From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5086E36E476; Sat, 18 Apr 2026 07:55:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776498909; cv=none; b=WJN0/EdBQRPcTcdT3krGYhPtXLHGkAdgrzA0hUmSd+j3JBnAIIga5ctem4Ng5hQXNk1RAMP76k7WXWvAPrt/cKuampd1fnl1AA5um37MG+56qOVQtcSDt1Bf/v1STgaVdtB/4p9bQD5CrcD4EcB5rv5qcrh3pgkb6/5gxHecfgI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776498909; c=relaxed/simple; bh=zy2exY+W79EhQ4eULeVVNfiA6QqczW5YXeXX6v0K1xM=; h=Date:To:From:Subject:Message-Id; b=ixyrSIVVs7PEqxqLhcJ76HORPog5o2OCfPx2xFuhfY2Xhlnqx0vFVibEZHHcr0PKGU35Zcc2XGi+45LsBZa8oXV5BrMI9N4YHwL9xJIsDguB/4yxlutaMJvWxp2XVPe9ucENN8epNFeojsx3yWKaTq0p+OOIKsJ67z+pEiBFPvA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=ElEYOR3D; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ElEYOR3D" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 477C8C19424; Sat, 18 Apr 2026 07:55:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1776498909; bh=zy2exY+W79EhQ4eULeVVNfiA6QqczW5YXeXX6v0K1xM=; h=Date:To:From:Subject:From; b=ElEYOR3DJyCVIlW2bMUKliiayqdXEFYWoY0n/4DA/mQHzxFFFazD2M84qXsRqFn5y 10oIuGu4qfoKqRTgLPiHT0+RGD3NcmmtNjRP0wOJ8dlee74Y1MMDFxNWBkcFy6HbsB CynV5Vsemuoc59xki/JHKDecVyNghu5QcIPz5EG8= Date: Sat, 18 Apr 2026 00:55:04 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] docs-admin-guide-mm-damon-lru_sort-warn-commit_inputs-vs-param-updates-race.patch removed from -mm tree Message-Id: <20260418075508.477C8C19424@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: Docs/admin-guide/mm/damon/lru_sort: warn commit_inputs vs param updates race has been removed from the -mm tree. Its filename was docs-admin-guide-mm-damon-lru_sort-warn-commit_inputs-vs-param-updates-race.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: SeongJae Park Subject: Docs/admin-guide/mm/damon/lru_sort: warn commit_inputs vs param updates race Date: Sun, 29 Mar 2026 08:30:50 -0700 DAMON_LRU_SORT handles commit_inputs request inside kdamond thread, reading the module parameters. If the user updates the module parameters while the kdamond thread is reading those, races can happen. To avoid this, the commit_inputs parameter shows whether it is still in the progress, assuming users wouldn't update parameters in the middle of the work. Some users might ignore that. Add a warning about the behavior. The issue was discovered in [1] by sashiko. Link: https://lore.kernel.org/20260329153052.46657-3-sj@kernel.org Link: https://lore.kernel.org/20260319161620.189392-2-objecting@objecting.org [1] Fixes: 6acfcd0d7524 ("Docs/admin-guide/damon: add a document for DAMON_LRU_SORT") Signed-off-by: SeongJae Park Cc: # 6.0.x Signed-off-by: Andrew Morton --- Documentation/admin-guide/mm/damon/lru_sort.rst | 4 ++++ 1 file changed, 4 insertions(+) --- a/Documentation/admin-guide/mm/damon/lru_sort.rst~docs-admin-guide-mm-damon-lru_sort-warn-commit_inputs-vs-param-updates-race +++ a/Documentation/admin-guide/mm/damon/lru_sort.rst @@ -79,6 +79,10 @@ of parametrs except ``enabled`` again. parameter is set as ``N``. If invalid parameters are found while the re-reading, DAMON_LRU_SORT will be disabled. +Once ``Y`` is written to this parameter, the user must not write to any +parameters until reading ``commit_inputs`` again returns ``N``. If users +violate this rule, the kernel may exhibit undefined behavior. + active_mem_bp ------------- _ Patches currently in -mm which might be from sj@kernel.org are mm-damon-core-disallow-time-quota-setting-zero-esz.patch mm-damon-core-disallow-non-power-of-two-min_region_sz-on-damon_start.patch