diff options
| author | Qais Yousef <qais.yousef@arm.com> | 2020-03-02 13:27:20 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-03-06 12:57:29 +0100 |
| commit | d94a9df49069ba8ff7c4aaeca1229e6471a01a15 (patch) | |
| tree | e0a26defbc73d537e6835649b01585520cdeb568 | |
| parent | 98ca645f824301bde72e0a51cdc8bdbbea6774a5 (diff) | |
sched/rt: Remove unnecessary push for unfit tasks
In task_woken_rt() and switched_to_rto() we try trigger push-pull if the
task is unfit.
But the logic is found lacking because if the task was the only one
running on the CPU, then rt_rq is not in overloaded state and won't
trigger a push.
The necessity of this logic was under a debate as well, a summary of
the discussion can be found in the following thread:
https://lore.kernel.org/lkml/20200226160247.iqvdakiqbakk2llz@e107158-lin.cambridge.arm.com/
Remove the logic for now until a better approach is agreed upon.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fixes: 804d402fb6f6 ("sched/rt: Make RT capacity-aware")
Link: https://lkml.kernel.org/r/20200302132721.8353-6-qais.yousef@arm.com
| -rw-r--r-- | kernel/sched/rt.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index bcb143661a86..df11d88c9895 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2225,7 +2225,7 @@ static void task_woken_rt(struct rq *rq, struct task_struct *p) (rq->curr->nr_cpus_allowed < 2 || rq->curr->prio <= p->prio); - if (need_to_push || !rt_task_fits_capacity(p, cpu_of(rq))) + if (need_to_push) push_rt_tasks(rq); } @@ -2297,10 +2297,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p) */ if (task_on_rq_queued(p) && rq->curr != p) { #ifdef CONFIG_SMP - bool need_to_push = rq->rt.overloaded || - !rt_task_fits_capacity(p, cpu_of(rq)); - - if (p->nr_cpus_allowed > 1 && need_to_push) + if (p->nr_cpus_allowed > 1 && rq->rt.overloaded) rt_queue_push_tasks(rq); #endif /* CONFIG_SMP */ if (p->prio < rq->curr->prio && cpu_online(cpu_of(rq))) |