diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-04-14 15:12:00 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-04-14 15:12:04 +0200 |
commit | 4cbb62148cd686c2d3618861deb15eeb83744405 (patch) | |
tree | ae20584f1375ee80a419d0cc60a7cde8c5cf9cea /kernel/sched | |
parent | 668ce0ac707719d866af7e432e518af7b4c575ad (diff) | |
parent | 8d3d5ada56a692d36a9d55858881147ec10cfeb6 (diff) |
Merge branch 'tip/sched/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into sched/core
Pull a scheduler optimization commit from Steven Rostedt.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r-- | kernel/sched/rt.c | 56 |
1 files changed, 26 insertions, 30 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 44af55e6d5d0..c5565c3c515f 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1803,44 +1803,40 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p) static void set_cpus_allowed_rt(struct task_struct *p, const struct cpumask *new_mask) { - int weight = cpumask_weight(new_mask); + struct rq *rq; + int weight; BUG_ON(!rt_task(p)); - /* - * Update the migration status of the RQ if we have an RT task - * which is running AND changing its weight value. - */ - if (p->on_rq && (weight != p->rt.nr_cpus_allowed)) { - struct rq *rq = task_rq(p); - - if (!task_current(rq, p)) { - /* - * Make sure we dequeue this task from the pushable list - * before going further. It will either remain off of - * the list because we are no longer pushable, or it - * will be requeued. - */ - if (p->rt.nr_cpus_allowed > 1) - dequeue_pushable_task(rq, p); + if (!p->on_rq) + return; - /* - * Requeue if our weight is changing and still > 1 - */ - if (weight > 1) - enqueue_pushable_task(rq, p); + weight = cpumask_weight(new_mask); - } + /* + * Only update if the process changes its state from whether it + * can migrate or not. + */ + if ((p->rt.nr_cpus_allowed > 1) == (weight > 1)) + return; - if ((p->rt.nr_cpus_allowed <= 1) && (weight > 1)) { - rq->rt.rt_nr_migratory++; - } else if ((p->rt.nr_cpus_allowed > 1) && (weight <= 1)) { - BUG_ON(!rq->rt.rt_nr_migratory); - rq->rt.rt_nr_migratory--; - } + rq = task_rq(p); - update_rt_migration(&rq->rt); + /* + * The process used to be able to migrate OR it can now migrate + */ + if (weight <= 1) { + if (!task_current(rq, p)) + dequeue_pushable_task(rq, p); + BUG_ON(!rq->rt.rt_nr_migratory); + rq->rt.rt_nr_migratory--; + } else { + if (!task_current(rq, p)) + enqueue_pushable_task(rq, p); + rq->rt.rt_nr_migratory++; } + + update_rt_migration(&rq->rt); } /* Assumes rq->lock is held */ |