From: Tejun Heo <tj@kernel.org>
To: Tao Cui <cui.tao@linux.dev>
Cc: Tao Cui <cuitao@kylinos.cn>,
void@manifault.com, arighi@nvidia.com, changwoo@igalia.com,
suzhidao@xiaomi.com, yphbchou0911@gmail.com,
zhaomengmeng@kylinos.cn, sched-ext@lists.linux.dev,
linux-kernel@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH] sched_ext/scx_flatcg: expire cached hweights on weight changes
Date: Fri, 14 Aug 2026 10:56:19 -1000 [thread overview]
Message-ID: <003d0a4f1c448113e18f9f5d61d00e99@kernel.org> (raw)
In-Reply-To: <20260814144116.2767304-1-cui.tao@linux.dev>
On Fri, Aug 14, 2026 at 10:41:16PM +0800, Tao Cui wrote:
> fcg_cgroup_set_weight() updates cgc->weight and the parent's
> child_weight_sum but doesn't bump hweight_gen, so the hweights cached by
> cgrp_refresh_hweight() stay stale until some task activation bumps the
> generation. For cgroups whose tasks never go through a 0->n runnable
> transition (e.g. persistently busy ones), a cpu.weight change never
> propagates to scheduling at all.
Applied to sched_ext/for-7.3.
Thanks.
--
tejun
prev parent reply other threads:[~2026-08-14 20:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-14 14:41 [PATCH] sched_ext/scx_flatcg: expire cached hweights on weight changes Tao Cui
2026-08-14 14:48 ` Tao Cui
2026-08-14 22:23 ` Tejun Heo
2026-08-14 17:20 ` bot+bpf-ci
2026-08-14 20:56 ` Tejun Heo [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=003d0a4f1c448113e18f9f5d61d00e99@kernel.org \
--to=tj@kernel.org \
--cc=arighi@nvidia.com \
--cc=bpf@vger.kernel.org \
--cc=changwoo@igalia.com \
--cc=cui.tao@linux.dev \
--cc=cuitao@kylinos.cn \
--cc=linux-kernel@vger.kernel.org \
--cc=sched-ext@lists.linux.dev \
--cc=suzhidao@xiaomi.com \
--cc=void@manifault.com \
--cc=yphbchou0911@gmail.com \
--cc=zhaomengmeng@kylinos.cn \
/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