Re: [PATCH] sched/fair: Propagate load for throttled cfs_rq

[Aaron Lu]

On Tue, Sep 09, 2025 at 11:52:55AM +0530, K Prateek Nayak wrote:
> Hello Aaron,
> 
> On 9/9/2025 11:47 AM, Aaron Lu wrote:
> >>>> kernel/sched/fair.c:6747:1: error: expected identifier or '(' before '+' token
> >>     6747 | +static inline bool cfs_rq_pelt_clock_throttled(struct cfs_rq *cfs_rq)
> >>          | ^
> > 
> > Sigh, I remembered I did a build test with !CFS_BANDWIDTH and now I went
> > to check that build directory and noticed I didn't have CFS_BANDWIDTH
> > disabled...
> > 
> > Sorry for the trouble, will send an updated patch later.
> 
> While at it, another nit.
> 
> On 9/8/2025 4:35 PM, Aaron Lu wrote:
> > @@ -13151,10 +13161,13 @@ static void propagate_entity_cfs_rq(struct sched_entity *se)
> >  {
> >  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
> >  
> > -	if (cfs_rq_throttled(cfs_rq))
> > -		return;
> > -
> > -	if (!throttled_hierarchy(cfs_rq))
> > +	/*
> > +	 * If a task gets attached to this cfs_rq and before being queued,
> > +	 * it gets migrated to another CPU due to reasons like cpuset change,
> > +	 * we need to make sure this cfs_rq stays on leaf cfs_rq list to
> > +	 * have that removed load decayed or it can cause faireness problem.
> > +	 */
> > +	if(!cfs_rq_pelt_clock_throttled(cfs_rq))
> 
>           ^ Can you also add a space after the "if" here.
>

Yeah, I definitely should do that, thanks for catching this.

> >  		list_add_leaf_cfs_rq(cfs_rq);
>