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 A8FDC255E43 for ; Sun, 29 Mar 2026 00:41:55 +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=1774744915; cv=none; b=YpfKVBbL+58dSsP3Authn7TNQrAFNINRTnnsR1dWVmyy15//jSATAGv5O5de0Wu2MdUwRGNysokLBCAHJP0t89CwAexy4BSyDZX3Knx0uO2TgG5iNVxM2Fs/icbWdwYke4cfh7KzU/OmlEz2HMUm7nae1aiXoRvyD7VHzLDJYnc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774744915; c=relaxed/simple; bh=hLEXj43wYh77gsCp7fFrbPRJ6meedkMYRFzt32B+unU=; h=Date:To:From:Subject:Message-Id; b=Y3RxdPTjMIhqM7HfTzDEcWP9XRaReZ2kH/6I8Fs+ESYR9GDspl+1GvklwPP8vs/5A1cDG5yqpn5r/30VQg/2hgFD/691YM9KI8fOFp2Hh8orKBtDgR6X4T/QOE5goST8FGnMxMrY/9tG7WGEx/sd1mCaxWr7XfrJyFjN98svM9M= 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=YPnCUtjK; 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="YPnCUtjK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A992C4CEF7; Sun, 29 Mar 2026 00:41:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774744915; bh=hLEXj43wYh77gsCp7fFrbPRJ6meedkMYRFzt32B+unU=; h=Date:To:From:Subject:From; b=YPnCUtjKx5HWgDUJwRtevaSloz/L4joxxQl5bPtwNQMoekQx2vzLz76p/XPvwZRDo cDvRjS/+QvV0rNRdWxasIV2po0EMoTQhe78PVK5R2afDto5lBLvBM98qPI6APtS1tp V2+ZN/b0qf41d5n1dIPVU8KA5hgp1yMK/fna8YB4= Date: Sat, 28 Mar 2026 17:41:55 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,surenb@google.com,skhan@linuxfoundation.org,sj@kernel.org,rppt@kernel.org,mhocko@suse.com,ljs@kernel.org,liam.howlett@oracle.com,david@kernel.org,corbet@lwn.net,aethernet65535@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] docs-mm-damon-document-exclusivity-of-special-purpose-modules.patch removed from -mm tree Message-Id: <20260329004155.7A992C4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: Docs/mm/damon: document exclusivity of special-purpose modules has been removed from the -mm tree. Its filename was docs-mm-damon-document-exclusivity-of-special-purpose-modules.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: Liew Rui Yan Subject: Docs/mm/damon: document exclusivity of special-purpose modules Date: Sun, 15 Mar 2026 09:29:44 -0700 Add a section in design.rst to explain that DAMON special-purpose kernel modules (LRU_SORT, RECLAIM, STAT) run in an exclusive manner and return -EBUSY if another is already running. Update lru_sort.rst, reclaim.rst and stat.rst by adding cross-references to this exclusivity rule at the end of their respective Example sections. This change is motivated from another discussion [1]. Link: https://lkml.kernel.org/r/20260315162945.80994-1-sj@kernel.org Link: https://lore.kernel.org/damon/20260314002119.79742-1-sj@kernel.org/T/#t [1] Signed-off-by: Liew Rui Yan Reviewed-by: SeongJae Park Signed-off-by: SeongJae Park Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Liam Howlett Cc: Lorenzo Stoakes (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- Documentation/admin-guide/mm/damon/lru_sort.rst | 5 +++++ Documentation/admin-guide/mm/damon/reclaim.rst | 5 +++++ Documentation/admin-guide/mm/damon/stat.rst | 5 +++++ Documentation/mm/damon/design.rst | 4 ++++ 4 files changed, 19 insertions(+) --- a/Documentation/admin-guide/mm/damon/lru_sort.rst~docs-mm-damon-document-exclusivity-of-special-purpose-modules +++ a/Documentation/admin-guide/mm/damon/lru_sort.rst @@ -351,3 +351,8 @@ the LRU-list based page granularity recl # echo 400 > wmarks_mid # echo 200 > wmarks_low # echo Y > enabled + +Note that this module (damon_lru_sort) cannot run simultaneously with other +DAMON-based special-purpose modules. Refer to :ref:`DAMON design special +purpose modules exclusivity ` +for more details. --- a/Documentation/admin-guide/mm/damon/reclaim.rst~docs-mm-damon-document-exclusivity-of-special-purpose-modules +++ a/Documentation/admin-guide/mm/damon/reclaim.rst @@ -318,6 +318,11 @@ granularity reclamation. :: # echo 200 > wmarks_low # echo Y > enabled +Note that this module (damon_reclaim) cannot run simultaneously with other +DAMON-based special-purpose modules. Refer to :ref:`DAMON design special +purpose modules exclusivity ` +for more details. + .. [1] https://research.google/pubs/pub48551/ .. [2] https://lwn.net/Articles/787611/ .. [3] https://www.kernel.org/doc/html/latest/mm/free_page_reporting.html --- a/Documentation/admin-guide/mm/damon/stat.rst~docs-mm-damon-document-exclusivity-of-special-purpose-modules +++ a/Documentation/admin-guide/mm/damon/stat.rst @@ -45,6 +45,11 @@ You can enable DAMON_STAT by setting the Setting it as ``N`` disables DAMON_STAT. The default value is set by ``CONFIG_DAMON_STAT_ENABLED_DEFAULT`` build config option. +Note that this module (damon_stat) cannot run simultaneously with other +DAMON-based special-purpose modules. Refer to :ref:`DAMON design special +purpose modules exclusivity ` +for more details. + .. _damon_stat_aggr_interval_us: aggr_interval_us --- a/Documentation/mm/damon/design.rst~docs-mm-damon-document-exclusivity-of-special-purpose-modules +++ a/Documentation/mm/damon/design.rst @@ -853,6 +853,10 @@ more detail, please read the usage docum (:doc:`/admin-guide/mm/damon/stat`, :doc:`/admin-guide/mm/damon/reclaim` and :doc:`/admin-guide/mm/damon/lru_sort`). +.. _damon_design_special_purpose_modules_exclusivity: + +Note that these modules currently run in an exclusive manner. If one of those +is already running, others will return ``-EBUSY`` upon start requests. Sample DAMON Modules -------------------- _ Patches currently in -mm which might be from aethernet65535@gmail.com are