diff options
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/core.c | 15 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 59 | ||||
| -rw-r--r-- | kernel/sched/rt.c | 14 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 4 |
4 files changed, 31 insertions, 61 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3026678113e7..d8a6196465d5 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -92,10 +92,13 @@ void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) { - if (hrtimer_active(period_timer)) - return; + /* + * Do not forward the expiration time of active timers; + * we do not want to loose an overrun. + */ + if (!hrtimer_active(period_timer)) + hrtimer_forward_now(period_timer, period); - hrtimer_forward_now(period_timer, period); hrtimer_start_expires(period_timer, HRTIMER_MODE_ABS_PINNED); } @@ -8113,10 +8116,8 @@ static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) __refill_cfs_bandwidth_runtime(cfs_b); /* restart the period timer (if active) to handle new period expiry */ - if (runtime_enabled && cfs_b->timer_active) { - /* force a reprogram */ - __start_cfs_bandwidth(cfs_b, true); - } + if (runtime_enabled) + start_cfs_bandwidth(cfs_b); raw_spin_unlock_irq(&cfs_b->lock); for_each_online_cpu(i) { diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 854881b2526b..e3b32ebfe421 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3476,16 +3476,7 @@ static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq) if (cfs_b->quota == RUNTIME_INF) amount = min_amount; else { - /* - * If the bandwidth pool has become inactive, then at least one - * period must have elapsed since the last consumption. - * Refresh the global state and ensure bandwidth timer becomes - * active. - */ - if (!cfs_b->timer_active) { - __refill_cfs_bandwidth_runtime(cfs_b); - __start_cfs_bandwidth(cfs_b, false); - } + start_cfs_bandwidth(cfs_b); if (cfs_b->runtime > 0) { amount = min(cfs_b->runtime, min_amount); @@ -3634,6 +3625,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); struct sched_entity *se; long task_delta, dequeue = 1; + bool empty; se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))]; @@ -3663,13 +3655,21 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq) cfs_rq->throttled = 1; cfs_rq->throttled_clock = rq_clock(rq); raw_spin_lock(&cfs_b->lock); + empty = list_empty(&cfs_rq->throttled_list); + /* * Add to the _head_ of the list, so that an already-started * distribute_cfs_runtime will not see us */ list_add_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq); - if (!cfs_b->timer_active) - __start_cfs_bandwidth(cfs_b, false); + + /* + * If we're the first throttled task, make sure the bandwidth + * timer is running. + */ + if (empty) + start_cfs_bandwidth(cfs_b); + raw_spin_unlock(&cfs_b->lock); } @@ -3784,13 +3784,6 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) if (cfs_b->idle && !throttled) goto out_deactivate; - /* - * if we have relooped after returning idle once, we need to update our - * status as actually running, so that other cpus doing - * __start_cfs_bandwidth will stop trying to cancel us. - */ - cfs_b->timer_active = 1; - __refill_cfs_bandwidth_runtime(cfs_b); if (!throttled) { @@ -3835,7 +3828,6 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) return 0; out_deactivate: - cfs_b->timer_active = 0; return 1; } @@ -3999,6 +3991,7 @@ static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer) { struct cfs_bandwidth *cfs_b = container_of(timer, struct cfs_bandwidth, slack_timer); + do_sched_cfs_slack_timer(cfs_b); return HRTIMER_NORESTART; @@ -4008,15 +4001,12 @@ static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) { struct cfs_bandwidth *cfs_b = container_of(timer, struct cfs_bandwidth, period_timer); - ktime_t now; int overrun; int idle = 0; raw_spin_lock(&cfs_b->lock); for (;;) { - now = hrtimer_cb_get_time(timer); - overrun = hrtimer_forward(timer, now, cfs_b->period); - + overrun = hrtimer_forward_now(timer, cfs_b->period); if (!overrun) break; @@ -4047,27 +4037,8 @@ static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) INIT_LIST_HEAD(&cfs_rq->throttled_list); } -/* requires cfs_b->lock, may release to reprogram timer */ -void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force) +void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) { - /* - * The timer may be active because we're trying to set a new bandwidth - * period or because we're racing with the tear-down path - * (timer_active==0 becomes visible before the hrtimer call-back - * terminates). In either case we ensure that it's re-programmed - */ - while (unlikely(hrtimer_active(&cfs_b->period_timer)) && - hrtimer_try_to_cancel(&cfs_b->period_timer) < 0) { - /* bounce the lock to allow do_sched_cfs_period_timer to run */ - raw_spin_unlock(&cfs_b->lock); - cpu_relax(); - raw_spin_lock(&cfs_b->lock); - /* if someone else restarted the timer then we're done */ - if (!force && cfs_b->timer_active) - return; - } - - cfs_b->timer_active = 1; start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period); } diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 575da76a3874..b0febf25d8f1 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -18,19 +18,20 @@ static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) { struct rt_bandwidth *rt_b = container_of(timer, struct rt_bandwidth, rt_period_timer); - ktime_t now; - int overrun; int idle = 0; + int overrun; + raw_spin_lock(&rt_b->rt_runtime_lock); for (;;) { - now = hrtimer_cb_get_time(timer); - overrun = hrtimer_forward(timer, now, rt_b->rt_period); - + overrun = hrtimer_forward_now(timer, rt_b->rt_period); if (!overrun) break; + raw_spin_unlock(&rt_b->rt_runtime_lock); idle = do_sched_rt_period_timer(rt_b, overrun); + raw_spin_lock(&rt_b->rt_runtime_lock); } + raw_spin_unlock(&rt_b->rt_runtime_lock); return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; } @@ -52,9 +53,6 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b) if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) return; - if (hrtimer_active(&rt_b->rt_period_timer)) - return; - raw_spin_lock(&rt_b->rt_runtime_lock); start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period); raw_spin_unlock(&rt_b->rt_runtime_lock); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index e0e129993958..08606a1f8c4d 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -215,7 +215,7 @@ struct cfs_bandwidth { s64 hierarchical_quota; u64 runtime_expires; - int idle, timer_active; + int idle; struct hrtimer period_timer, slack_timer; struct list_head throttled_cfs_rq; @@ -306,7 +306,7 @@ extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); -extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force); +extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); extern void free_rt_sched_group(struct task_group *tg); |