From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A684337A85B for ; Wed, 9 Sep 2026 06:09:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788934193; cv=none; b=EvErsP5t5fwBBYctOAkDqqkw6mNlyuZHqbpekSJPZtF5xPQZUWidF/FrWaeYOHG/0coiaXhOXr6ID49K7GgwT32KVvBeDA8m0WGJUdAC+sGGlJxqzokxW0Vqd4oNCryNIwSVf0oZTHgtZnQS13C16YJC25mghtJpzyVOJDUrpZI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788934193; c=relaxed/simple; bh=UGQkYUazrpj031r8kqWKTOgJwQzwX6Cm3VPhRQ4htOA=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=jTkyGe7EZ65c3u/4B2u+3nNL/mKdbbAQ6A7mVkk2xCSt00GyPTkkPUQU0rr8X54E/6npyH+vIrBwU7pcenyGDvfNBhOTx6D742MgPivwHgTwixqzXKyR7myA3iSS1k5HSxK4md57vYAZPJGBo2kTrdtucrBDz1PPNyXqjHdWXmQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PTOBUFXi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PTOBUFXi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20DBF1F00A3A; Wed, 9 Sep 2026 06:09:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788934192; bh=qvx2j22l8GXu1OSJkFq6NGF85LOReDLubjLySpYO5Lk=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=PTOBUFXivCgRjcGo41r1Tz3QGtWRKNZB+qWeyB2laAV3/3glFH3JNUV4ljHYDMA++ omfqLQ+66uRRoj7UsitRvMEufOKm96EeWVAgbP5+7bAT6kqxwF55/vBcBCIyFpdjnJ PhXk91gscKd0qp1hY1azaSsQ8KNXSrTZ4lEq9oDQwR9DNNosxLF6ECcJ2sqV3cYyut smkoOMDnG3J9rbFG4MzMRQ6ilyE52PMeZyjgsLHFvZLPltneznLl+jYTLvGG/FPc4T gfTATWrlrMKInf9a6kvztBOlGgLNiwzfFiuqvmK3Zw27BopEnY6ZIYTpFI7u/i2xSg o/HyWuqnNLSQw== From: sashiko-bot@kernel.org Subject: Re: [PATCH 6.12.y] mm/damon/vaddr: drop last same folio access check optimization Reply-To: sashiko-reviews@lists.linux.dev To: "SJ Park" Cc: damon@lists.linux.dev In-Reply-To: <20260909060130.269798-1-sj@kernel.org> References: <2026090858-underwent-outlying-c364@gregkh> <20260909060130.269798-1-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 09 Sep 2026 06:09:51 +0000 Message-Id: <20260909060952.20DBF1F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: > The optimization can race when multiple kdamonds are running. Meanwhile, > the impact of the optimization is quite doubtful. Just remove it. >=20 > The user impact of the issue should be quite trivial. After all, the race > can happen only when the user intentionally setup DAMON in the way. Even > if it happens, it would be rare and only degrade the best-effort > monitoring results. No critical consequences like kernel panic or memory > corruption happen. >=20 > The race possibility was discovered [1] by Sashiko. >=20 > Link: https://lore.kernel.org/20260715031002.108504-4-sj@kernel.org > Link: https://lore.kernel.org/20260621204050.10993-1-sj@kernel.org [1] > Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memo= ry address spaces") > Signed-off-by: SJ Park > Cc: # 5.15.x > Signed-off-by: Andrew Morton > (cherry picked from commit 831846078caa14b7d00b2ccca8b8fe522afe3204) > Signed-off-by: SJ Park Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260909060130.2697= 98-1-sj@kernel.org?part=3D1