From: Libo Chen <[email protected]>
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 <[email protected]> > CC: Steven Rostedt <[email protected]> > CC: Ingo Molnar <[email protected]> > CC: Peter Zijlstra <[email protected]> > CC: linux-rt-users <[email protected]> > --- > 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 [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
