From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793705384; b=yus7OLMrnRcCKj60s83P5yyr4Q2/XUl5ZjQ8ArckteIDSfnNxHSo39k2B75yNqZKbjtA yD2QdfXhNMN1PAiUggDwPFQLfNYLvlr8LuAWnCqQ4x66HUBdGZ+ekkaWl9B1sHOu8Owbg /H+9eWHBdtYJYpgHGFYQn5WEstoslOUZM4T2Xwpgy5jBOVcCt1DNNHi0qbdUXxcQPrQPm Pesu7wHbOIXkyLA4wibFufHMHwqjmpZdHgeLet68bXgCKTHVjzAaTlIrod+8saJcyUz/c 2uPbVVqg5mMC084RQLTjnK7DCGTCRVDu9MXXboMY7ixF4gozVw2mZPUdK0FikPWnPGA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793705384; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=pLKPltpOKrJeivfZ4qfED8CPkzZvz3KzKJEccxtQyxE=; b=RgBdLYMebJiCdsXFef+ZVHnOl+qPvXyCwP2j2zjP4RtzJ+hOl7NgsaSuoFLPt7ly2jkO FGWO0uNZfNts15wnouMCrLjC9nrrCpXdyuKP4ejFYI5fkUUsf3hYJAJYJ4JPS4lNurxKb IXF9+CGU6cKTCwAo1ySx0T4KALmfBnNMIf331BfwJc5iiB40GMVk0Pfraad9h4VG+yjMA 4ASaIFSE6OBM5Xbb4JZeXlI9p5AOQflAJg0dKnwdzzb7gSy4N2/4RY92FTgxkJDUJrGLn e830gdR+n6kYq6+fVwuP5MVcWraiPrq7CK0CZXbH/bEoATUuHcP7I4pLRtYqqI14VQw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=eM3VbPfa; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B451606C541 for ; Tue, 3 Nov 2026 11:29:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=eM3VbPfa Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5504E1F00A02; Tue, 3 Nov 2026 11:29:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793705384; bh=pLKPltpOKrJeivfZ4qfED8CPkzZvz3KzKJEccxtQyxE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=eM3VbPfa7wawjF5nU6A0ctvbSq1HaIv3xtC3m8UTaP+3sc7J4X6m+MLj/JKQGSQu0 OiesQyiWwiKBh7oCBbcaH6/AgHm++Si8ln0YhocGDY/M6zemUy1kIEwDqbpKmRNs6m 2fftZ2T7Z3A9xzMcS6AXJ23fPzULtvF8MJBBj1NOGrEJmKikk4WIVp4eBr7KyVcY5b Rc3t9oLEtEOewXvnPCM0uO6hSb18zNgjDPPWT0ZWnrkyG9Ik/0Rhhgive9Gm6m+SB1 FlG+EKGkaHO7VcVPez/Ee8kweyKH/fquCZB4Eg8uumIscXyljJ1H4hBGuM6mUeI5Kc ZMkLVIMh6TlJw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH] mm/damon/core: reject empty access pattern intervals on scheme commit Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?WGlhb2xlaSBXYW5nIChLYWlob25nKQ==?= , sj@kernel.org, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, error27@gmail.com Cc: damon@lists.linux.dev, linux-mm@kvack.org, "Liam R. Howlett" , "Michal Hocko" , "Mike Rapoport" , "Suren Baghdasaryan" , "Vlastimil Babka" In-Reply-To: <20261103105418.362459-1-xiaoleiwangxiaolei@gmail.com> References: <20261103105418.362459-1-xiaoleiwangxiaolei@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 03 Nov 2026 11:29:42 +0000 X-Mailing-List: damon@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [Medium] mm/damon: damos_validate_scheme() breaks DAMON sysfs.py selftest -- commit f1effb4d8401c0508f7cb04b14b9b55d0d6abd17 Author: Xiaolei Wang (Kaihong) mm/damon/core: reject empty access pattern intervals on scheme commit This commit introduces damos_validate_scheme() and calls it at the start of damos_commit() to reject DAMOS schemes with reversed access pattern bounds (min > max) or non-monotonic watermark thresholds with -EINVAL. > diff --git a/mm/damon/core.c b/mm/damon/core.c > index d36823f4d0928..9b2b2a63a2576 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -1561,10 +1561,29 @@ static struct damos *damon_nth_scheme(int n, stru= ct damon_ctx *ctx) > return NULL; > } > =20 > +static int damos_validate_scheme(struct damos *s) > +{ > + struct damos_access_pattern *p =3D &s->pattern; > + struct damos_watermarks *wmarks =3D &s->wmarks; > + > + if (p->min_sz_region > p->max_sz_region || > + p->min_nr_accesses > p->max_nr_accesses || > + p->min_age_region > p->max_age_region) > + return -EINVAL; [Severity: Medium] Does this validation break the existing DAMON sysfs kselftest in tools/testing/selftests/damon/sysfs.py? In tools/testing/selftests/damon/sysfs.py, main() constructs a non-default scheme for testing online parameter commitment with min_sz_region =3D 4096 = and max_sz_region =3D 1024: tools/testing/selftests/damon/sysfs.py:main() schemes=3D[_damon_sysfs.Damos( action=3D'pageout', access_pattern=3D_damon_sysfs.DamosAccessPattern( size=3D[4096, 2**10], nr_accesses=3D[3, 317], age=3D[5,71]), When main() subsequently calls kdamonds.kdamonds[0].commit() and assert_ctxs_committed(kdamonds), writing commit to the kdamond state sysfs file invokes: state_store() -> damon_sysfs_handle_cmd() -> damon_sysfs_commit_input() -> damon_commit_ctx() -> __damon_commit_ctx() -> damon_commit_schemes() -> damos_commit() -> damos_validate_scheme() Because p->min_sz_region (4096) > p->max_sz_region (1024), damos_validate_scheme() returns -EINVAL, causing kd.commit() in assert_ctxs_committed() to fail and exit with status 1: tools/testing/selftests/damon/sysfs.py:assert_ctxs_committed() if kd in kdamonds_paused_for_dump: err =3D kd.commit() if err is not None: print('pause fail (%s)' % err) kdamonds.stop() exit(1) Should tools/testing/selftests/damon/sysfs.py also be updated to use a non-empty size range (for example, size=3D[4096, 2**20]) so the selftest continues to pass? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261103105418.3624= 59-1-xiaoleiwangxiaolei@gmail.com?part=3D1