Re: [PATCH] sched_ext: Fix missing rq lock in scx_bpf_cpuperf_set()

From: Tejun Heo
Date: Thu Mar 27 2025 - 13:19:44 EST


Hello,

On Thu, Mar 27, 2025 at 06:15:09PM +0100, Andrea Righi wrote:
> > If we don't want to do locked rq tracking, we can always use
> > schedule_deferred() when any rq is locked too. That's a bit more expensive
> > tho.
>
> Yeah, I'm a bit worried that locked rq tracking might introduce overhead to
> all the scx callbacks, just to address this issue.

All operaitons are already wrapped with SCX_CALL_OP() and updating per-cpu
state (kf flags). It's unlikely that another percpu variable update is going
to be noticeable.

Thanks.

--
tejun