From: Phil Auld <pauld@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: linux-kernel@vger.kernel.org, Juri Lelli <juri.lelli@redhat.com>,
Ingo Molnar <mingo@redhat.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Valentin Schneider <vschneid@redhat.com>,
Ben Segall <bsegall@google.com>,
Steven Rostedt <rostedt@goodmis.org>,
Mel Gorman <mgorman@suse.de>,
Frederic Weisbecker <frederic@kernel.org>
Subject: Re: [PATCH v5 1/2] sched, cgroup: Restore meaning to hierarchical_quota
Date: Mon, 10 Jul 2023 17:04:21 -0400 [thread overview]
Message-ID: <20230710210421.GA146093@lorien.usersys.redhat.com> (raw)
In-Reply-To: <ZKxnRIZQzyVDMZGD@slm.duckdns.org>
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
>
--
next prev parent reply other threads:[~2023-07-10 21:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-07 19:57 [PATCH v5 0/2] Fix nohz_full vs cfs bandwidth Phil Auld
2023-07-07 19:57 ` [PATCH v5 1/2] sched, cgroup: Restore meaning to hierarchical_quota Phil Auld
2023-07-10 20:17 ` Tejun Heo
2023-07-10 21:04 ` Phil Auld [this message]
2023-07-11 0:00 ` Benjamin Segall
2023-07-11 13:13 ` Phil Auld
2023-07-07 19:57 ` [PATCH v5 2/2] Sched/fair: Block nohz tick_stop when cfs bandwidth in use Phil Auld
2023-07-10 23:54 ` Benjamin Segall
2023-07-11 13:10 ` Phil Auld
2023-07-11 14:12 ` Phil Auld
2023-07-11 22:07 ` Benjamin Segall
2023-07-11 22:22 ` Phil Auld
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