From: sashiko-bot@kernel.org
To: "SJ Park" <sj@kernel.org>
Cc: damon@lists.linux.dev
Subject: Re: [RFC PATCH 3/3] mm/damon/core: move static variable rotation to damon_ctx
Date: Sat, 24 Oct 2026 19:37:58 +0000 [thread overview]
Message-ID: <sashiko-outbox-183857@kernel.org> (raw)
In-Reply-To: <20261024193351.87130-4-sj@kernel.org>
> damon_split_some_reigons() uses a static variable, rotation, to remember
> how many times it was called. It is again used to determine fair
> selection of regions to split. Since it is a static variable, it can be
> indeterministic and therefore less fair.
>
> The user impact is not critical. No crash, no leak. DAMON's
> best-effort and indeterministic monitoring accuracy could be slightly
> more indeterministic when multiple kdamonds are used in parallel.
>
> Fix the problem by moving the static variable into the damon_ctx struct.
>
> Fixes: 1a582e6e0174 ("mm/damon/core: split a fraction of regions when nr_regions exceeds max/2")
> Cc: <stable@vger.kernel.org> # 7.3.x
> Closes: https://sashiko.dev/#/bug/linux-eebfcdde-2881-48ef-8df1-e2019d2a47f2
> Signed-off-by: SJ Park <sj@kernel.org>
Sashiko has reviewed this patch and found no issues.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261024193351.87130-1-sj@kernel.org?part=3
prev parent reply other threads:[~2026-10-24 19:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-24 19:33 [RFC PATCH 0/3] mm/damon: fix three race bugs in sysfs and core SJ Park
2026-10-24 19:33 ` [RFC PATCH 1/3] mm/damon/sysfs-schemes: hold damon_sysfs_lock in target_metric_store() SJ Park
2026-10-24 19:44 ` sashiko-bot
2026-10-24 19:33 ` [RFC PATCH 2/3] mm/damon/core: move static variable last_nr_regions to damon_ctx SJ Park
2026-10-24 19:39 ` sashiko-bot
2026-10-24 19:33 ` [RFC PATCH 3/3] mm/damon/core: move static variable rotation " SJ Park
2026-10-24 19:37 ` sashiko-bot [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=sashiko-outbox-183857@kernel.org \
--to=sashiko-bot@kernel.org \
--cc=damon@lists.linux.dev \
--cc=sashiko-reviews@lists.linux.dev \
--cc=sj@kernel.org \
/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