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=1794088357; b=Up8JlicTG49uuclhb19Xnb5Tt8gK2SjB4nqa4NnxO+oRYHoB6V9Yu8R+nZ0WGHpNIbF0 g+La/SZYchd/I/mL6Ke2UIONEfi86quBBlwz9H9uIgyN+15+uf8YYVV9EQ48K7xmz24AT 2iHqVhNL1nFCRkh8ZdkGjYf+aVo3yyBaXQYGXwgb5x0MSbgh6aJI6AKUO0AnyiupovcDc FRJ8dcAxKOTfUBMC9eej0PiCaO8kZLa51vf1sHKDx9zser1pNgUGOc0dDLIWeAB9CYIvC QXvwMUD/PBKSufbOgAzz9HHULK6aJNX8wdfx9RSCyjnNU+rG5Rr5fgMeIBUvRPQ/D3g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794088357; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=MTFE5k+b3EPTf9xyiP1cwm3DBnq7vMvtd/XV5WMMTdY=; b=Ub49PFH0YCGFNjKPqjviR/8PQEW1gThV45cjyrMq22PGDE7ZIKnptmNkmGm4V0M5FSn0 O4Hq/b/ROM02sdl36zJ8YDB5ZcPdUqZWMOgPslR8Bn47DoQgVWQkTL9Owz3fEgc5eaTRF 47OdkGQ5IHFuxFZHdPOK763hJcjJER+OZvf8xuTVzG8y7flkdHBwGlNK9SA8P6X1Riiqs RiHzrEhr/ZF+F0v0kNeerDFetJX+suNze6jzvWX3SrCHO3UBK2kFwiPtO6QKvsv5j/MjK LevBg+KWv2s+jvuhg0DiMTb7PfJWo6QsY0XeWotwuGqmMH/wqobwkL0fHMcsfb9Mr/Q== 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=d+RQyBut; 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 A98CC606A326 for ; Sat, 7 Nov 2026 21:52:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=d+RQyBut Received: by smtp.kernel.org (Postfix) with ESMTPSA id 475821F0089F; Sat, 7 Nov 2026 21:52:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794088356; bh=MTFE5k+b3EPTf9xyiP1cwm3DBnq7vMvtd/XV5WMMTdY=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=d+RQyButyz311+aKUVi3R/oni5G31LOAlqLgmIYGvO45yPVIki9StDy04ib5P03tJ lf3BY8sV1prihECfE6gbUY9LU9qcyosU4coe97/LccZqOSW2DmgoPhjCw4dqxo9w1H tOZVL43VOz30ALf0dXSl9LKZE1iHRIitrsO9dPdW/UdAK61v9qGFve55nc4VVAE1A6 8xQJRealNcFQ5+ZS5ZePB0KKmxoPaxllCYnjlIZlWF8SGXXhwrJRATX+QjwitLCw+t 1LmpLcNQEk5dOWVgoCG6fRxpRvx8swZw820IV3DEV6J+jCEJSdqBWUxJEWsMhBrCe9 gspFPGdYcA0tQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH 6.12.y 1/5] mm/damon/core: skip applying scheme if region split for quota fails Reply-To: sashiko-reviews@lists.linux.dev To: "SJ Park" Cc: "Andrew Morton" , "Usama Arif" , damon@lists.linux.dev, linux-mm@kvack.org In-Reply-To: <20261107214525.304638-2-sj@kernel.org> References: <20261107214525.304638-1-sj@kernel.org> <20261107214525.304638-2-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 07 Nov 2026 21:52:35 +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 to consider: - [Low] mm/damon/core: inaccurate tried stats on split failure in damos_apply_scheme() -- commit fe019f891ca813eff979dfc83e95ba297bc45135 Author: SJ Park mm/damon/core: skip applying scheme if region split for quota fails This commit changes damon_split_region_at() to return an error code on allocation failure and skips applying the DAMOS scheme in damos_apply_scheme() when splitting a region to fit the remaining size quota fails. Link: https://lore.kernel.org/20260901131850.98037-1-sj@kernel.org Link: https://lore.kernel.org/20260901131850.98037-2-sj@kernel.org Link: https://lore.kernel.org/20260718171523.87547-1-sj@kernel.org [1] > diff --git a/mm/damon/core.c b/mm/damon/core.c > index 81d44e41de210..6ef77741b783b 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c [ ... ] > @@ -1470,7 +1470,8 @@ static void damos_apply_scheme(struct damon_ctx *c,= struct damon_target *t, > DAMON_MIN_REGION); > if (!sz) > goto update_stat; > - damon_split_region_at(t, r, sz); > + if (damon_split_region_at(t, r, sz)) > + goto update_stat; > } > if (damos_filter_out(c, t, r, s)) > return; [Severity: Low] Should this return instead of jumping to update_stat when damon_split_region_at() fails? At this point sz holds the non-zero aligned remaining quota, and update_stat calls damos_update_stat(s, sz, sz_applied), which increments s->stat.nr_tried and adds sz to s->stat.sz_tried even though scheme application and filter evaluation were skipped. Because quota->charged_sz is not updated on this error path, persistent allocation failures across subsequent regions larger than the remaining quota will repeatedly add the remaining quota sz to s->stat.sz_tried and increment s->stat.nr_tried. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261107214525.3046= 38-1-sj@kernel.org?part=3D1