Re: [PATCH 1/6] sched/ext: Fix scx vs sched_delayed

From: Christian Loehle
Date: Wed Oct 30 2024 - 11:50:19 EST


On 10/30/24 15:12, Peter Zijlstra wrote:
> Commit 98442f0ccd82 ("sched: Fix delayed_dequeue vs
> switched_from_fair()") forgot about scx :/
>
> Fixes: 98442f0ccd82 ("sched: Fix delayed_dequeue vs switched_from_fair()")
> Reported-by: Tejun Heo <tj@xxxxxxxxxx>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Link: https://lkml.kernel.org/r/20241030104934.GK14555@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> ---
> kernel/sched/ext.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> --- a/kernel/sched/ext.c
> +++ b/kernel/sched/ext.c
> @@ -4489,11 +4489,16 @@ static void scx_ops_disable_workfn(struc
> scx_task_iter_start(&sti);
> while ((p = scx_task_iter_next_locked(&sti))) {
> const struct sched_class *old_class = p->sched_class;
> + const struct sched_class *new_class =
> + __setscheduler_class(p->policy, p->prio);
> struct sched_enq_and_set_ctx ctx;
>
> + if (old_class != new_class && p->se.sched_delayed)
> + dequeue_task(task_rq(p), p, DEQUEUE_SLEEP | DEQUEUE_DELAYED);
> +
> sched_deq_and_put_task(p, DEQUEUE_SAVE | DEQUEUE_MOVE, &ctx);
>
> - p->sched_class = __setscheduler_class(p->policy, p->prio);
> + p->sched_class = new_class;
> check_class_changing(task_rq(p), p, old_class);
>
> sched_enq_and_set_task(&ctx);
> @@ -5199,12 +5204,17 @@ static int scx_ops_enable(struct sched_e
> scx_task_iter_start(&sti);
> while ((p = scx_task_iter_next_locked(&sti))) {
> const struct sched_class *old_class = p->sched_class;
> + const struct sched_class *new_class =
> + __setscheduler_class(p->policy, p->prio);
> struct sched_enq_and_set_ctx ctx;
>
> + if (old_class != new_class && p->se.sched_delayed)
> + dequeue_task(task_rq(p), p, DEQUEUE_SLEEP | DEQUEE_DELAYED);
> +

s/DEQUEE_DELAYED/DEQUEUE_DELAYED
Anyway, no luck for me applying the series onto sched/core scx's for-next or rc5.
Any hint or do you mind supplying a branch?