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 2BB0238836C for ; Thu, 8 Oct 2026 19:29:13 +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=1791487755; cv=none; b=Rw9Fzd24vNfoBI09s4VnfFhkLTnMyLmfl+r3+YGuj1AACodftDHVGzP4QKjLIBkokot9AwvU3mkx9v59ntvyeg+b6+KZlb+f8Nh6QPyerm0quYR1gllfDfbVd0pzRhmT/Io3aMhEpSJlsLDz1QepB3wuduwYAjjT/NylcDfplvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791487755; c=relaxed/simple; bh=6V1ZP4+bq+zZZMzDKa5VkVnhBjXREQsHIDWTYK9YHhk=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=P0AWCMZX6GD9ir/dLmA2yZnzFFahtprjGZOfPYsXKrb7XQAWZJv+9uwK/zmQvp0Ywnm+OwDMbekBxZaAvQ+nwQWr1vL+aNMGkcka7+Lgce2fZsPHmkXnK+8juZ3sxvPsDGIMYyaMIdOsvPTH7dTbgYoIoUeGr020tkmeGT/STO4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J5WN6GAs; 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="J5WN6GAs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98B6A1F000FF; Thu, 8 Oct 2026 19:29:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791487753; bh=AkSNl0NxqWzRneN0RuvR8Ouvo+uRvL1PIYHNtI6kPM4=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=J5WN6GAslUvfVC8D3q3DxgAj4as2b0arhQZzxN6ZNB7de8WAkalwjZA2Oq1As+/en 4YGdZo3vh1hTSjxxM1ajaTpBZu4LfNgRlG1Dq3ZLL2AJOZFG6WcIpn+8ZI5mgvS5TZ PD1hn7MM6IeaCBBZAZLUbA/c7TwmDoeFYIh6cc3yOovgjznv5EKZn1d55zXbZFjkQO tlor4a5iI0LaXZNqQgZAOL7PIFYcN4wybEiHnH3P+Sg7R0P7IgjnJUQe9nGxlvg1Bu QcNYMeaNcE9SbjPps+6oMG99fHWa6abOHtfMF3iCRk4MMPraWcr5qqN1vy21YKGf9A dfnwjcj4Vp3Yg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 6.6.y 2/2] jbd2: bound shrinker scans by examined checkpoint buffers Reply-To: sashiko-reviews@lists.linux.dev To: "Artem Dinaburg" Cc: tytso@mit.edu, linux-ext4@vger.kernel.org In-Reply-To: <20261008192048.98833-3-artem@trailofbits.com> References: <20261008192048.98833-1-artem@trailofbits.com> <20261008192048.98833-3-artem@trailofbits.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 08 Oct 2026 19:29:13 +0000 Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: Max Kellermann >=20 > [ Upstream commit 15cb16496446b94e67f7abcb049b8e2c75cd3d02 ] >=20 > The jbd2 shrinker currently accounts only checkpoint buffers that it > successfully releases against nr_to_scan. Busy buffers therefore do not > consume the scan budget. >=20 > If a checkpoint transaction contains mostly busy buffers, the shrinker > can scan its entire checkpoint list while holding journal->j_list_lock. > Large checkpoint lists can result in excessive lock hold times and leave > other CPUs spinning on j_list_lock, causing soft lockups or RCU stalls. >=20 > Pass nr_to_scan into journal_shrink_one_cp_list() and decrement it for > every buffer examined, including busy buffers. Pass NULL from checkpoint > [ ... ] > Reviewed-by: Jan Kara > Link: https://patch.msgid.link/20260713102229.1598812-3-max.kellermann@io= nos.com > Signed-off-by: Theodore Ts'o > Assisted-by: LLM > Signed-off-by: Artem Dinaburg Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261008192048.9883= 3-1-artem@trailofbits.com?part=3D2