From 295d6d5e373607729bcc8182c25afe964655714f Mon Sep 17 00:00:00 2001 From: Luca Abeni Date: Thu, 7 Sep 2017 12:09:29 +0200 Subject: sched/deadline: Fix switching to -deadline Fix a bug introduced in: 72f9f3fdc928 ("sched/deadline: Remove dl_new from struct sched_dl_entity") After that commit, when switching to -deadline if the scheduling deadline of a task is in the past then switched_to_dl() calls setup_new_entity() to properly initialize the scheduling deadline and runtime. The problem is that the task is enqueued _before_ having its parameters initialized by setup_new_entity(), and this can cause problems. For example, a task with its out-of-date deadline in the past will potentially be enqueued as the highest priority one; however, its adjusted deadline may not be the earliest one. This patch fixes the problem by initializing the task's parameters before enqueuing it. Signed-off-by: luca abeni Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Daniel Bristot de Oliveira Cc: Juri Lelli Cc: Linus Torvalds Cc: Mathieu Poirier Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1504778971-13573-3-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'kernel/sched/deadline.c') diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 0191ec7667c3..9d45354e4296 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1364,6 +1364,10 @@ enqueue_dl_entity(struct sched_dl_entity *dl_se, update_dl_entity(dl_se, pi_se); } else if (flags & ENQUEUE_REPLENISH) { replenish_dl_entity(dl_se, pi_se); + } else if ((flags & ENQUEUE_RESTORE) && + dl_time_before(dl_se->deadline, + rq_clock(rq_of_dl_rq(dl_rq_of_se(dl_se))))) { + setup_new_dl_entity(dl_se); } __enqueue_dl_entity(dl_se); @@ -2255,13 +2259,6 @@ static void switched_to_dl(struct rq *rq, struct task_struct *p) return; } - /* - * If p is boosted we already updated its params in - * rt_mutex_setprio()->enqueue_task(..., ENQUEUE_REPLENISH), - * p's deadline being now already after rq_clock(rq). - */ - if (dl_time_before(p->dl.deadline, rq_clock(rq))) - setup_new_dl_entity(&p->dl); if (rq->curr != p) { #ifdef CONFIG_SMP -- cgit v1.2.3 From 8c0944cee7af55291df0b28e6e2eeac0930e93c9 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 7 Sep 2017 12:09:30 +0200 Subject: sched/deadline: Rename __dl_clear() to __dl_sub() __dl_sub() is more meaningful as a name, and is more consistent with the naming of the dual function (__dl_add()). Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Luca Abeni Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Daniel Bristot de Oliveira Cc: Juri Lelli Cc: Linus Torvalds Cc: Mathieu Poirier Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1504778971-13573-4-git-send-email-luca.abeni@santannapisa.it Signed-off-by: Ingo Molnar --- kernel/sched/deadline.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'kernel/sched/deadline.c') diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 9d45354e4296..8d1b946fa684 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -242,7 +242,7 @@ static void task_non_contending(struct task_struct *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_bw_cpus(task_cpu(p))); + __dl_sub(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); __dl_clear_params(p); raw_spin_unlock(&dl_b->lock); } @@ -1209,7 +1209,7 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer) } raw_spin_lock(&dl_b->lock); - __dl_clear(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); + __dl_sub(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); raw_spin_unlock(&dl_b->lock); __dl_clear_params(p); @@ -2170,7 +2170,7 @@ static void set_cpus_allowed_dl(struct task_struct *p, * until we complete the update. */ raw_spin_lock(&src_dl_b->lock); - __dl_clear(src_dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); + __dl_sub(src_dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p))); raw_spin_unlock(&src_dl_b->lock); } @@ -2448,7 +2448,7 @@ int sched_dl_overflow(struct task_struct *p, int policy, if (dl_policy(policy) && !task_has_dl_policy(p) && !__dl_overflow(dl_b, cpus, 0, new_bw)) { if (hrtimer_active(&p->dl.inactive_timer)) - __dl_clear(dl_b, p->dl.dl_bw, cpus); + __dl_sub(dl_b, p->dl.dl_bw, cpus); __dl_add(dl_b, new_bw, cpus); err = 0; } else if (dl_policy(policy) && task_has_dl_policy(p) && @@ -2460,7 +2460,7 @@ int sched_dl_overflow(struct task_struct *p, int policy, * But this would require to set the task's "inactive * timer" when the task is not inactive. */ - __dl_clear(dl_b, p->dl.dl_bw, cpus); + __dl_sub(dl_b, p->dl.dl_bw, cpus); __dl_add(dl_b, new_bw, cpus); dl_change_utilization(p, new_bw); err = 0; -- cgit v1.2.3