From: Aaron Lu <ziqianlu@bytedance.com>
To: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: "Valentin Schneider" <vschneid@redhat.com>,
"Ben Segall" <bsegall@google.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Chengming Zhou" <chengming.zhou@linux.dev>,
"Josh Don" <joshdon@google.com>, "Ingo Molnar" <mingo@redhat.com>,
"Vincent Guittot" <vincent.guittot@linaro.org>,
"Xi Wang" <xii@google.com>,
linux-kernel@vger.kernel.org,
"Juri Lelli" <juri.lelli@redhat.com>,
"Dietmar Eggemann" <dietmar.eggemann@arm.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Mel Gorman" <mgorman@suse.de>,
"Chuyi Zhou" <zhouchuyi@bytedance.com>,
"Jan Kiszka" <jan.kiszka@siemens.com>,
"Florian Bezdeka" <florian.bezdeka@siemens.com>,
"Songtang Liu" <liusongtang@bytedance.com>,
"Chen Yu" <yu.c.chen@intel.com>,
"Matteo Martelli" <matteo.martelli@codethink.co.uk>,
"Michal Koutný" <mkoutny@suse.com>,
"Sebastian Andrzej Siewior" <bigeasy@linutronix.de>
Subject: Re: [PATCH] sched/fair: Prevent cfs_rq from being unthrottled with zero runtime_remaining
Date: Wed, 1 Oct 2025 19:58:42 +0800 [thread overview]
Message-ID: <20251001115842.GA674@bytedance> (raw)
In-Reply-To: <dc328049-b1e6-4558-bb9b-e2e1d186daeb@amd.com>
On Tue, Sep 30, 2025 at 07:08:20PM +0530, K Prateek Nayak wrote:
> Hello Aaron,
>
> I'll merge the two replies in one.
>
> On 9/30/2025 4:37 PM, Aaron Lu wrote:
> > So in my original patch, cfs_rqs will (most likely) start with
> > runtime_remaining == 1 and unthrottled after calling throttle_cfs_rq(),
> > which will also start the B/W timer. The timer is not needed in this
> > case when no cfs_rqs are actually throttled but it doesn't hurt. Looks
> > like everything is OK, we do not need to do any special handling in
> > enqueue_throttled_task(). Thoughts?
>
> Now that I look at throttle_cfs_rq() properly, we'll only move the
> runtime_remaining from 0 to 1 so few usecs worth of bandwidth
> distributed at max should be okay. Sorry for the being overly cautious!
Never mind.
>
> So your current approach should be good. Please feel free to include:
>
> Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Thanks!
next prev parent reply other threads:[~2025-10-01 11:58 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-29 7:46 [PATCH] sched/fair: Prevent cfs_rq from being unthrottled with zero runtime_remaining Aaron Lu
2025-09-29 9:34 ` K Prateek Nayak
2025-09-29 10:55 ` Aaron Lu
2025-09-30 7:56 ` Aaron Lu
2025-09-30 8:58 ` K Prateek Nayak
2025-09-30 9:27 ` Aaron Lu
2025-09-30 11:07 ` Aaron Lu
2025-09-30 12:39 ` Aaron Lu
2025-09-30 13:38 ` K Prateek Nayak
2025-10-01 11:58 ` Aaron Lu [this message]
2025-10-14 7:43 ` Hao Jia
2025-10-14 9:11 ` Aaron Lu
2025-10-14 11:01 ` Hao Jia
2025-10-14 11:50 ` Aaron Lu
2025-10-15 1:43 ` Hao Jia
2025-10-15 1:48 ` Hao Jia
2025-10-15 2:51 ` Aaron Lu
2025-10-15 6:31 ` Hao Jia
2025-10-15 8:40 ` Aaron Lu
2025-10-15 10:21 ` Hao Jia
2025-10-16 6:54 ` Aaron Lu
2025-10-16 7:49 ` Hao Jia
2025-10-16 9:23 ` Aaron Lu
2025-10-16 11:04 ` Hao Jia
2025-10-16 11:46 ` Aaron Lu
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