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 D6FBB344DA0 for ; Thu, 3 Sep 2026 02:23:32 +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=1788402215; cv=none; b=IFtG5sBqxHh9HpoZs8FxV7CSfIoC13XSCaAViRcBBdVCSN0hnKZxUEO6YIUrLG+u8kkPM7dJsC6Ycq+9+qm6FF7ZubKaZ/JnhvzbRr2xfJJX+4Hlb65ZsnL3qTz7FYzNQdYCDovbScngp8C8p4wg4jAjmKYSi1Nj2QtrmXyj2QI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788402215; c=relaxed/simple; bh=kQwD1zOrDnHSVKYV2ychBaOKVb2gfKy15sYwkGwGc2c=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=ILx29P2KOko5q6uQU0Mn9dw7+4kNd5JLpJK+UPenweA3KzrjixwAG4TiLSxYimClMfZ8YqgNSgCPzb1s0MUHj4uUlNRIKszW7Rv5y9jAlu9Ld3nWMKGaRt9GuPt32P/zIJHe2BhASVlMx4JNSuXlLr9lRRsQq184VC/71Nu6tY4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QcppnAB8; 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="QcppnAB8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 335811F000E9; Thu, 3 Sep 2026 02:23:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788402211; bh=ge3KriVRvJ/H/37yU2E9wS1Y0lqq5KOxqVSDXcFkKCw=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=QcppnAB8xLSvbbNEaRaw0/d61UxNWMPTI5kf1w8ONC1pNARpCYL5BYxVPk3a6XO6+ H5IdEqjtQ5EiSYPpZaQBvKAKbheOCsaXev+flGEQv3e/45NXEj9PawTYuUDya56oiP DvgSeyj+QFa6mWbL7laPN+gX7PHNL3RF+B+qtkutv7WUws+88ZirF/rpf5FS1DJvvw uqxsgKcsfd331cOM1AxGK9vKtOtrc+MNxyNPv87DgCnZptjMlY0X8zAi7iI5v+FHGM VvIg8oEqdLpgS7XXmji90JmOG611vPRfQcChNY6f3mt06wqawEWG19KpAj9AJpJ3x7 ZtIi5O38jan2Q== From: sashiko-bot@kernel.org Subject: Re: [PATCH] ext4: isolate s_orphan_lock from read-mostly fields Reply-To: sashiko-reviews@lists.linux.dev To: JonasZhou-oc Cc: linux-ext4@vger.kernel.org, tytso@mit.edu In-Reply-To: <20260903021836.962624-1-jonaszhou-oc@zhaoxin.com> References: <20260903021836.962624-1-jonaszhou-oc@zhaoxin.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 03 Sep 2026 02:23:30 +0000 Message-Id: <20260903022331.335811F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > From: Jonas Zhou >=20 > s_orphan_lock is modified by orphan-list operations, but currently shares > a cache line with s_journal and s_ext4_flags. The latter fields are read > from common ext4 paths, so unrelated accesses can cause the line containi= ng > the lock to bounce between CPUs. >=20 > On a two-socket Intel Xeon Silver 4208 system with 16 workers, throughput > improved by 4.6% for stress-ng.dnotify and 1.7% for stress-ng.unlink. Pe= rf > c2c showed that HITM events on the affected fields decreased from 3,699 to > 3,125 (-15.5%) for stress-ng.dnotify and from 1,368 to 571 (-58.3%) for > stress-ng.unlink. Remote HITM events decreased by 45.1% and 65.5%, > respectively. The journal/flags line had no remote HITM events after the > change; the remaining remote HITM events were on the orphan-lock line. >=20 > Signed-off-by: Jonas Zhou Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260903021836.9626= 24-1-jonaszhou-oc@zhaoxin.com?part=3D1