From: Libo Chen <libo.chen@xxxxxxxxxx>
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@xxxxxxxxx>
> CC: Steven Rostedt <rostedt@xxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> CC: linux-rt-users <linux-rt-users@xxxxxxxxxxxxxxx>
> ---
> 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@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
