From: Francesco Nigro <nigro.fra@gmail.com>
To: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Valentin Schneider <vschneid@redhat.com>,
Mike Galbraith <efault@gmx.de>,
Mario Limonciello <mario.limonciello@amd.com>,
Huang Rui <ray.huang@amd.com>,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Subject: Re: [REPORT] sched: ITMT + DELAY_DEQUEUE: woken task waits ~1 ms behind another task on the preferred CPU while allowed CPUs are idle
Date: Wed, 11 Nov 2026 17:03:33 +0100 [thread overview]
Message-ID: <20261111160333.2206028-1-nigro.fra@gmail.com> (raw)
In-Reply-To: <99366157-08b9-411f-b180-fa61bc5f5002@amd.com>
On Thu, 2026-11-05 at 14:04 +0530, K Prateek Nayak wrote:
> I'm having a hard time understanding why asym_active_balance() would
> trigger before worker 482 blocks
Sorry, that is my trimming: the "blocks" row is 482's context switch.
The raw events (perf script on the same recording):
.654331 [6] 482 sched_stat_runtime runtime=792910 [ns]
.654334 [6] 482 sched_waking comm=migration/7
.654337 [6] 482 sched_switch 482 S ==> swapper/6
.654338 [7] 481 sched_switch 481 R ==> migration/7
.654341 [7] migration/7 sched_migrate_task 481 orig_cpu=7 dest_cpu=6
.654345 [6] swapper/6 sched_switch swapper/6 R ==> 481
Thanks,
Franz
prev parent reply other threads:[~2026-11-11 16:03 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-03 15:46 Francesco Nigro
2026-11-03 17:27 ` Mike Galbraith
2026-11-03 23:33 ` Francesco Nigro
2026-11-04 3:13 ` Mike Galbraith
2026-11-04 22:06 ` Francesco Nigro
2026-11-05 4:11 ` K Prateek Nayak
2026-11-05 8:12 ` Francesco Nigro
2026-11-05 8:34 ` K Prateek Nayak
2026-11-11 16:03 ` Francesco Nigro [this message]
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=20261111160333.2206028-1-nigro.fra@gmail.com \
--to=nigro.fra@gmail.com \
--cc=dietmar.eggemann@arm.com \
--cc=efault@gmx.de \
--cc=kprateek.nayak@amd.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mario.limonciello@amd.com \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=ray.huang@amd.com \
--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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®