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-rw-r--r--include/linux/sched.h54
-rw-r--r--kernel/sched.c145
-rw-r--r--kernel/sched_debug.c103
-rw-r--r--kernel/sched_fair.c189
-rw-r--r--kernel/sched_features.h55
-rw-r--r--kernel/sched_rt.c2
-rw-r--r--kernel/time/tick-sched.c3
-rw-r--r--kernel/user.c2
8 files changed, 166 insertions, 387 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index dad7f668ebf7..43c945152732 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -275,11 +275,17 @@ extern cpumask_var_t nohz_cpu_mask;
#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
extern int select_nohz_load_balancer(int cpu);
extern int get_nohz_load_balancer(void);
+extern int nohz_ratelimit(int cpu);
#else
static inline int select_nohz_load_balancer(int cpu)
{
return 0;
}
+
+static inline int nohz_ratelimit(int cpu)
+{
+ return 0;
+}
#endif
/*
@@ -1077,36 +1083,8 @@ struct load_weight {
unsigned long weight, inv_weight;
};
-/*
- * CFS stats for a schedulable entity (task, task-group etc)
- *
- * Current field usage histogram:
- *
- * 4 se->block_start
- * 4 se->run_node
- * 4 se->sleep_start
- * 6 se->load.weight
- */
-struct sched_entity {
- struct load_weight load; /* for load-balancing */
- struct rb_node run_node;
- struct list_head group_node;
- unsigned int on_rq;
-
- u64 exec_start;
- u64 sum_exec_runtime;
- u64 vruntime;
- u64 prev_sum_exec_runtime;
-
- u64 last_wakeup;
- u64 avg_overlap;
-
- u64 nr_migrations;
-
- u64 start_runtime;
- u64 avg_wakeup;
-
#ifdef CONFIG_SCHEDSTATS
+struct sched_statistics {
u64 wait_start;
u64 wait_max;
u64 wait_count;
@@ -1138,6 +1116,24 @@ struct sched_entity {
u64 nr_wakeups_affine_attempts;
u64 nr_wakeups_passive;
u64 nr_wakeups_idle;
+};
+#endif
+
+struct sched_entity {
+ struct load_weight load; /* for load-balancing */
+ struct rb_node run_node;
+ struct list_head group_node;
+ unsigned int on_rq;
+
+ u64 exec_start;
+ u64 sum_exec_runtime;
+ u64 vruntime;
+ u64 prev_sum_exec_runtime;
+
+ u64 nr_migrations;
+
+#ifdef CONFIG_SCHEDSTATS
+ struct sched_statistics statistics;
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
diff --git a/kernel/sched.c b/kernel/sched.c
index 49d2fa7b687a..52b7efd27416 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -492,8 +492,11 @@ struct rq {
#define CPU_LOAD_IDX_MAX 5
unsigned long cpu_load[CPU_LOAD_IDX_MAX];
#ifdef CONFIG_NO_HZ
+ u64 nohz_stamp;
unsigned char in_nohz_recently;
#endif
+ unsigned int skip_clock_update;
+
/* capture load from *all* tasks on this cpu: */
struct load_weight load;
unsigned long nr_load_updates;
@@ -591,6 +594,13 @@ static inline
void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
{
rq->curr->sched_class->check_preempt_curr(rq, p, flags);
+
+ /*
+ * A queue event has occurred, and we're going to schedule. In
+ * this case, we can save a useless back to back clock update.
+ */
+ if (test_tsk_need_resched(p))
+ rq->skip_clock_update = 1;
}
static inline int cpu_of(struct rq *rq)
@@ -625,7 +635,8 @@ static inline int cpu_of(struct rq *rq)
inline void update_rq_clock(struct rq *rq)
{
- rq->clock = sched_clock_cpu(cpu_of(rq));
+ if (!rq->skip_clock_update)
+ rq->clock = sched_clock_cpu(cpu_of(rq));
}
/*
@@ -1228,6 +1239,17 @@ void wake_up_idle_cpu(int cpu)
if (!tsk_is_polling(rq->idle))
smp_send_reschedule(cpu);
}
+
+int nohz_ratelimit(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ u64 diff = rq->clock - rq->nohz_stamp;
+
+ rq->nohz_stamp = rq->clock;
+
+ return diff < (NSEC_PER_SEC / HZ) >> 1;
+}
+
#endif /* CONFIG_NO_HZ */
static u64 sched_avg_period(void)
@@ -1770,8 +1792,6 @@ static void double_rq_lock(struct rq *rq1, struct rq *rq2)
raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
}
}
- update_rq_clock(rq1);
- update_rq_clock(rq2);
}
/*
@@ -1868,9 +1888,7 @@ static void update_avg(u64 *avg, u64 sample)
static void
enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head)
{
- if (wakeup)
- p->se.start_runtime = p->se.sum_exec_runtime;
-
+ update_rq_clock(rq);
sched_info_queued(p);
p->sched_class->enqueue_task(rq, p, wakeup, head);
p->se.on_rq = 1;
@@ -1878,17 +1896,7 @@ enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head)
static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep)
{
- if (sleep) {
- if (p->se.last_wakeup) {
- update_avg(&p->se.avg_overlap,
- p->se.sum_exec_runtime - p->se.last_wakeup);
- p->se.last_wakeup = 0;
- } else {
- update_avg(&p->se.avg_wakeup,
- sysctl_sched_wakeup_granularity);
- }
- }
-
+ update_rq_clock(rq);
sched_info_dequeued(p);
p->sched_class->dequeue_task(rq, p, sleep);
p->se.on_rq = 0;
@@ -2361,14 +2369,10 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
unsigned long flags;
struct rq *rq;
- if (!sched_feat(SYNC_WAKEUPS))
- wake_flags &= ~WF_SYNC;
-
this_cpu = get_cpu();
smp_wmb();
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
if (!(p->state & state))
goto out;
@@ -2409,7 +2413,6 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
rq = cpu_rq(cpu);
raw_spin_lock(&rq->lock);
- update_rq_clock(rq);
/*
* We migrated the task without holding either rq->lock, however
@@ -2437,34 +2440,18 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
out_activate:
#endif /* CONFIG_SMP */
- schedstat_inc(p, se.nr_wakeups);
+ schedstat_inc(p, se.statistics.nr_wakeups);
if (wake_flags & WF_SYNC)
- schedstat_inc(p, se.nr_wakeups_sync);
+ schedstat_inc(p, se.statistics.nr_wakeups_sync);
if (orig_cpu != cpu)
- schedstat_inc(p, se.nr_wakeups_migrate);
+ schedstat_inc(p, se.statistics.nr_wakeups_migrate);
if (cpu == this_cpu)
- schedstat_inc(p, se.nr_wakeups_local);
+ schedstat_inc(p, se.statistics.nr_wakeups_local);
else
- schedstat_inc(p, se.nr_wakeups_remote);
+ schedstat_inc(p, se.statistics.nr_wakeups_remote);
activate_task(rq, p, 1);
success = 1;
- /*
- * Only attribute actual wakeups done by this task.
- */
- if (!in_interrupt()) {
- struct sched_entity *se = &current->se;
- u64 sample = se->sum_exec_runtime;
-
- if (se->last_wakeup)
- sample -= se->last_wakeup;
- else
- sample -= se->start_runtime;
- update_avg(&se->avg_wakeup, sample);
-
- se->last_wakeup = se->sum_exec_runtime;
- }
-
out_running:
trace_sched_wakeup(rq, p, success);
check_preempt_curr(rq, p, wake_flags);
@@ -2526,42 +2513,9 @@ static void __sched_fork(struct task_struct *p)
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
p->se.nr_migrations = 0;
- p->se.last_wakeup = 0;
- p->se.avg_overlap = 0;
- p->se.start_runtime = 0;
- p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.wait_max = 0;
- p->se.wait_count = 0;
- p->se.wait_sum = 0;
-
- p->se.sleep_start = 0;
- p->se.sleep_max = 0;
- p->se.sum_sleep_runtime = 0;
-
- p->se.block_start = 0;
- p->se.block_max = 0;
- p->se.exec_max = 0;
- p->se.slice_max = 0;
-
- p->se.nr_migrations_cold = 0;
- p->se.nr_failed_migrations_affine = 0;
- p->se.nr_failed_migrations_running = 0;
- p->se.nr_failed_migrations_hot = 0;
- p->se.nr_forced_migrations = 0;
-
- p->se.nr_wakeups = 0;
- p->se.nr_wakeups_sync = 0;
- p->se.nr_wakeups_migrate = 0;
- p->se.nr_wakeups_local = 0;
- p->se.nr_wakeups_remote = 0;
- p->se.nr_wakeups_affine = 0;
- p->se.nr_wakeups_affine_attempts = 0;
- p->se.nr_wakeups_passive = 0;
- p->se.nr_wakeups_idle = 0;
-
+ memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
INIT_LIST_HEAD(&p->rt.run_list);
@@ -2675,7 +2629,6 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
BUG_ON(p->state != TASK_WAKING);
p->state = TASK_RUNNING;
- update_rq_clock(rq);
activate_task(rq, p, 0);
trace_sched_wakeup_new(rq, p, 1);
check_preempt_curr(rq, p, WF_FORK);
@@ -3629,23 +3582,9 @@ static inline void schedule_debug(struct task_struct *prev)
static void put_prev_task(struct rq *rq, struct task_struct *prev)
{
- if (prev->state == TASK_RUNNING) {
- u64 runtime = prev->se.sum_exec_runtime;
-
- runtime -= prev->se.prev_sum_exec_runtime;
- runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
-
- /*
- * In order to avoid avg_overlap growing stale when we are
- * indeed overlapping and hence not getting put to sleep, grow
- * the avg_overlap on preemption.
- *
- * We use the average preemption runtime because that
- * correlates to the amount of cache footprint a task can
- * build up.
- */
- update_avg(&prev->se.avg_overlap, runtime);
- }
+ if (prev->se.on_rq)
+ update_rq_clock(rq);
+ rq->skip_clock_update = 0;
prev->sched_class->put_prev_task(rq, prev);
}
@@ -3708,7 +3647,6 @@ need_resched_nonpreemptible:
hrtick_clear(rq);
raw_spin_lock_irq(&rq->lock);
- update_rq_clock(rq);
clear_tsk_need_resched(prev);
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
@@ -4265,7 +4203,6 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
BUG_ON(prio < 0 || prio > MAX_PRIO);
rq = task_rq_lock(p, &flags);
- update_rq_clock(rq);
oldprio = p->prio;
prev_class = p->sched_class;
@@ -4308,7 +4245,6 @@ void set_user_nice(struct task_struct *p, long nice)
* the task might be in the middle of scheduling on another CPU.
*/
rq = task_rq_lock(p, &flags);
- 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
@@ -4591,7 +4527,6 @@ recheck:
raw_spin_unlock_irqrestore(&p->pi_lock, flags);
goto recheck;
}
- update_rq_clock(rq);
on_rq = p->se.on_rq;
running = task_current(rq, p);
if (on_rq)
@@ -5602,7 +5537,6 @@ void sched_idle_next(void)
__setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1);
- update_rq_clock(rq);
activate_task(rq, p, 0);
raw_spin_unlock_irqrestore(&rq->lock, flags);
@@ -5657,7 +5591,6 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
for ( ; ; ) {
if (!rq->nr_running)
break;
- update_rq_clock(rq);
next = pick_next_task(rq);
if (!next)
break;
@@ -5941,7 +5874,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
rq->migration_thread = NULL;
/* Idle task back to normal (off runqueue, low prio) */
raw_spin_lock_irq(&rq->lock);
- update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0);
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
@@ -7891,7 +7823,6 @@ static void normalize_task(struct rq *rq, struct task_struct *p)
{
int on_rq;
- update_rq_clock(rq);
on_rq = p->se.on_rq;
if (on_rq)
deactivate_task(rq, p, 0);
@@ -7918,9 +7849,9 @@ void normalize_rt_tasks(void)
p->se.exec_start = 0;
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_start = 0;
- p->se.sleep_start = 0;
- p->se.block_start = 0;
+ p->se.statistics.wait_start = 0;
+ p->se.statistics.sleep_start = 0;
+ p->se.statistics.block_start = 0;
#endif
if (!rt_task(p)) {
@@ -8253,8 +8184,6 @@ void sched_move_task(struct task_struct *tsk)
rq = task_rq_lock(tsk, &flags);
- update_rq_clock(rq);
-
running = task_current(rq, tsk);
on_rq = tsk->se.on_rq;
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 67f95aada4b9..8a46a719f367 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -70,16 +70,16 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu,
PN(se->vruntime);
PN(se->sum_exec_runtime);
#ifdef CONFIG_SCHEDSTATS
- PN(se->wait_start);
- PN(se->sleep_start);
- PN(se->block_start);
- PN(se->sleep_max);
- PN(se->block_max);
- PN(se->exec_max);
- PN(se->slice_max);
- PN(se->wait_max);
- PN(se->wait_sum);
- P(se->wait_count);
+ PN(se->statistics.wait_start);
+ PN(se->statistics.sleep_start);
+ PN(se->statistics.block_start);
+ PN(se->statistics.sleep_max);
+ PN(se->statistics.block_max);
+ PN(se->statistics.exec_max);
+ PN(se->statistics.slice_max);
+ PN(se->statistics.wait_max);
+ PN(se->statistics.wait_sum);
+ P(se->statistics.wait_count);
#endif
P(se->load.weight);
#undef PN
@@ -104,7 +104,7 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
SPLIT_NS(p->se.vruntime),
SPLIT_NS(p->se.sum_exec_runtime),
- SPLIT_NS(p->se.sum_sleep_runtime));
+ SPLIT_NS(p->se.statistics.sum_sleep_runtime));
#else
SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
@@ -407,40 +407,38 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.exec_start);
PN(se.vruntime);
PN(se.sum_exec_runtime);
- PN(se.avg_overlap);
- PN(se.avg_wakeup);
nr_switches = p->nvcsw + p->nivcsw;
#ifdef CONFIG_SCHEDSTATS
- PN(se.wait_start);
- PN(se.sleep_start);
- PN(se.block_start);
- PN(se.sleep_max);
- PN(se.block_max);
- PN(se.exec_max);
- PN(se.slice_max);
- PN(se.wait_max);
- PN(se.wait_sum);
- P(se.wait_count);
- PN(se.iowait_sum);
- P(se.iowait_count);
+ PN(se.statistics.wait_start);
+ PN(se.statistics.sleep_start);
+ PN(se.statistics.block_start);
+ PN(se.statistics.sleep_max);
+ PN(se.statistics.block_max);
+ PN(se.statistics.exec_max);
+ PN(se.statistics.slice_max);
+ PN(se.statistics.wait_max);
+ PN(se.statistics.wait_sum);
+ P(se.statistics.wait_count);
+ PN(se.statistics.iowait_sum);
+ P(se.statistics.iowait_count);
P(sched_info.bkl_count);
P(se.nr_migrations);
- P(se.nr_migrations_cold);
- P(se.nr_failed_migrations_affine);
- P(se.nr_failed_migrations_running);
- P(se.nr_failed_migrations_hot);
- P(se.nr_forced_migrations);
- P(se.nr_wakeups);
- P(se.nr_wakeups_sync);
- P(se.nr_wakeups_migrate);
- P(se.nr_wakeups_local);
- P(se.nr_wakeups_remote);
- P(se.nr_wakeups_affine);
- P(se.nr_wakeups_affine_attempts);
- P(se.nr_wakeups_passive);
- P(se.nr_wakeups_idle);
+ P(se.statistics.nr_migrations_cold);
+ P(se.statistics.nr_failed_migrations_affine);
+ P(se.statistics.nr_failed_migrations_running);
+ P(se.statistics.nr_failed_migrations_hot);
+ P(se.statistics.nr_forced_migrations);
+ P(se.statistics.nr_wakeups);
+ P(se.statistics.nr_wakeups_sync);
+ P(se.statistics.nr_wakeups_migrate);
+ P(se.statistics.nr_wakeups_local);
+ P(se.statistics.nr_wakeups_remote);
+ P(se.statistics.nr_wakeups_affine);
+ P(se.statistics.nr_wakeups_affine_attempts);
+ P(se.statistics.nr_wakeups_passive);
+ P(se.statistics.nr_wakeups_idle);
{
u64 avg_atom, avg_per_cpu;
@@ -491,32 +489,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
void proc_sched_set_task(struct task_struct *p)
{
#ifdef CONFIG_SCHEDSTATS
- p->se.wait_max = 0;
- p->se.wait_sum = 0;
- p->se.wait_count = 0;
- p->se.iowait_sum = 0;
- p->se.iowait_count = 0;
- p->se.sleep_max = 0;
- p->se.sum_sleep_runtime = 0;
- p->se.block_max = 0;
- p->se.exec_max = 0;
- p->se.slice_max = 0;
- p->se.nr_migrations = 0;
- p->se.nr_migrations_cold = 0;
- p->se.nr_failed_migrations_affine = 0;
- p->se.nr_failed_migrations_running = 0;
- p->se.nr_failed_migrations_hot = 0;
- p->se.nr_forced_migrations = 0;
- p->se.nr_wakeups = 0;
- p->se.nr_wakeups_sync = 0;
- p->se.nr_wakeups_migrate = 0;
- p->se.nr_wakeups_local = 0;
- p->se.nr_wakeups_remote = 0;
- p->se.nr_wakeups_affine = 0;
- p->se.nr_wakeups_affine_attempts = 0;
- p->se.nr_wakeups_passive = 0;
- p->se.nr_wakeups_idle = 0;
- p->sched_info.bkl_count = 0;
+ memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif
p->se.sum_exec_runtime = 0;
p->se.prev_sum_exec_runtime = 0;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5a5ea2cd924f..49ad99378f82 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -35,8 +35,8 @@
* (to see the precise effective timeslice length of your workload,
* run vmstat and monitor the context-switches (cs) field)
*/
-unsigned int sysctl_sched_latency = 5000000ULL;
-unsigned int normalized_sysctl_sched_latency = 5000000ULL;
+unsigned int sysctl_sched_latency = 6000000ULL;
+unsigned int normalized_sysctl_sched_latency = 6000000ULL;
/*
* The initial- and re-scaling of tunables is configurable
@@ -52,15 +52,15 @@ enum sched_tunable_scaling sysctl_sched_tunable_scaling
/*
* Minimal preemption granularity for CPU-bound tasks:
- * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ * (default: 2 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
-unsigned int sysctl_sched_min_granularity = 1000000ULL;
-unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL;
+unsigned int sysctl_sched_min_granularity = 2000000ULL;
+unsigned int normalized_sysctl_sched_min_granularity = 2000000ULL;
/*
* is kept at sysctl_sched_latency / sysctl_sched_min_granularity
*/
-static unsigned int sched_nr_latency = 5;
+static unsigned int sched_nr_latency = 3;
/*
* After fork, child runs first. If set to 0 (default) then
@@ -505,7 +505,8 @@ __update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
{
unsigned long delta_exec_weighted;
- schedstat_set(curr->exec_max, max((u64)delta_exec, curr->exec_max));
+ schedstat_set(curr->statistics.exec_max,
+ max((u64)delta_exec, curr->statistics.exec_max));
curr->sum_exec_runtime += delta_exec;
schedstat_add(cfs_rq, exec_clock, delta_exec);
@@ -548,7 +549,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
static inline void
update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- schedstat_set(se->wait_start, rq_of(cfs_rq)->clock);
+ schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock);
}
/*
@@ -567,18 +568,18 @@ static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
static void
update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
- schedstat_set(se->wait_max, max(se->wait_max,
- rq_of(cfs_rq)->clock - se->wait_start));
- schedstat_set(se->wait_count, se->wait_count + 1);
- schedstat_set(se->wait_sum, se->wait_sum +
- rq_of(cfs_rq)->clock - se->wait_start);
+ schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max,
+ rq_of(cfs_rq)->clock - se->statistics.wait_start));
+ schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1);
+ schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum +
+ rq_of(cfs_rq)->clock - se->statistics.wait_start);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
trace_sched_stat_wait(task_of(se),
- rq_of(cfs_rq)->clock - se->wait_start);
+ rq_of(cfs_rq)->clock - se->statistics.wait_start);
}
#endif
- schedstat_set(se->wait_start, 0);
+ schedstat_set(se->statistics.wait_start, 0);
}
static inline void
@@ -657,39 +658,39 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
if (entity_is_task(se))
tsk = task_of(se);
- if (se->sleep_start) {
- u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
+ if (se->statistics.sleep_start) {
+ u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start;
if ((s64)delta < 0)
delta = 0;
- if (unlikely(delta > se->sleep_max))
- se->sleep_max = delta;
+ if (unlikely(delta > se->statistics.sleep_max))
+ se->statistics.sleep_max = delta;
- se->sleep_start = 0;
- se->sum_sleep_runtime += delta;
+ se->statistics.sleep_start = 0;
+ se->statistics.sum_sleep_runtime += delta;
if (tsk) {
account_scheduler_latency(tsk, delta >> 10, 1);
trace_sched_stat_sleep(tsk, delta);
}
}
- if (se->block_start) {
- u64 delta = rq_of(cfs_rq)->clock - se->block_start;
+ if (se->statistics.block_start) {
+ u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start;
if ((s64)delta < 0)
delta = 0;
- if (unlikely(delta > se->block_max))
- se->block_max = delta;
+ if (unlikely(delta > se->statistics.block_max))
+ se->statistics.block_max = delta;
- se->block_start = 0;
- se->sum_sleep_runtime += delta;
+ se->statistics.block_start = 0;
+ se->statistics.sum_sleep_runtime += delta;
if (tsk) {
if (tsk->in_iowait) {
- se->iowait_sum += delta;
- se->iowait_count++;
+ se->statistics.iowait_sum += delta;
+ se->statistics.iowait_count++;
trace_sched_stat_iowait(tsk, delta);
}
@@ -737,20 +738,10 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
vruntime += sched_vslice(cfs_rq, se);
/* sleeps up to a single latency don't count. */
- if (!initial && sched_feat(FAIR_SLEEPERS)) {
+ if (!initial) {
unsigned long thresh = sysctl_sched_latency;
/*
- * Convert the sleeper threshold into virtual time.
- * SCHED_IDLE is a special sub-class. We care about
- * fairness only relative to other SCHED_IDLE tasks,
- * all of which have the same weight.
- */
- if (sched_feat(NORMALIZED_SLEEPER) && (!entity_is_task(se) ||
- task_of(se)->policy != SCHED_IDLE))
- thresh = calc_delta_fair(thresh, se);
-
- /*
* Halve their sleep time's effect, to allow
* for a gentler effect of sleepers:
*/
@@ -826,9 +817,9 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
struct task_struct *tsk = task_of(se);
if (tsk->state & TASK_INTERRUPTIBLE)
- se->sleep_start = rq_of(cfs_rq)->clock;
+ se->statistics.sleep_start = rq_of(cfs_rq)->clock;
if (tsk->state & TASK_UNINTERRUPTIBLE)
- se->block_start = rq_of(cfs_rq)->clock;
+ se->statistics.block_start = rq_of(cfs_rq)->clock;
}
#endif
}
@@ -912,7 +903,7 @@ set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
* when there are only lesser-weight tasks around):
*/
if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
- se->slice_max = max(se->slice_max,
+ se->statistics.slice_max = max(se->statistics.slice_max,
se->sum_exec_runtime - se->prev_sum_exec_runtime);
}
#endif
@@ -1240,7 +1231,6 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu,
static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
{
- struct task_struct *curr = current;
unsigned long this_load, load;
int idx, this_cpu, prev_cpu;
unsigned long tl_per_task;
@@ -1255,18 +1245,6 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
load = source_load(prev_cpu, idx);
this_load = target_load(this_cpu, idx);
- if (sync) {
- if (sched_feat(SYNC_LESS) &&
- (curr->se.avg_overlap > sysctl_sched_migration_cost ||
- p->se.avg_overlap > sysctl_sched_migration_cost))
- sync = 0;
- } else {
- if (sched_feat(SYNC_MORE) &&
- (curr->se.avg_overlap < sysctl_sched_migration_cost &&
- p->se.avg_overlap < sysctl_sched_migration_cost))
- sync = 1;
- }
-
/*
* If sync wakeup then subtract the (maximum possible)
* effect of the currently running task from the load
@@ -1306,7 +1284,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
if (sync && balanced)
return 1;
- schedstat_inc(p, se.nr_wakeups_affine_attempts);
+ schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
if (balanced ||
@@ -1318,7 +1296,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
* there is no bad imbalance.
*/
schedstat_inc(sd, ttwu_move_affine);
- schedstat_inc(p, se.nr_wakeups_affine);
+ schedstat_inc(p, se.statistics.nr_wakeups_affine);
return 1;
}
@@ -1451,13 +1429,12 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
int cpu = smp_processor_id();
int prev_cpu = task_cpu(p);
int new_cpu = cpu;
- int want_affine = 0;
+ int want_affine = 0, cpu_idle = !current->pid;
int want_sd = 1;
int sync = wake_flags & WF_SYNC;
if (sd_flag & SD_BALANCE_WAKE) {
- if (sched_feat(AFFINE_WAKEUPS) &&
- cpumask_test_cpu(cpu, &p->cpus_allowed))
+ if (cpumask_test_cpu(cpu, &p->cpus_allowed))
want_affine = 1;
new_cpu = prev_cpu;
}
@@ -1509,13 +1486,15 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
* If there's an idle sibling in this domain, make that
* the wake_affine target instead of the current cpu.
*/
- if (tmp->flags & SD_SHARE_PKG_RESOURCES)
+ if (!cpu_idle && tmp->flags & SD_SHARE_PKG_RESOURCES)
target = select_idle_sibling(p, tmp, target);
if (target >= 0) {
if (tmp->flags & SD_WAKE_AFFINE) {
affine_sd = tmp;
want_affine = 0;
+ if (target != cpu)
+ cpu_idle = 1;
}
cpu = target;
}
@@ -1531,6 +1510,7 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
sd = tmp;
}
+#ifdef CONFIG_FAIR_GROUP_SCHED
if (sched_feat(LB_SHARES_UPDATE)) {
/*
* Pick the largest domain to update shares over
@@ -1544,9 +1524,12 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
if (tmp)
update_shares(tmp);
}
+#endif
- if (affine_sd && wake_affine(affine_sd, p, sync))
- return cpu;
+ if (affine_sd) {
+ if (cpu_idle || cpu == prev_cpu || wake_affine(affine_sd, p, sync))
+ return cpu;
+ }
while (sd) {
int load_idx = sd->forkexec_idx;
@@ -1591,63 +1574,26 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
}
#endif /* CONFIG_SMP */
-/*
- * Adaptive granularity
- *
- * se->avg_wakeup gives the average time a task runs until it does a wakeup,
- * with the limit of wakeup_gran -- when it never does a wakeup.
- *
- * So the smaller avg_wakeup is the faster we want this task to preempt,
- * but we don't want to treat the preemptee unfairly and therefore allow it
- * to run for at least the amount of time we'd like to run.
- *
- * NOTE: we use 2*avg_wakeup to increase the probability of actually doing one
- *
- * NOTE: we use *nr_running to scale with load, this nicely matches the
- * degrading latency on load.
- */
-static unsigned long
-adaptive_gran(struct sched_entity *curr, struct sched_entity *se)
-{
- u64 this_run = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
- u64 expected_wakeup = 2*se->avg_wakeup * cfs_rq_of(se)->nr_running;
- u64 gran = 0;
-
- if (this_run < expected_wakeup)
- gran = expected_wakeup - this_run;
-
- return min_t(s64, gran, sysctl_sched_wakeup_granularity);
-}
-
static unsigned long
wakeup_gran(struct sched_entity *curr, struct sched_entity *se)
{
unsigned long gran = sysctl_sched_wakeup_granularity;
- if (cfs_rq_of(curr)->curr && sched_feat(ADAPTIVE_GRAN))
- gran = adaptive_gran(curr, se);
-
/*
* Since its curr running now, convert the gran from real-time
* to virtual-time in his units.
+ *
+ * By using 'se' instead of 'curr' we penalize light tasks, so
+ * they get preempted easier. That is, if 'se' < 'curr' then
+ * the resulting gran will be larger, therefore penalizing the
+ * lighter, if otoh 'se' > 'curr' then the resulting gran will
+ * be smaller, again penalizing the lighter task.
+ *
+ * This is especially important for buddies when the leftmost
+ * task is higher priority than the buddy.
*/
- if (sched_feat(ASYM_GRAN)) {
- /*
- * By using 'se' instead of 'curr' we penalize light tasks, so
- * they get preempted easier. That is, if 'se' < 'curr' then
- * the resulting gran will be larger, therefore penalizing the
- * lighter, if otoh 'se' > 'curr' then the resulting gran will
- * be smaller, again penalizing the lighter task.
- *
- * This is especially important for buddies when the leftmost
- * task is higher priority than the buddy.
- */
- if (unlikely(se->load.weight != NICE_0_LOAD))
- gran = calc_delta_fair(gran, se);
- } else {
- if (unlikely(curr->load.weight != NICE_0_LOAD))
- gran = calc_delta_fair(gran, curr);
- }
+ if (unlikely(se->load.weight != NICE_0_LOAD))
+ gran = calc_delta_fair(gran, se);
return gran;
}
@@ -1705,7 +1651,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
struct task_struct *curr = rq->curr;
struct sched_entity *se = &curr->se, *pse = &p->se;
struct cfs_rq *cfs_rq = task_cfs_rq(curr);
- int sync = wake_flags & WF_SYNC;
int scale = cfs_rq->nr_running >= sched_nr_latency;
if (unlikely(rt_prio(p->prio)))
@@ -1738,14 +1683,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
if (unlikely(curr->policy == SCHED_IDLE))
goto preempt;
- if (sched_feat(WAKEUP_SYNC) && sync)
- goto preempt;
-
- if (sched_feat(WAKEUP_OVERLAP) &&
- se->avg_overlap < sysctl_sched_migration_cost &&
- pse->avg_overlap < sysctl_sched_migration_cost)
- goto preempt;
-
if (!sched_feat(WAKEUP_PREEMPT))
return;
@@ -1844,13 +1781,13 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
* 3) are cache-hot on their current CPU.
*/
if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) {
- schedstat_inc(p, se.nr_failed_migrations_affine);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
return 0;
}
*all_pinned = 0;
if (task_running(rq, p)) {
- schedstat_inc(p, se.nr_failed_migrations_running);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_running);
return 0;
}
@@ -1866,14 +1803,14 @@ int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
#ifdef CONFIG_SCHEDSTATS
if (tsk_cache_hot) {
schedstat_inc(sd, lb_hot_gained[idle]);
- schedstat_inc(p, se.nr_forced_migrations);
+ schedstat_inc(p, se.statistics.nr_forced_migrations);
}
#endif
return 1;
}
if (tsk_cache_hot) {
- schedstat_inc(p, se.nr_failed_migrations_hot);
+ schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
return 0;
}
return 1;
@@ -3112,8 +3049,6 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
/* move a task from busiest_rq to target_rq */
double_lock_balance(busiest_rq, target_rq);
- update_rq_clock(busiest_rq);
- update_rq_clock(target_rq);
/* Search for an sd spanning us and the target CPU. */
for_each_domain(target_cpu, sd) {
diff --git a/kernel/sched_features.h b/kernel/sched_features.h
index d5059fd761d9..83c66e8ad3ee 100644
--- a/kernel/sched_features.h
+++ b/kernel/sched_features.h
@@ -1,11 +1,4 @@
/*
- * Disregards a certain amount of sleep time (sched_latency_ns) and
- * considers the task to be running during that period. This gives it
- * a service deficit on wakeup, allowing it to run sooner.
- */
-SCHED_FEAT(FAIR_SLEEPERS, 1)
-
-/*
* Only give sleepers 50% of their service deficit. This allows
* them to run sooner, but does not allow tons of sleepers to
* rip the spread apart.
@@ -13,13 +6,6 @@ SCHED_FEAT(FAIR_SLEEPERS, 1)
SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1)
/*
- * By not normalizing the sleep time, heavy tasks get an effective
- * longer period, and lighter task an effective shorter period they
- * are considered running.
- */
-SCHED_FEAT(NORMALIZED_SLEEPER, 0)
-
-/*
* Place new tasks ahead so that they do not starve already running
* tasks
*/
@@ -31,37 +17,6 @@ SCHED_FEAT(START_DEBIT, 1)
SCHED_FEAT(WAKEUP_PREEMPT, 1)
/*
- * Compute wakeup_gran based on task behaviour, clipped to
- * [0, sched_wakeup_gran_ns]
- */
-SCHED_FEAT(ADAPTIVE_GRAN, 1)
-
-/*
- * When converting the wakeup granularity to virtual time, do it such
- * that heavier tasks preempting a lighter task have an edge.
- */
-SCHED_FEAT(ASYM_GRAN, 1)
-
-/*
- * Always wakeup-preempt SYNC wakeups, see SYNC_WAKEUPS.
- */
-SCHED_FEAT(WAKEUP_SYNC, 0)
-
-/*
- * Wakeup preempt based on task behaviour. Tasks that do not overlap
- * don't get preempted.
- */
-SCHED_FEAT(WAKEUP_OVERLAP, 0)
-
-/*
- * Use the SYNC wakeup hint, pipes and the likes use this to indicate
- * the remote end is likely to consume the data we just wrote, and
- * therefore has cache benefit from being placed on the same cpu, see
- * also AFFINE_WAKEUPS.
- */
-SCHED_FEAT(SYNC_WAKEUPS, 1)
-
-/*
* Based on load and program behaviour, see if it makes sense to place
* a newly woken task on the same cpu as the task that woke it --
* improve cache locality. Typically used with SYNC wakeups as
@@ -70,16 +25,6 @@ SCHED_FEAT(SYNC_WAKEUPS, 1)
SCHED_FEAT(AFFINE_WAKEUPS, 1)
/*
- * Weaken SYNC hint based on overlap
- */
-SCHED_FEAT(SYNC_LESS, 1)
-
-/*
- * Add SYNC hint based on overlap
- */
-SCHED_FEAT(SYNC_MORE, 0)
-
-/*
* Prefer to schedule the task we woke last (assuming it failed
* wakeup-preemption), since its likely going to consume data we
* touched, increases cache locality.
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index b5b920ae2ea7..012d69bb67c7 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -613,7 +613,7 @@ static void update_curr_rt(struct rq *rq)
if (unlikely((s64)delta_exec < 0))
delta_exec = 0;
- schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec));
+ schedstat_set(curr->se.statistics.exec_max, max(curr->se.statistics.exec_max, delta_exec));
curr->se.sum_exec_runtime += delta_exec;
account_group_exec_runtime(curr, delta_exec);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index f992762d7f51..f25735a767af 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -262,6 +262,9 @@ void tick_nohz_stop_sched_tick(int inidle)
goto end;
}
+ if (nohz_ratelimit(cpu))
+ goto end;
+
ts->idle_calls++;
/* Read jiffies and the time when jiffies were updated last */
do {
diff --git a/kernel/user.c b/kernel/user.c
index 766467b3bcb7..ec3b2229893b 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -178,8 +178,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
return up;
- put_user_ns(new->user_ns);
- kmem_cache_free(uid_cachep, new);
out_unlock:
return NULL;
}
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