From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kylie.crudebyte.com (kylie.crudebyte.com [5.189.157.229]) (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 D3CEA3ED105; Wed, 4 Feb 2026 12:04:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=5.189.157.229 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770206656; cv=none; b=AewFP6zwKFuu+4ZFJh6CSlpeJSVnR2mTBVIUDir1gjg2Z2avDdN84wvwE0an5rihqEcEo52ua5lBiIUTexTgbkk0TuCljd5WxOGIRHprBcREZVpuzpJZDTl7xPklY9xmU3rvsf2j4SXwxEZOs8v/WPSzlG63bYCdJQfh/JqqW7E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770206656; c=relaxed/simple; bh=7G/PwzIk3g4uIGdcJqA20KrJMGGg5TpRuyz/ChE2xac=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=icXkCsvyp8U7m1Iv+Rb8QlTU5+juSY6JptLVV46yX+0jBdXpqWP1J9y578koz0BwBA3JMcV7oAMNUgH3Kraajxk1whWTc9gxe5ToGFU/m8DI1N1FOGGXAw1NeAbtivHbDQEHCt9vxYUgJO7iXPdwDlCQW8aSFXbce2bs9b1lTQ4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=crudebyte.com; spf=pass smtp.mailfrom=crudebyte.com; dkim=pass (4096-bit key) header.d=crudebyte.com header.i=@crudebyte.com header.b=AZSOnMie; arc=none smtp.client-ip=5.189.157.229 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=crudebyte.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=crudebyte.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (4096-bit key) header.d=crudebyte.com header.i=@crudebyte.com header.b="AZSOnMie" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=kylie; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Content-ID:Content-Description; bh=Q+Ks08PzHVA8pXNev8uKWfCnJ6OcTFhczPTs0oqi89M=; b=AZSOnMie4dVcjCOeODKz4Zoxz2 7ozRS3+UpFV3dz8fQWwx4MRQCqx8EZdSUlQy9wfvjeT1edNHzmGMg6V4L+s4p5d6DeBz+fDC6MBWm SQR4I+C2LEaUpn4f+RI6u4oX1eRpa1XLY3uoLinNmp9TPAio4wlaBBcQQICxbNjlPYQKPNeOp3u8h bHqZSoyKqNoauavjA7QUNPPveR2zwQiM7TgMXCoQsYvoQOY3dosMhNFBrAwxmoEKlHcXI5+R2WPKc KFxNVDbiy6dRu5hjxZM/IzfAt8oWS/8NBfsS6IZH3OVt81yj0trwXyuNi230F0zdBM6q7wOGDRNAf yCrdXMsYT4hOM+WzmhGD3pI93xh7S+oOkEe+mOMurAAajyGUJ6H/mer9PS1kjKOr6vSu/anOtSKaU BMClTz45J/5xzVksHMjaT3JEhz8HZV1A8zd8gPzx/pGNo1EKMoI46dC64ZCm5SLQUX9NfXv/gE1Vk O0l9haMVubcIq5eM8DdGRRWu8LEK38Nz4oSl+98tYEu0fgJS2YVVSx9h8YnMxfoDPygOQZSHAjoWg TxEav8G/iSIdYe535wH3L5J9SWh+uxIu4G0v/28tpU0A6SxWy5EMpbM8Wkgn/pzwbNl9PGNetVXJK nOIXLcHrFmMYeAmh905U3bbXF+gl02CLOzIrzTCSo=; From: Christian Schoenebeck To: v9fs@lists.linux.dev, Remi Pommarel Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Eric Van Hensbergen , Latchesar Ionkov , Dominique Martinet , Remi Pommarel Subject: Re: [PATCH v2 0/3] 9p: Performance improvements for build workloads Date: Wed, 04 Feb 2026 12:37:55 +0100 Message-ID: <4711141.LvFx2qVVIh@weasel> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" On Wednesday, 21 January 2026 20:56:07 CET Remi Pommarel wrote: > This patchset introduces several performance optimizations for the 9p > filesystem when used with cache=loose option (exclusive or read only > mounts). These improvements particularly target workloads with frequent > lookups of non-existent paths and repeated symlink resolutions. [...] > Here is summary of the different hostapd/wpa_supplicant build times: > > - Baseline (no patch): 2m18.702s > - negative dentry caching (patches 1-2): 1m46.198s (23% improvement) > - Above + symlink caching (patches 1-3): 1m26.302s (an additional 18% > improvement, 37% in total) > > With this ~37% performance gain, 9pfs with cache=loose can compete with > virtiofs for (at least) this specific scenario. Although this benchmark > is not the most typical, I do think that these caching optimizations > could benefit a wide range of other workflows as well. I did a wide range of tests. In broad average I'm also seeing ~40% improvement when compiling. Some individual sources even had 60% improvements and more. So there is quite a big variance. I did not encounter misbehaviours in my tests, so feel free to add: Tested-by: Christian Schoenebeck I still need to make a proper review though. /Christian