Messages in this thread | | | Date | Tue, 29 Jan 2013 16:42:14 +0800 | From | Libo Chen <> | Subject | Re: [PATCH]sched/rt: Do not try to push tasks if pinned task switches to RT |
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From: Libo Chen <libo.chen@huawei.com>
On 2013-1-29 4:23, Kirill Tkhai wrote: > Just switched pinned task is not able to be pushed. If the rq had had > several RT tasks before they have already been considered as candidates > to be pushed (or pulled). > > Signed-off-by: Kirill V Tkhai <tkhai@yandex.ru> > CC: Steven Rostedt <rostedt@goodmis.org> > CC: Ingo Molnar <mingo@kernel.org> > CC: Peter Zijlstra <peterz@infradead.org> > CC: linux-rt-users <linux-rt-users@vger.kernel.org> > --- > kernel/sched/rt.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c > index 4e8f0f4..5f7d92b 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -1925,9 +1925,9 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p) > */ > if (p->on_rq && rq->curr != p) { > #ifdef CONFIG_SMP > - if (rq->rt.overloaded && push_rt_task(rq) && > + if (rq->rt.overloaded && p->nr_cpus_allowed > 1 && > /* Don't resched if we changed runqueues */ > - rq != task_rq(p)) > + push_rt_task(rq) && rq != task_rq(p))
I think you worry about it was excess to call push_rt_task, since the task of p->nr_cpus_allowed=1 can`t be pushed. is that right?
The task of p->nr_cpus_allowed =1 would`t be added to pushable_tasks list (see the enqueue_task_rt())and this push_rt_task() need to push other tasks when rt.overloaded.
So I don`t agree this patch.
> check_resched = 0; > #endif /* CONFIG_SMP */ > if (check_resched && p->prio < rq->curr->prio) > -- > To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
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