From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Song Hu <husong@kylinos.cn>,
akpm@linux-foundation.org, usama.anjum@arm.com
Cc: linux-mm@kvack.org, shuah@kernel.org, ljs@kernel.org,
liam@infradead.org, vbabka@kernel.org, rppt@kernel.org,
surenb@google.com, mhocko@suse.com, peterx@redhat.com,
sarthak.sharma@arm.com, linux-kselftest@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 3/3] selftests/mm: restore enable_soft_offline in hugetlb-soft-offline
Date: Thu, 10 Sep 2026 11:36:13 +0200 [thread overview]
Message-ID: <54242581-c5e4-433e-8fd8-e83da1383f42@kernel.org> (raw)
In-Reply-To: <20260825085756.63030-4-husong@kylinos.cn>
On 8/25/26 10:57, Song Hu wrote:
> hugetlb-soft-offline toggles /proc/sys/vm/enable_soft_offline between 1
> and 0 (test_soft_offline_common(1) then (0)) and leaves it at 0 when it
> finishes, silently disabling soft offlining for the whole system after
> the run.
>
> Save the original value before the test and restore it from an
> atexit() handler, as hugepage_restore_settings_atexit() in
> hugepage_settings.c already does. Use read_num()/write_num() from
> vm_util instead of hand-rolled popen()/fopen() helpers.
>
> The restore handler must not call write_num(): on failure it
> re-enters exit() through ksft_exit_fail_msg(), which is undefined
> behavior from inside an atexit handler. A non-root run hits it
> directly - the restore write fails the same way the write that
> triggered the exit did. Restore with plain open()/write(), best
> effort.
>
> Signed-off-by: Song Hu <husong@kylinos.cn>
>
> ---
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
--
Cheers,
David
prev parent reply other threads:[~2026-09-10 9:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-25 8:57 [PATCH v4 0/3] selftests/mm: TAP output and global-state fixes Song Hu
2026-08-25 8:57 ` [PATCH v4 1/3] selftests/mm: emit TAP header in uffd-wp-mremap Song Hu
2026-09-10 9:28 ` David Hildenbrand (Arm)
2026-08-25 8:57 ` [PATCH v4 2/3] selftests/mm: emit TAP header and use TAP skip in mremap_test Song Hu
2026-09-10 9:33 ` David Hildenbrand (Arm)
2026-08-25 8:57 ` [PATCH v4 3/3] selftests/mm: restore enable_soft_offline in hugetlb-soft-offline Song Hu
2026-08-25 9:06 ` Song Hu
2026-08-25 9:24 ` Muhammad Usama Anjum
2026-09-10 9:36 ` David Hildenbrand (Arm) [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=54242581-c5e4-433e-8fd8-e83da1383f42@kernel.org \
--to=david@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=husong@kylinos.cn \
--cc=liam@infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=ljs@kernel.org \
--cc=mhocko@suse.com \
--cc=peterx@redhat.com \
--cc=rppt@kernel.org \
--cc=sarthak.sharma@arm.com \
--cc=shuah@kernel.org \
--cc=surenb@google.com \
--cc=usama.anjum@arm.com \
--cc=vbabka@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 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.