]> bbs.cooldavid.org Git - net-next-2.6.git/blobdiff - kernel/sched.c
Merge branch 'linus' into sched/core
[net-next-2.6.git] / kernel / sched.c
index 49d2fa7b687a6cd9956e5d7179ab26822bcff6f1..52b7efd274167faf094605665ba37ca73f714804 100644 (file)
@@ -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;