Re: [PATCH v5 1/2] sched, cgroup: Restore meaning to hierarchical_quota

[Phil Auld]

On Mon, Jul 10, 2023 at 10:17:08AM -1000 Tejun Heo wrote:
> Hello,
> 
> On Fri, Jul 07, 2023 at 03:57:47PM -0400, Phil Auld wrote:
> > @@ -11038,11 +11038,14 @@ static int tg_cfs_schedulable_down(struct task_group *tg, void *data)
> >  
> >  		/*
> >  		 * Ensure max(child_quota) <= parent_quota.  On cgroup2,
> > -		 * always take the min.  On cgroup1, only inherit when no
> > -		 * limit is set:
> > +		 * always take the non-RUNTIME_INF min.  On cgroup1, only
> > +		 * inherit when no limit is set:
> >  		 */
> >  		if (cgroup_subsys_on_dfl(cpu_cgrp_subsys)) {
> > -			quota = min(quota, parent_quota);
> > +			if (quota == RUNTIME_INF)
> > +				quota = parent_quota;
> > +			else if (parent_quota != RUNTIME_INF)
> > +				quota = min(quota, parent_quota);
> 
> Can you please add a comment explaining how hierarchical_quota is used in
> cgroup2? It seems like you're using it to detect whether bw limit is
> enforced for a given cgroup, which is fine, but the above code in isolation
> looks a bit curious because it doesn't serve any purpose by itself.

Sure, I can do that.



Cheers,
Phil

> 
> Thanks.
> 
> -- 
> tejun
> 

--