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=1794170179; b=ACuPWnE4IP1LYwX445nm3YbGGNOcs36iJAi494U21EhiZLkuHcGB0R4815lR6bbAFPbz e3v3z3wz/V0nN+hnBcBZ4oBw4wRpXN5NW2SoaeXSCInnLLpaY0pbRBOo/fnWmiWcruKQM gw3Po/oK807MtV5+NZWsRQMIB/CDZEDwI6Vo8pBy3D8EmoYX5/pup4xqcVRiJrTipSd7L qQHX1U3ZQvqsoott/k/txRRoQIgfmARsB414tib4okqpl9kpxJcDGS0L89Gv55N2hkGRv yDncpnPYfwOWYNxh9p9hluTEALQJnHCLLCSNSffUDScvUlQEbWjMwilemQ94AgHzD+w== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794170179; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=v8azARso06dhqTAeLMc7skppXLvcYQdPyeFCseSu9tM=; b=g7Ld1FhXqgwxmjC5hDtc110He7s7Rh1j/m1bZFsr+utaV3YF7KQ9GB9USvdPB0rGKNhC AKGauEliU1/gEDbevcdpeIWZnaf6uCheJYGEA5EAcHqOW11TGSAdHK+QnGOKJemCoaTN3 eEaHfXbid8nhBj2LtNYlqjB2detzWWHLzrPvLOhgsCT7z9Zb1Vo55KGKzZaXKNLnc8g9D da9qkVbLJRW25kEdckSNnNH58Sot1BRSQQ444TuhNxVZc/vYQO6frsa54DSdc/N75h4mw HTBJBQW4HJvkZqqzTk8KOh0R6OYIU4sJ7TNuXhX8Q9F5CLfGcGqIjefFdC/JAu443LQ== 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=A56ATWUD; 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 17285606A33C for ; Sun, 8 Nov 2026 20:36:19 +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=A56ATWUD Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA6B61F00922; Sun, 8 Nov 2026 20:36:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794170178; bh=v8azARso06dhqTAeLMc7skppXLvcYQdPyeFCseSu9tM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=A56ATWUD2D90WHekZBP0BIe/F6dic9aEjtoOn6sJPFtFP3mwM0xtLwIVElLK0lNCP 45ldKrwytJ/zbX8oPPWrnu85UUuHexiURgehqfGEdTjBXs0Qs5nIt40E+a0iCOgvmu vzlYx5HiifGa4nygHuRtaSuhQCWqu+Xkw/CuiBNE3S8Oruqq4bxJko6cXo3grOcS/X WwZT2cH3JqBHFsis3o+WJ/2ACN9yPIJ8jjkEv1Y631UbcW81mL7puYvHnsDHWyMGI5 plFVg9Ol5A7+06AHhA1Fvswu7LaG9u6tqqtW2pVGvhVPW4hBDbwR/E8llOWafozPD+ SJIFP0OLRcjIA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 6.1.y 1/2] 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: <20261108202759.117377-2-sj@kernel.org> References: <20261108202759.117377-1-sj@kernel.org> <20261108202759.117377-2-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 08 Nov 2026 20:36:18 +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: inflated tried stats in damon_do_apply_schemes() on split failure -- commit 3b087258b4341cba87012b7cb96ed676fd164c12 Author: SJ Park mm/damon/core: skip applying scheme if region split for quota fails This commit updates damon_split_region_at() to return an error code on allocation failure and skips applying the DAMOS scheme in damon_do_apply_schemes() when splitting a region to fit the 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 f0da5cb2b88a0..9206737d05ae7 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c [ ... ] > @@ -810,7 +810,8 @@ static void damon_do_apply_schemes(struct damon_ctx *= c, > 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; > } > ktime_get_coarse_ts64(&begin); > sz_applied =3D c->ops.apply_scheme(c, t, r, s); [Severity: Low] Does jumping to update_stat on damon_split_region_at() failure inflate s->stat.nr_tried and s->stat.sz_tried? When damon_split_region_at() fails, sz is the non-zero remaining quota size, c->ops.apply_scheme() is skipped, and quota->charged_sz is not advanced: mm/damon/core.c:damon_do_apply_schemes() { ... update_stat: s->stat.nr_tried++; s->stat.sz_tried +=3D sz; ... } Because quota->charged_sz remains unchanged, subsequent matching regions can repeatedly add sz to s->stat.sz_tried if allocation continues to fail. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261108202759.1173= 77-1-sj@kernel.org?part=3D1