From: Tejun Heo <tj@kernel.org>
To: Andrea Righi <arighi@nvidia.com>
Cc: David Vernet <void@manifault.com>,
Changwoo Min <changwoo@igalia.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched_ext: Refresh idle state when kicking CPUs
Date: Mon, 6 Jan 2025 08:53:20 -1000 [thread overview]
Message-ID: <Z3wmoFPes_Qb-hTg@slm.duckdns.org> (raw)
In-Reply-To: <Z3jd8ohf_05k1ie3@gpd3>
Hello,
On Sat, Jan 04, 2025 at 08:06:26AM +0100, Andrea Righi wrote:
...
> The issue is that we call ops.update_idle() when a CPU enters or exits
> SCHED_IDLE, whereas it should ideally be called when the CPU transitions
> in/out of the idle state. So perhaps a kick from idle should trigger
> ops.update_idle(cpu, false)? Still, I'm not sure if that would provide any
> benefit... after all, do you see any practical scenarios where having
> unbalanced transitions could be a problem?
If possible, we should keep the calls balanced even if that means a bit of
complications on the core side as these things can become subtle bugs from
BPF scheduler side. And, yeah, I think kicking transitioning the CPU out of
idle makes sense to me.
Thanks.
--
tejun
next prev parent reply other threads:[~2025-01-06 18:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-01 18:24 [PATCH] sched_ext: Refresh idle state when kicking CPUs Andrea Righi
2025-01-02 22:33 ` Tejun Heo
2025-01-03 8:55 ` Andrea Righi
2025-01-03 21:39 ` Tejun Heo
2025-01-04 7:06 ` Andrea Righi
2025-01-06 18:53 ` Tejun Heo [this message]
2025-01-08 0:17 ` kernel test robot
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=Z3wmoFPes_Qb-hTg@slm.duckdns.org \
--to=tj@kernel.org \
--cc=arighi@nvidia.com \
--cc=changwoo@igalia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=void@manifault.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