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=1794168021; b=tuGLx3KPul9ehzG69GZPfKbB9Nj6iirZ8nVAhKibi/QZ4ok9JIs48m8hsMzYfgrLqx5a 4tJiqK0W9lpgPCx0SCrU/jkXJ2WIc4mMfaBIKYAJsla6NTA2Yu+IB1TuxGqlMy4d+0hxg d1Tv9b5K/BuiOtuQaDItIN6lxIeuYqCAtzCHvFeufwjsLOw0L7NA4eyQLqe5z+7WEbpRs mjAr6fbTZqo+CoyWSahAJGx2ppbXsOke6qPRceI+insQN4p3IfN96OydkM5VQ2MRgDxFC UgOqhD7cDn+ybkl9kCJ7D7f9ndnfYq+zIk2qyG9SuoP2nHMThl5WGcyjEKkVFDeC95Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794168021; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=0t1IoikLmQeJOs13YrNXpWqFQtdpP6egbT1Ng/ntwIA=; b=UNhPDhc7vZ7PkIwD+NfaICjPKmUsklg69L0t9UZzwVWWOoas/Nmhc5kIErdJD991K5zu NgZz1lrNF/1cnTz04/Vwtxpfj7pvWLxxB/m597HScRjiXCf1g6xO14j51UQOhXiZvzg4r tQq47MN66nNkbwUBwXIfI+PS81+BqOxvyg/J5kfmWMyTgq9tV2b1jQW/wh8Ck/cHRrbiF rnM8hq9W+VfTb8g4x4y+BAyFHxiQMlmNGXw66yNhwBxb+lWXQ/KGVp3pncjgwNSS+H4XV EYOyBMVnUnoHaqW6EToZ75auk+cjUnWLJo0YbtzRJJquFvf8EIU/3ui7odhcaU0YGOQ== 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=K54YUwye; 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 6D398606A31C for ; Sun, 8 Nov 2026 20:00:21 +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=K54YUwye Received: by smtp.kernel.org (Postfix) with ESMTPSA id BEAE41F0089F; Sun, 8 Nov 2026 20:00:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794168021; bh=0t1IoikLmQeJOs13YrNXpWqFQtdpP6egbT1Ng/ntwIA=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=K54YUwyeUgUB0aOnJcNqp57726P1hkg51pByTxgZXqeo39/89w82Rg3A/ypQm5hN/ db/DOqQY+zLjSGmUn02Tu8YsLlae6+ReMNYsvDQ2H6kTUFBgTOZ+jMcVspJtVROhdn qDKWycKOfBP28WS8DRQqrtmkNU/YHv3m4xsKmW1czIcBwmZOGjmibTCGh10rQfBssz VfE0QpaEQxJXw3XmTZnhr8JWRxe9i4lF9Cg33Ps15+KSqZdScNDNXjrnIldFORJsu6 5XtFrTwAuefHPMDiwxdE6V4iHKDOb40h7n/HW2HSlhUrK9vLjZIpfoTYF7bqSMJUJw tIYiPApzBZhsA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [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: <20261108195145.115792-2-sj@kernel.org> References: <20261108195145.115792-1-sj@kernel.org> <20261108195145.115792-2-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 08 Nov 2026 20:00:20 +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 2d3797cf5f053ac8bc0b4587f17ff69eb9813ce6 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 damos_apply_scheme() when splitting a region to fit within 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] Does jumping to update_stat when damon_split_region_at() fails inaccurately inflate s->stat.nr_tried and s->stat.sz_tried? At this point sz holds the non-zero remaining quota, so damos_update_stat() increments s->stat.nr_tried and adds sz to s->stat.sz_tried even though scheme application and damos_filter_out() were skipped. Because quota->charged_sz is not updated on this failure path, any further matching regions that also fail to split in the same walk will repeatedly add the remaining quota to s->stat.sz_tried. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261108195145.1157= 92-1-sj@kernel.org?part=3D1