Re: [PATCH v2 1/6] sched/cache: Keep nr_pref_llc_running in the runnable domain

[Chen, Yu C]

Hi Peter,

On 9/22/2026 3:22 PM, Peter Zijlstra wrote:
> On Mon, Sep 21, 2026 at 05:37:22PM -0700, Tim Chen wrote:
> > @@ -6395,15 +6429,27 @@ static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);
> >   
> >   static void set_delayed(struct sched_entity *se)
> >   {
> > -	se->sched_delayed = 1;
> > -
> >   	/*
> >   	 * Delayed se of cfs_rq have no tasks queued on them.
> >   	 * Do not adjust h_nr_runnable since __dequeue_task()
> >   	 * will account it for blocked tasks.
> > +	 *
> > +	 * This check can be removed because when flat pick
> > +	 * patches get merged as only task can get delayed,
> > +	 * same for clear_delayed().
> >   	 */
> > -	if (!entity_is_task(se))
> > +	if (!entity_is_task(se)) {
> > +		se->sched_delayed = 1;
> >   		return;
> > +	}
>
> This is dead code. In Linus' tree, where this will be applied, this can
> never happen. A possible backport of this fix however will need to take
> care.

Would you prefer that we create a separate patch to remove entity_is_task()
for Linus's tree (so that the current patch can be backported, since 
cache-aware
scheduling was merged before flat task-pickup)?

thanks,
Chenyu