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 D690B3D1CD4 for ; Fri, 20 Mar 2026 17:50:26 +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=1774029027; cv=none; b=OpAS0wT/DucdesF1/yZ7i0Mi7Jk1xszYLWyr/+a6tjiwZ7UQU1mzTzcO/4jb8HBD85DDFlIsxJA6STl/6AcLT2RLHLcUJf3D/lv0mla0gTfHFcIQ4PV5F0XxfIiaLnysejToak1Sx+kSB3iuf0VcGz9nVYg/ZsygOF6WilAj514= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774029027; c=relaxed/simple; bh=Yo/ULNgyG4/4Y5nhdNiIzlj7yThHIURYD0GE+zfMPpE=; h=Date:To:From:Subject:Message-Id; b=A34izks1JptFQNzyHn14JMxyz/qiq3wyWiCVXqAXyYZZbmYuFG5Tfk8NuWpPWmtftv7uQsoMm4dyY2WeYjf1Novwk1nJuEOTC/1KVqF/bmh1U21cPLVi5xGJxcRJ+gYsDnFjDQROuhf7/6ozsdRwmxspEafTGIGhcSCBYSs6QUM= 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=vrlSLYua; 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="vrlSLYua" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FF21C4CEF7; Fri, 20 Mar 2026 17:50:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774029026; bh=Yo/ULNgyG4/4Y5nhdNiIzlj7yThHIURYD0GE+zfMPpE=; h=Date:To:From:Subject:From; b=vrlSLYuaWif6D81+LU5T7wkPm9S7kOvloDzxMZBnpO4ZVddP0a4kX2brItuo09CQP Ni3CxgaG/kmOgPe0AcQV1TsDdBCrHnwZbvAgppmZuu0dsQy3EsLObmjso0pctxhlZu RtoTJ2Vuqs4cc91YtSJVi7da735h99+QyNFD+YyQ= Date: Fri, 20 Mar 2026 10:50:25 -0700 To: mm-commits@vger.kernel.org,sj@kernel.org,akpm@linux-foundation.org,objecting@objecting.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-damon-core-document-damos_commit_dests-failure-semantics.patch added to mm-new branch Message-Id: <20260320175026.1FF21C4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/damon/core: document damos_commit_dests() failure semantics has been added to the -mm mm-new branch. Its filename is mm-damon-core-document-damos_commit_dests-failure-semantics.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-document-damos_commit_dests-failure-semantics.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: Josh Law Subject: mm/damon/core: document damos_commit_dests() failure semantics Date: Fri, 20 Mar 2026 07:36:45 -0700 Add a kernel-doc-like comment to damos_commit_dests() documenting its allocation failure contract: on -ENOMEM, the destination structure is left in a partially torn-down state that is safe to deallocate via damon_destroy_scheme(), but must not be reused for further commits. This was unclear from the code alone and led to a separate patch [1] attempting to reset nr_dests on failure. Make the intended usage explicit so future readers do not repeat the confusion. Link: https://lkml.kernel.org/r/20260320143648.91673-1-sj@kernel.org Link: https://lore.kernel.org/20260318214939.36100-1-objecting@objecting.org [1] Signed-off-by: Josh Law Cc: Andrew Morton Reviewed-by: SeongJae Park Signed-off-by: SeongJae Park Signed-off-by: Andrew Morton --- mm/damon/core.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) --- a/mm/damon/core.c~mm-damon-core-document-damos_commit_dests-failure-semantics +++ a/mm/damon/core.c @@ -1060,6 +1060,23 @@ static void damos_set_filters_default_re damos_filters_default_reject(&s->ops_filters); } +/* + * damos_commit_dests() - Copy migration destinations from @src to @dst. + * @dst: Destination structure to update. + * @src: Source structure to copy from. + * + * If the number of destinations has changed, the old arrays in @dst are freed + * and new ones are allocated. On success, @dst contains a full copy of + * @src's arrays and count. + * + * On allocation failure, @dst is left in a partially torn-down state: its + * arrays may be NULL and @nr_dests may not reflect the actual allocation + * sizes. The structure remains safe to deallocate via damon_destroy_scheme(), + * but callers must not reuse @dst for further commits — it should be + * discarded. + * + * Return: 0 on success, -ENOMEM on allocation failure. + */ static int damos_commit_dests(struct damos_migrate_dests *dst, struct damos_migrate_dests *src) { _ Patches currently in -mm which might be from objecting@objecting.org are lib-maple_tree-fix-swapped-arguments-in-mas_safe_pivot-call.patch mm-damon-core-document-damos_commit_dests-failure-semantics.patch lib-glob-fix-grammar-and-replace-non-inclusive-terminology.patch lib-glob-add-explicit-include-for-exporth.patch lib-glob-replace-bitwise-or-with-logical-operation-on-boolean.patch lib-glob-clean-up-bool-abuse-in-pointer-arithmetic.patch lib-uuid-fix-typo-reversion-to-revision-in-comment.patch lib-inflate-fix-memory-leak-in-inflate_fixed-on-inflate_codes-failure.patch lib-inflate-fix-memory-leak-in-inflate_dynamic-on-inflate_codes-failure.patch lib-inflate-fix-grammar-in-comment-variable-to-variables.patch lib-inflate-fix-typo-this-results-to-the-results-in-comment.patch lib-bug-fix-inconsistent-capitalization-in-bug-message.patch lib-bug-remove-unnecessary-variable-initializations.patch lib-idr-fix-ida_find_first_range-missing-ids-across-chunk-boundaries.patch lib-decompress_bunzip2-fix-32-bit-shift-undefined-behavior.patch lib-ts_bm-fix-integer-overflow-in-pattern-length-calculation.patch lib-ts_kmp-fix-integer-overflow-in-pattern-length-calculation.patch lib-glob-initialize-back_str-to-silence-uninitialized-variable-warning.patch lib-bch-fix-signed-left-shift-undefined-behavior.patch lib-bch-fix-signed-shift-overflow-in-build_mod8_tables.patch