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 697692BE056 for ; Sun, 8 Mar 2026 20:36:06 +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=1773002166; cv=none; b=dYfqKzZAxgcnkTa+9a4CCyIbW0gD7kstMe4RlI5UA6WYH6RuUG9xribPzU665FYbFH6P+GDj83po5EV3h+dQsldYfi9YB7R+dKmK8X+zbbiCrWVXMJHN4lzZm0OsylJjiJzcOlZDoRsHM/iqeqUkVpts/FpPN6e6oY0mW4HgQvE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773002166; c=relaxed/simple; bh=G9/PHt99O3uhxv+QTEq9++fKGSQb26BD4AhwVOiLOdw=; h=Date:To:From:Subject:Message-Id; b=ovJNpA3EUMkL35bD/l85oni6XJqSf6KarkYF9zSCq5AaBUY7ZucJSdofStp3Vb3d9vf3BoE9zNzWwyLD4iczXwb2oauiyHbVfhb3eFIlISw9y3gpdbWHyTG2IohMaoe+q0v5dW/k0JTH5/V9mPMN/KQaXFduYINE07Bw/9VchZ4= 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=k7gGfRzU; 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="k7gGfRzU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D618CC2BCAF; Sun, 8 Mar 2026 20:36:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1773002165; bh=G9/PHt99O3uhxv+QTEq9++fKGSQb26BD4AhwVOiLOdw=; h=Date:To:From:Subject:From; b=k7gGfRzUCRCm0PxeFo1yawaWJbaedzxECCSi4bNA3UNZ1BB0wPj8VDvuJjZY8krqh iwmOQRXW55A+OCUxbiGkkym9WfRoCPyx+DdDxTdIZT+iJzSB/t5qucbg7uaaoz5ZQY ea1XCHi3Fx02ciKpBG9yZMILswBrN5Qkgs7oZzzk= Date: Sun, 08 Mar 2026 13:36:05 -0700 To: mm-commits@vger.kernel.org,surenb@google.com,rppt@kernel.org,mhocko@suse.com,ljs@kernel.org,liam.howlett@oracle.com,david@kernel.org,davidgow@google.com,corbet@lwn.net,brendan.higgins@linux.dev,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + docs-mm-damon-design-document-the-power-of-two-limitation-for-addr_unit.patch added to mm-new branch Message-Id: <20260308203605.D618CC2BCAF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: Docs/mm/damon/design: document the power-of-two limitation for addr_unit has been added to the -mm mm-new branch. Its filename is docs-mm-damon-design-document-the-power-of-two-limitation-for-addr_unit.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/docs-mm-damon-design-document-the-power-of-two-limitation-for-addr_unit.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: SeongJae Park Subject: Docs/mm/damon/design: document the power-of-two limitation for addr_unit Date: Sat, 7 Mar 2026 11:42:21 -0800 The min_region_sz is set as max(DAMON_MIN_REGION_SZ / addr_unit, 1). DAMON_MIN_REGION_SZ is the same to PAGE_SIZE, and addr_unit is what the user can arbitrarily set. Commit c80f46ac228b ("mm/damon/core: disallow non-power of two min_region_sz") made min_region_sz to always be a power of two. Hence, addr_unit should be a power of two when it is smaller than PAGE_SIZE. While 'addr_unit' is a user-exposed parameter, the rule is not documented. This can confuse users. Specifically, if the user sets addr_unit as a value that is smaller than PAGE_SIZE and not a power of two, the setup will explicitly fail. Document the rule on the design document. Usage documents reference the design document for detail, so updating only the design document should suffice. Link: https://lkml.kernel.org/r/20260307194222.202075-3-sj@kernel.org Signed-off-by: SeongJae Park Cc: Brendan Higgins Cc: David Gow Cc: David Hildenbrand Cc: Jonathan Corbet Cc: Liam Howlett Cc: Lorenzo Stoakes (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- Documentation/mm/damon/design.rst | 2 ++ 1 file changed, 2 insertions(+) --- a/Documentation/mm/damon/design.rst~docs-mm-damon-design-document-the-power-of-two-limitation-for-addr_unit +++ a/Documentation/mm/damon/design.rst @@ -150,6 +150,8 @@ address on the given address space. Sup up to each operations set implementation. ``paddr`` is the only operations set implementation that supports the parameter. +If the value is smaller than ``PAGE_SIZE``, only a power of two should be used. + .. _damon_core_logic: Core Logics _ Patches currently in -mm which might be from sj@kernel.org are mm-damon-core-set-quota-score-histogram-with-core-filters.patch mm-damon-core-do-non-safe-region-walk-on-kdamond_apply_schemes.patch mm-damon-core-split-regions-for-min_nr_regions.patch mm-damon-vaddr-do-not-split-regions-for-min_nr_regions.patch mm-damon-test-core-kunit-add-damon_apply_min_nr_regions-test.patch mm-damon-add-config_damon_debug_sanity.patch mm-damon-core-add-damon_new_region-debug_sanity-check.patch mm-damon-core-add-damon_del_region-debug_sanity-check.patch mm-damon-core-add-damon_nr_regions-debug_sanity-check.patch mm-damon-core-add-damon_merge_two_regions-debug_sanity-check.patch mm-damon-core-add-damon_merge_regions_of-debug_sanity-check.patch mm-damon-core-add-damon_split_region_at-debug_sanity-check.patch mm-damon-core-add-damon_reset_aggregated-debug_sanity-check.patch mm-damon-tests-kunitconifg-enable-damon_debug_sanity.patch selftests-damon-config-enable-damon_debug_sanity.patch mm-damon-tests-core-kunit-add-a-test-for-damon_commit_ctx.patch docs-mm-damon-design-document-the-power-of-two-limitation-for-addr_unit.patch mm-damon-core-remove-damos_set_next_apply_sis-duplicates.patch mm-damon-core-use-time_before-for-next_apply_sis.patch mm-damon-core-use-time_after_eq-in-kdamond_fn.patch mm-damon-core-use-mult_frac.patch mm-damon-tests-core-kunit-add-a-test-for-damon_is_last_region.patch mm-damon-core-clarify-damon_set_attrs-usages.patch mm-damon-document-non-zero-length-damon_region-assumption.patch docs-admin-guide-mm-damn-lru_sort-fix-intervals-autotune-parameter-name.patch docs-mm-damon-maintainer-profile-use-flexible-review-cadence.patch docs-mm-damon-index-fix-typo-autoamted-automated.patch