From 8fd27231c3302e0c7e1907df1252db97b65eb241 Mon Sep 17 00:00:00 2001 From: Luca Abeni Date: Thu, 18 May 2017 22:13:34 +0200 Subject: [PATCH] sched/deadline: Track the "total rq utilization" too The total rq utilization is defined as the sum of the utilisations of tasks that are "assigned" to a runqueue, independently from their state (TASK_RUNNING or blocked) Tested-by: Daniel Bristot de Oliveira Signed-off-by: Luca Abeni Signed-off-by: Claudio Scordino Signed-off-by: Peter Zijlstra (Intel) Cc: Joel Fernandes Cc: Juri Lelli Cc: Linus Torvalds Cc: Mathieu Poirier Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Tommaso Cucinotta Link: http://lkml.kernel.org/r/1495138417-6203-8-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 118 ++++++++++++++++++++++++++++------------ kernel/sched/sched.h | 11 ++++ 2 files changed, 95 insertions(+), 34 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 61ea3039cdc1..6c6a1f099d61 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -51,6 +51,7 @@ void add_running_bw(u64 dl_bw, struct dl_rq *dl_rq) lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); dl_rq->running_bw += dl_bw; SCHED_WARN_ON(dl_rq->running_bw < old); /* overflow */ + SCHED_WARN_ON(dl_rq->running_bw > dl_rq->this_bw); } static inline @@ -65,25 +66,52 @@ void sub_running_bw(u64 dl_bw, struct dl_rq *dl_rq) dl_rq->running_bw = 0; } +static inline +void add_rq_bw(u64 dl_bw, struct dl_rq *dl_rq) +{ + u64 old = dl_rq->this_bw; + + lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); + dl_rq->this_bw += dl_bw; + SCHED_WARN_ON(dl_rq->this_bw < old); /* overflow */ +} + +static inline +void sub_rq_bw(u64 dl_bw, struct dl_rq *dl_rq) +{ + u64 old = dl_rq->this_bw; + + lockdep_assert_held(&(rq_of_dl_rq(dl_rq))->lock); + dl_rq->this_bw -= dl_bw; + SCHED_WARN_ON(dl_rq->this_bw > old); /* underflow */ + if (dl_rq->this_bw > old) + dl_rq->this_bw = 0; + SCHED_WARN_ON(dl_rq->running_bw > dl_rq->this_bw); +} + void dl_change_utilization(struct task_struct *p, u64 new_bw) { - if (task_on_rq_queued(p)) - return; + struct rq *rq; - if (!p->dl.dl_non_contending) + if (task_on_rq_queued(p)) return; - sub_running_bw(p->dl.dl_bw, &task_rq(p)->dl); - p->dl.dl_non_contending = 0; - /* - * If the timer handler is currently running and the - * timer cannot be cancelled, inactive_task_timer() - * will see that dl_not_contending is not set, and - * will not touch the rq's active utilization, - * so we are still safe. - */ - if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) - put_task_struct(p); + rq = task_rq(p); + if (p->dl.dl_non_contending) { + sub_running_bw(p->dl.dl_bw, &rq->dl); + p->dl.dl_non_contending = 0; + /* + * If the timer handler is currently running and the + * timer cannot be cancelled, inactive_task_timer() + * will see that dl_not_contending is not set, and + * will not touch the rq's active utilization, + * so we are still safe. + */ + if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) + put_task_struct(p); + } + sub_rq_bw(p->dl.dl_bw, &rq->dl); + add_rq_bw(new_bw, &rq->dl); } /* @@ -178,6 +206,8 @@ static void task_non_contending(struct task_struct *p) if (!dl_task(p) || p->state == TASK_DEAD) { struct dl_bw *dl_b = dl_bw_of(task_cpu(p)); + if (p->state == TASK_DEAD) + sub_rq_bw(p->dl.dl_bw, &rq->dl); raw_spin_lock(&dl_b->lock); __dl_clear(dl_b, p->dl.dl_bw); __dl_clear_params(p); @@ -192,7 +222,7 @@ static void task_non_contending(struct task_struct *p) hrtimer_start(timer, ns_to_ktime(zerolag_time), HRTIMER_MODE_REL); } -static void task_contending(struct sched_dl_entity *dl_se) +static void task_contending(struct sched_dl_entity *dl_se, int flags) { struct dl_rq *dl_rq = dl_rq_of_se(dl_se); @@ -203,6 +233,9 @@ static void task_contending(struct sched_dl_entity *dl_se) if (dl_se->dl_runtime == 0) return; + if (flags & ENQUEUE_MIGRATED) + add_rq_bw(dl_se->dl_bw, dl_rq); + if (dl_se->dl_non_contending) { dl_se->dl_non_contending = 0; /* @@ -268,6 +301,7 @@ void init_dl_rq(struct dl_rq *dl_rq) #endif dl_rq->running_bw = 0; + dl_rq->this_bw = 0; init_dl_rq_bw_ratio(dl_rq); } @@ -1042,6 +1076,7 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) if (p->state == TASK_DEAD && dl_se->dl_non_contending) { sub_running_bw(p->dl.dl_bw, dl_rq_of_se(&p->dl)); + sub_rq_bw(p->dl.dl_bw, dl_rq_of_se(&p->dl)); dl_se->dl_non_contending = 0; } @@ -1207,7 +1242,7 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se, * we want a replenishment of its runtime. */ if (flags & ENQUEUE_WAKEUP) { - task_contending(dl_se); + task_contending(dl_se, flags); update_dl_entity(dl_se, pi_se); } else if (flags & ENQUEUE_REPLENISH) { replenish_dl_entity(dl_se, pi_se); @@ -1260,8 +1295,10 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) if (!p->dl.dl_throttled && dl_is_constrained(&p->dl)) dl_check_constrained_dl(&p->dl); - if (p->on_rq == TASK_ON_RQ_MIGRATING || flags & ENQUEUE_RESTORE) + if (p->on_rq == TASK_ON_RQ_MIGRATING || flags & ENQUEUE_RESTORE) { + add_rq_bw(p->dl.dl_bw, &rq->dl); add_running_bw(p->dl.dl_bw, &rq->dl); + } /* * If p is throttled, we do not enqueue it. In fact, if it exhausted @@ -1277,7 +1314,7 @@ static void enqueue_task_dl(struct rq *rq, struct task_struct *p, int flags) */ if (p->dl.dl_throttled && !(flags & ENQUEUE_REPLENISH)) { if (flags & ENQUEUE_WAKEUP) - task_contending(&p->dl); + task_contending(&p->dl, flags); return; } @@ -1299,8 +1336,10 @@ static void dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags) update_curr_dl(rq); __dequeue_task_dl(rq, p, flags); - if (p->on_rq == TASK_ON_RQ_MIGRATING || flags & DEQUEUE_SAVE) + if (p->on_rq == TASK_ON_RQ_MIGRATING || flags & DEQUEUE_SAVE) { sub_running_bw(p->dl.dl_bw, &rq->dl); + sub_rq_bw(p->dl.dl_bw, &rq->dl); + } /* * This check allows to start the inactive timer (or to immediately @@ -1394,7 +1433,7 @@ static void migrate_task_rq_dl(struct task_struct *p) { struct rq *rq; - if (!(p->state == TASK_WAKING) || !(p->dl.dl_non_contending)) + if (p->state != TASK_WAKING) return; rq = task_rq(p); @@ -1404,18 +1443,20 @@ static void migrate_task_rq_dl(struct task_struct *p) * rq->lock is not... So, lock it */ raw_spin_lock(&rq->lock); - sub_running_bw(p->dl.dl_bw, &rq->dl); - p->dl.dl_non_contending = 0; - /* - * If the timer handler is currently running and the - * timer cannot be cancelled, inactive_task_timer() - * will see that dl_not_contending is not set, and - * will not touch the rq's active utilization, - * so we are still safe. - */ - if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) - put_task_struct(p); - + if (p->dl.dl_non_contending) { + sub_running_bw(p->dl.dl_bw, &rq->dl); + p->dl.dl_non_contending = 0; + /* + * If the timer handler is currently running and the + * timer cannot be cancelled, inactive_task_timer() + * will see that dl_not_contending is not set, and + * will not touch the rq's active utilization, + * so we are still safe. + */ + if (hrtimer_try_to_cancel(&p->dl.inactive_timer) == 1) + put_task_struct(p); + } + sub_rq_bw(p->dl.dl_bw, &rq->dl); raw_spin_unlock(&rq->lock); } @@ -1858,7 +1899,9 @@ retry: deactivate_task(rq, next_task, 0); sub_running_bw(next_task->dl.dl_bw, &rq->dl); + sub_rq_bw(next_task->dl.dl_bw, &rq->dl); set_task_cpu(next_task, later_rq->cpu); + add_rq_bw(next_task->dl.dl_bw, &later_rq->dl); add_running_bw(next_task->dl.dl_bw, &later_rq->dl); activate_task(later_rq, next_task, 0); ret = 1; @@ -1948,7 +1991,9 @@ static void pull_dl_task(struct rq *this_rq) deactivate_task(src_rq, p, 0); sub_running_bw(p->dl.dl_bw, &src_rq->dl); + sub_rq_bw(p->dl.dl_bw, &src_rq->dl); set_task_cpu(p, this_cpu); + add_rq_bw(p->dl.dl_bw, &this_rq->dl); add_running_bw(p->dl.dl_bw, &this_rq->dl); activate_task(this_rq, p, 0); dmin = p->dl.deadline; @@ -2057,6 +2102,9 @@ static void switched_from_dl(struct rq *rq, struct task_struct *p) if (task_on_rq_queued(p) && p->dl.dl_runtime) task_non_contending(p); + if (!task_on_rq_queued(p)) + sub_rq_bw(p->dl.dl_bw, &rq->dl); + /* * We cannot use inactive_task_timer() to invoke sub_running_bw() * at the 0-lag time, because the task could have been migrated @@ -2086,9 +2134,11 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) put_task_struct(p); /* If p is not queued we will update its parameters at next wakeup. */ - if (!task_on_rq_queued(p)) - return; + if (!task_on_rq_queued(p)) { + add_rq_bw(p->dl.dl_bw, &rq->dl); + return; + } /* * If p is boosted we already updated its params in * rt_mutex_setprio()->enqueue_task(..., ENQUEUE_REPLENISH), diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 878fe757d6ad..b7321dac03c1 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -566,6 +566,17 @@ struct dl_rq { */ u64 running_bw; + /* + * Utilization of the tasks "assigned" to this runqueue (including + * the tasks that are in runqueue and the tasks that executed on this + * CPU and blocked). Increased when a task moves to this runqueue, and + * decreased when the task moves away (migrates, changes scheduling + * policy, or terminates). + * This is needed to compute the "inactive utilization" for the + * runqueue (inactive utilization = this_bw - running_bw). + */ + u64 this_bw; + /* * Inverse of the fraction of CPU utilization that can be reclaimed * by the GRUB algorithm. -- 2.20.1