Re: [PATCH 1/3] sched/deadline: clear dl_entity params when setscheduling to different class

[Vincent Legout <vincent@legout.info>]

Hello,

Juri Lelli <juri.lelli@arm.com> writes:

> When a task is using SCHED_DEADLINE and the user setschedules it to a different
> class its sched_dl_entity static parameters are not cleaned up. This causes a
> bug if the user sets it back to SCHED_DEADLINE with the same parameters again.
> The problem resides in the check we perform at the very beginning of
> dl_overflow():
>
> 	if (new_bw == p->dl.dl_bw)
> 		return 0;
>
> This condition is met in the case depicted above, so the function returns and
> dl_b->total_bw is not updated (the p->dl.dl_bw is not added to it). After this,
> admission control is broken.
>
> This patch fixes the thing, properly clearing static parameters for a task
> that ceases to use SCHED_DEADLINE.

Thanks, this fixes the issue I had:

Tested-by: Vincent Legout <vincent@legout.info>

Thanks,
Vincent