unsigned long load, unsigned long runnable, int running) { - unsigned long scale_freq, scale_cpu; u32 contrib = (u32)delta; /* p == 0 -> delta < 1024 */ u64 periods; - scale_freq = arch_scale_freq_capacity(cpu); - scale_cpu = arch_scale_cpu_capacity(NULL, cpu); - delta += sa->period_contrib; periods = delta / 1024; /* A period is 1024us (~1ms) */ @@ -137,13 +132,12 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, } sa->period_contrib = delta; - contrib = cap_scale(contrib, scale_freq); if (load) sa->load_sum += load * contrib; if (runnable) sa->runnable_load_sum += runnable * contrib; if (running) - sa->util_sum += contrib * scale_cpu; + sa->util_sum += contrib << SCHED_CAPACITY_SHIFT; return periods; } @@ -177,7 +171,7 @@ accumulate_sum(u64 delta, int cpu, struct sched_avg *sa, * = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}] */ static __always_inline int -___update_load_sum(u64 now, int cpu, struct sched_avg *sa, +___update_load_sum(u64 now, struct sched_avg *sa, unsigned long load, unsigned long runnable, int running) { u64 delta; @@ -221,7 +215,7 @@ ___update_load_sum(u64 now, int cpu, struct sched_avg *sa, * Step 1: accumulate *_sum since last_update_time. If we haven't * crossed period boundaries, finish. */ - if (!accumulate_sum(delta, cpu, sa, load, runnable, running)) + if (!accumulate_sum(delta, sa, load, runnable, running)) return 0; return 1; @@ -267,9 +261,9 @@ ___update_load_avg(struct sched_avg *sa, unsigned long load, unsigned long runna * runnable_load_avg = \Sum se->avg.runable_load_avg */ -int __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se) +int __update_load_avg_blocked_se(u64 now, struct sched_entity *se) { - if (___update_load_sum(now, cpu, &se->avg, 0, 0, 0)) { + if (___update_load_sum(now, &se->avg, 0, 0, 0)) { ___update_load_avg(&se->avg, se_weight(se), se_runnable(se)); return 1; } @@ -277,9 +271,9 @@ int __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se) return 0; } -int __update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se) +int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se) { - if (___update_load_sum(now, cpu, &se->avg, !!se->on_rq, !!se->on_rq, + if (___update_load_sum(now, &se->avg, !!se->on_rq, !!se->on_rq, cfs_rq->curr == se)) { ___update_load_avg(&se->avg, se_weight(se), se_runnable(se)); @@ -290,9 +284,9 @@ int __update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_e return 0; } -int __update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq) +int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq) { - if (___update_load_sum(now, cpu, &cfs_rq->avg, + if (___update_load_sum(now, &cfs_rq->avg, scale_load_down(cfs_rq->load.weight), scale_load_down(cfs_rq->runnable_weight), cfs_rq->curr != NULL)) { @@ -317,7 +311,7 @@ int __update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq) int update_rt_rq_load_avg(u64 now, struct rq *rq, int running) { - if (___update_load_sum(now, rq->cpu, &rq->avg_rt, + if (___update_load_sum(now, &rq->avg_rt, running, running, running)) { @@ -340,7 +334,7 @@ int update_rt_rq_load_avg(u64 now, struct rq *rq, int running) int update_dl_rq_load_avg(u64 now, struct rq *rq, int running) { - if (___update_load_sum(now, rq->cpu, &rq->avg_dl, + if (___update_load_sum(now, &rq->avg_dl, running, running, running)) { @@ -365,22 +359,31 @@ int update_dl_rq_load_avg(u64 now, struct rq *rq, int running) 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 + * clock_task. Instead we directly scale the running time to + * reflect the real amount of computation + */ + running = cap_scale(running, arch_scale_freq_capacity(cpu_of(rq))); + running = cap_scale(running, arch_scale_cpu_capacity(NULL, cpu_of(rq))); + /* * We know the time that has been used by interrupt since last update * but we don't when. Let be pessimistic and assume that interrupt has * happened just before the update. This is not so far from reality * because interrupt will most probably wake up task and trig an update - * of rq clock during which the metric si updated. + * of rq clock during which the metric is updated. * We start to decay with normal context time and then we add the * interrupt context time. * We can safely remove running from rq->clock because * rq->clock += delta with delta >= running */ - ret = ___update_load_sum(rq->clock - running, rq->cpu, &rq->avg_irq, + ret = ___update_load_sum(rq->clock - running, &rq->avg_irq, 0, 0, 0); - ret += ___update_load_sum(rq->clock, rq->cpu, &rq->avg_irq, + ret += ___update_load_sum(rq->clock, &rq->avg_irq, 1, 1, 1); diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h index 7e56b489ff32..7489d5f56960 100644 --- a/kernel/sched/pelt.h +++ b/kernel/sched/pelt.h @@ -1,8 +1,9 @@ #ifdef CONFIG_SMP +#include "sched-pelt.h" -int __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se); -int __update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se); -int __update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq); +int __update_load_avg_blocked_se(u64 now, struct sched_entity *se); +int __update_load_avg_se(u64 now, struct cfs_rq *cfs_rq, struct sched_entity *se); +int __update_load_avg_cfs_rq(u64 now, struct cfs_rq *cfs_rq); int update_rt_rq_load_avg(u64 now, struct rq *rq, int running); int update_dl_rq_load_avg(u64 now, struct rq *rq, int running); @@ -42,6 +43,101 @@ static inline void cfs_se_util_change(struct sched_avg *avg) WRITE_ONCE(avg->util_est.enqueued, enqueued); } +/* + * The clock_pelt scales the time to reflect the effective amount of + * computation done during the running delta time but then sync back to + * clock_task when rq is idle. + * + * + * absolute time | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11|12|13|14|15|16 + * @ max capacity ------******---------------******--------------- + * @ half capacity ------************---------************--------- + * clock pelt | 1| 2| 3| 4| 7| 8| 9| 10| 11|14|15|16 + * + */ +static inline void update_rq_clock_pelt(struct rq *rq, s64 delta) +{ + if (unlikely(is_idle_task(rq->curr))) { + /* The rq is idle, we can sync to clock_task */ + rq->clock_pelt = rq_clock_task(rq); + return; + } + + /* + * When a rq runs at a lower compute capacity, it will need + * more time to do the same amount of work than at max + * capacity. In order to be invariant, we scale the delta to + * reflect how much work has been really done. + * Running longer results in stealing idle time that will + * disturb the load signal compared to max capacity. This + * stolen idle time will be automatically reflected when the + * rq will be idle and the clock will be synced with + * rq_clock_task. + */ + + /* + * Scale the elapsed time to reflect the real amount of + * computation + */ + delta = cap_scale(delta, arch_scale_cpu_capacity(NULL, cpu_of(rq))); + delta = cap_scale(delta, arch_scale_freq_capacity(cpu_of(rq))); + + rq->clock_pelt += delta; +} + +/* + * When rq becomes idle, we have to check if it has lost idle time + * because it was fully busy. A rq is fully used when the /Sum util_sum + * is greater or equal to: + * (LOAD_AVG_MAX - 1024 + rq->cfs.avg.period_contrib) << SCHED_CAPACITY_SHIFT; + * For optimization and computing rounding purpose, we don't take into account + * the position in the current window (period_contrib) and we use the higher + * bound of util_sum to decide. + */ +static inline void update_idle_rq_clock_pelt(struct rq *rq) +{ + u32 divider = ((LOAD_AVG_MAX - 1024) << SCHED_CAPACITY_SHIFT) - LOAD_AVG_MAX; + u32 util_sum = rq->cfs.avg.util_sum; + util_sum += rq->avg_rt.util_sum; + util_sum += rq->avg_dl.util_sum; + + /* + * Reflecting stolen time makes sense only if the idle + * phase would be present at max capacity. As soon as the + * utilization of a rq has reached the maximum value, it is + * considered as an always runnig rq without idle time to + * steal. This potential idle time is considered as lost in + * this case. We keep track of this lost idle time compare to + * rq's clock_task. + */ + if (util_sum >= divider) + rq->lost_idle_time += rq_clock_task(rq) - rq->clock_pelt; +} + +static inline u64 rq_clock_pelt(struct rq *rq) +{ + lockdep_assert_held(&rq->lock); + assert_clock_updated(rq); + + return rq->clock_pelt - rq->lost_idle_time; +} + +#ifdef CONFIG_CFS_BANDWIDTH +/* rq->task_clock normalized against any time this cfs_rq has spent throttled */ +static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) +{ + if (unlikely(cfs_rq->throttle_count)) + return cfs_rq->throttled_clock_task - cfs_rq->throttled_clock_task_time; + + return rq_clock_pelt(rq_of(cfs_rq)) - cfs_rq->throttled_clock_task_time; +} +#else +static inline u64 cfs_rq_clock_pelt(struct cfs_rq *cfs_rq) +{ + return rq_clock_pelt(rq_of(cfs_rq)); +} +#endif + #else static inline int @@ -67,6 +163,18 @@ update_irq_load_avg(struct rq *rq, u64 running) { return 0; } + +static inline u64 rq_clock_pelt(struct rq *rq) +{ + return rq_clock_task(rq); +} + +static inline void +update_rq_clock_pelt(struct rq *rq, s64 delta) { } + +static inline void +update_idle_rq_clock_pelt(struct rq *rq) { } + #endif diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index fe24de3fbc93..0e97ca9306ef 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -124,6 +124,7 @@ * sampling of the aggregate task states would be. */ +#include "../workqueue_internal.h" #include <linux/sched/loadavg.h> #include <linux/seq_file.h> #include <linux/proc_fs.h> @@ -321,7 +322,7 @@ static bool update_stats(struct psi_group *group) expires = group->next_update; if (now < expires) goto out; - if (now - expires > psi_period) + if (now - expires >= psi_period) missed_periods = div_u64(now - expires, psi_period); /* @@ -480,9 +481,6 @@ static void psi_group_change(struct psi_group *group, int cpu, groupc->tasks[t]++; write_seqcount_end(&groupc->seq); - - if (!delayed_work_pending(&group->clock_work)) - schedule_delayed_work(&group->clock_work, PSI_FREQ); } static struct psi_group *iterate_groups(struct task_struct *task, void **iter) @@ -513,6 +511,7 @@ void psi_task_change(struct task_struct *task, int clear, int set) { int cpu = task_cpu(task); struct psi_group *group; + bool wake_clock = true; void *iter = NULL; if (!task->pid) @@ -530,8 +529,22 @@ void psi_task_change(struct task_struct *task, int clear, int set) task->psi_flags &= ~clear; task->psi_flags |= set; - while ((group = iterate_groups(task, &iter))) + /* + * Periodic aggregation shuts off if there is a period of no + * task changes, so we wake it back up if necessary. However, + * don't do this if the task change is the aggregation worker + * itself going to sleep, or we'll ping-pong forever. + */ + if (unlikely((clear & TSK_RUNNING) && + (task->flags & PF_WQ_WORKER) && + wq_worker_last_func(task) == psi_update_work)) + wake_clock = false; + + while ((group = iterate_groups(task, &iter))) { psi_group_change(group, cpu, clear, set); + if (wake_clock && !delayed_work_pending(&group->clock_work)) + schedule_delayed_work(&group->clock_work, PSI_FREQ); + } } void psi_memstall_tick(struct task_struct *task, int cpu) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index e4f398ad9e73..90fa23d36565 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1587,7 +1587,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) * rt task */ if (rq->curr->sched_class != &rt_sched_class) - update_rt_rq_load_avg(rq_clock_task(rq), rq, 0); + update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 0); return p; } @@ -1596,7 +1596,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p) { update_curr_rt(rq); - update_rt_rq_load_avg(rq_clock_task(rq), rq, 1); + update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); /* * The previous task needs to be made eligible for pushing @@ -2325,7 +2325,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) struct sched_rt_entity *rt_se = &p->rt; update_curr_rt(rq); - update_rt_rq_load_avg(rq_clock_task(rq), rq, 1); + update_rt_rq_load_avg(rq_clock_pelt(rq), rq, 1); watchdog(rq, p); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index d04530bf251f..efa686eeff26 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -861,7 +861,10 @@ struct rq { unsigned int clock_update_flags; u64 clock; - u64 clock_task; + /* Ensure that all clocks are in the same cache line */ + u64 clock_task ____cacheline_aligned; + u64 clock_pelt; + unsigned long lost_idle_time; atomic_t nr_iowait; @@ -951,6 +954,22 @@ struct rq { #endif }; +#ifdef CONFIG_FAIR_GROUP_SCHED + +/* CPU runqueue to which this cfs_rq is attached */ +static inline struct rq *rq_of(struct cfs_rq *cfs_rq) +{ + return cfs_rq->rq; +} + +#else + +static inline struct rq *rq_of(struct cfs_rq *cfs_rq) +{ + return container_of(cfs_rq, struct rq, cfs); +} +#endif + static inline int cpu_of(struct rq *rq) { #ifdef CONFIG_SMP @@ -1260,7 +1279,7 @@ extern void sched_ttwu_pending(void); /* * The domain tree (rq->sd) is protected by RCU's quiescent state transition. - * See detach_destroy_domains: synchronize_sched for details. + * See destroy_sched_domains: call_rcu for details. * * The domain tree of any CPU may only be accessed from within * preempt-disabled sections. @@ -1460,9 +1479,9 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) */ smp_wmb(); #ifdef CONFIG_THREAD_INFO_IN_TASK - p->cpu = cpu; + WRITE_ONCE(p->cpu, cpu); #else - task_thread_info(p)->cpu = cpu; + WRITE_ONCE(task_thread_info(p)->cpu, cpu); #endif p->wake_cpu = cpu; #endif @@ -1563,7 +1582,7 @@ static inline int task_on_rq_queued(struct task_struct *p) static inline int task_on_rq_migrating(struct task_struct *p) { - return p->on_rq == TASK_ON_RQ_MIGRATING; + return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; } /* @@ -1781,7 +1800,7 @@ extern void init_dl_rq_bw_ratio(struct dl_rq *dl_rq); 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 sched_entity *se); +extern void post_init_entity_util_avg(struct task_struct *p); #ifdef CONFIG_NO_HZ_FULL extern bool sched_can_stop_tick(struct rq *rq); @@ -2211,6 +2230,13 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} # define arch_scale_freq_invariant() false #endif +#ifdef CONFIG_SMP +static inline unsigned long capacity_orig_of(int cpu) +{ + return cpu_rq(cpu)->cpu_capacity_orig; +} +#endif + #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL /** * enum schedutil_type - CPU utilization type @@ -2299,11 +2325,19 @@ unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned #endif #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) + #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus))) -#else + +DECLARE_STATIC_KEY_FALSE(sched_energy_present); + +static inline bool sched_energy_enabled(void) +{ + return static_branch_unlikely(&sched_energy_present); +} + +#else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ + #define perf_domain_span(pd) NULL -#endif +static inline bool sched_energy_enabled(void) { return false; } -#ifdef CONFIG_SMP -extern struct static_key_false sched_energy_present; -#endif +#endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 3f35ba1d8fde..ab7f371a3a17 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -201,11 +201,37 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) return 1; } -DEFINE_STATIC_KEY_FALSE(sched_energy_present); #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) +DEFINE_STATIC_KEY_FALSE(sched_energy_present); +unsigned int sysctl_sched_energy_aware = 1; DEFINE_MUTEX(sched_energy_mutex); bool sched_energy_update; +#ifdef CONFIG_PROC_SYSCTL +int sched_energy_aware_handler(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + int ret, state; + + if (write && !capable(CAP_SYS_ADMIN)) + return -EPERM; + + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + if (!ret && write) { + state = static_branch_unlikely(&sched_energy_present); + if (state != sysctl_sched_energy_aware) { + mutex_lock(&sched_energy_mutex); + sched_energy_update = 1; + rebuild_sched_domains(); + sched_energy_update = 0; + mutex_unlock(&sched_energy_mutex); + } + } + + return ret; +} +#endif + static void free_pd(struct perf_domain *pd) { struct perf_domain *tmp; @@ -322,6 +348,9 @@ static bool build_perf_domains(const struct cpumask *cpu_map) struct cpufreq_policy *policy; struct cpufreq_governor *gov; + if (!sysctl_sched_energy_aware) + goto free; + /* EAS is enabled for asymmetric CPU capacity topologies. */ if (!per_cpu(sd_asym_cpucapacity, cpu)) { if (sched_debug()) { @@ -442,7 +471,7 @@ void rq_attach_root(struct rq *rq, struct root_domain *rd) raw_spin_unlock_irqrestore(&rq->lock, flags); if (old_rd) - call_rcu_sched(&old_rd->rcu, free_rootdomain); + call_rcu(&old_rd->rcu, free_rootdomain); } void sched_get_rd(struct root_domain *rd) @@ -455,7 +484,7 @@ void sched_put_rd(struct root_domain *rd) if (!atomic_dec_and_test(&rd->refcount)) return; - call_rcu_sched(&rd->rcu, free_rootdomain); + call_rcu(&rd->rcu, free_rootdomain); } static int init_rootdomain(struct root_domain *rd) @@ -676,7 +705,7 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) } struct s_data { - struct sched_domain ** __percpu sd; + struct sched_domain * __percpu *sd; struct root_domain *rd; }; |