All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Aaron Lu" <ziqianlu@bytedance.com>
To: "K Prateek Nayak" <kprateek.nayak@amd.com>
Cc: "Ingo Molnar" <mingo@redhat.com>,
	 "Peter Zijlstra" <peterz@infradead.org>,
	 "Juri Lelli" <juri.lelli@redhat.com>,
	 "Vincent Guittot" <vincent.guittot@linaro.org>,
	 "Dietmar Eggemann" <dietmar.eggemann@arm.com>,
	 "Steven Rostedt" <rostedt@goodmis.org>,
	 "Ben Segall" <bsegall@google.com>,
	"Mel Gorman" <mgorman@suse.de>,
	 "Valentin Schneider" <vschneid@redhat.com>,
	 "Josh Don" <joshdon@google.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/5] sched/fair: Call update_curr() before unthrottling the hierarchy
Date: Mon, 1 Jun 2026 11:52:01 +0800	[thread overview]
Message-ID: <20260601035201.GA690044@bytedance.com> (raw)
In-Reply-To: <20260528094830.13291-4-kprateek.nayak@amd.com>

Hi Prateek,

On Thu, May 28, 2026 at 09:48:28AM +0000, K Prateek Nayak wrote:
> Subsequent commits will allow update_curr() to throttle the hierarchy
> when the runtime accounting exceeds allocated quota. Call update_curr()
> before the unthrottle event, and in tg_unthrottle_up() to catch up on
> any remaining runtime and stabilize the "runtime_remaining" and
> "throttle_count" for that cfs_rq.
> 
> Doing an update_curr() early ensures the cfs_rq is not throttled right
> back up again when the unthrottle is in progress.
> 
> Since all callers of unthrottle_cfs_rq(), except one, already update the
> rq_clock and call rq_clock_start_loop_update(), move the
> update_rq_clock() in unthrottle_cfs_rq() to the lonely caller that
> doesn't update the rq_clock.

Looks like there is one more path that doesn't have clock updated:
cpu_max_write() -> tg_set_bandwidth() -> tg_set_cfs_bandwidth() ->
unthrottle_cfs_rq().

  parent reply	other threads:[~2026-06-01  3:52 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-28  9:48 [PATCH 0/5] sched/fair: Allow account_cfs_rq_runtime() to throttle current hierarchy K Prateek Nayak
2026-05-28  9:48 ` [PATCH 1/5] sched/fair: Convert cfs bandwidth throttling to use guards K Prateek Nayak
2026-05-28 21:46   ` Benjamin Segall
2026-05-28  9:48 ` [PATCH 2/5] sched/fair: Use throttled_csd_list for local unthrottle K Prateek Nayak
2026-05-28 21:53   ` Benjamin Segall
2026-05-28  9:48 ` [PATCH 3/5] sched/fair: Call update_curr() before unthrottling the hierarchy K Prateek Nayak
2026-05-28 22:03   ` Benjamin Segall
2026-06-01  3:52   ` Aaron Lu [this message]
2026-06-01  5:50     ` K Prateek Nayak
2026-06-01 11:27       ` Peter Zijlstra
2026-06-02  6:33         ` K Prateek Nayak
2026-05-28  9:48 ` [PATCH 4/5] sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up() K Prateek Nayak
2026-05-28 22:14   ` Benjamin Segall
2026-05-28  9:48 ` [PATCH 5/5] sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime() K Prateek Nayak
2026-05-28 22:44   ` Benjamin Segall
2026-06-01 13:48   ` Peter Zijlstra
2026-06-02  7:01     ` K Prateek Nayak
2026-06-02  8:32       ` Peter Zijlstra
2026-06-02  8:57         ` K Prateek Nayak
2026-05-28 11:45 ` [PATCH 0/5] sched/fair: Allow account_cfs_rq_runtime() to throttle current hierarchy Peter Zijlstra
2026-06-01  6:18 ` Aaron Lu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260601035201.GA690044@bytedance.com \
    --to=ziqianlu@bytedance.com \
    --cc=bsegall@google.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=joshdon@google.com \
    --cc=juri.lelli@redhat.com \
    --cc=kprateek.nayak@amd.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=vincent.guittot@linaro.org \
    --cc=vschneid@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.