From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 A0660241665; Wed, 22 Oct 2025 05:34:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761111283; cv=none; b=XCaiRLXtAG9dr11EAhkJcNaa20i7hoi0CDccwZpNeIvkrhYmEDxaCHxEWFfa5HgFA6wq47J9kqgdrkQ4wR4Zh1+JM8wlMkoCclXLOMnjf9EBqkBVMKjkap2steguxKZm9zkZA89VcrjZNy4dwnKaJmHznQSKwDw0jj900sdNjY8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761111283; c=relaxed/simple; bh=gsDXUURKh7jMSr5chgzvZQTNTnV3Qsf+wVti7kG94X8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cxW8znAZjJgGdxVkAxfcY43wHUXxCstdJ4/1kiVCJzEr09CObD6lFgLFEaexHcTsminEpElY2bCMWlNYorQirO48YPSbBU1UcHlvaMeapzKb5KtfvHxYWyoA4NZAHqSLBQQQqTv0XUU9/Et6VHUsn2s5F9rw+IzvQk5GsMT+R10= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 0582A227A88; Wed, 22 Oct 2025 07:34:35 +0200 (CEST) Date: Wed, 22 Oct 2025 07:34:34 +0200 From: Christoph Hellwig To: Christian Brauner , Jan Kara , Carlos Maiolino Cc: Andrew Morton , willy@infradead.org, dlemoal@kernel.org, hans.holmberg@wdc.com, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: allow file systems to increase the minimum writeback chunk size v2 Message-ID: <20251022053434.GA3729@lst.de> References: <20251017034611.651385-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251017034611.651385-1-hch@lst.de> User-Agent: Mutt/1.5.17 (2007-11-01) Looks like everything is reviewed now, can we get this queued up as it fixes nasty fragmentation for zoned XFS? It seems like the most recent writeback updates went through the VFS tree, although -mm has been quite common as well. On Fri, Oct 17, 2025 at 05:45:46AM +0200, Christoph Hellwig wrote: > Hi all, > > The relatively low minimal writeback size of 4MiB leads means that > written back inodes on rotational media are switched a lot. Besides > introducing additional seeks, this also can lead to extreme file > fragmentation on zoned devices when a lot of files are cached relative > to the available writeback bandwidth. > > Add a superblock field that allows the file system to override the > default size, and set it to the zone size for zoned XFS. > > Changes since v1: > - covert the field to a long to match other related writeback code > - cap the zone XFS writeback size to the maximum extent size > - write an extensive comment about the tradeoffs of setting the value > - fix a commit message typo > > Diffstat: > fs/fs-writeback.c | 26 +++++++++----------------- > fs/super.c | 1 + > fs/xfs/xfs_zone_alloc.c | 28 ++++++++++++++++++++++++++-- > include/linux/fs.h | 1 + > include/linux/writeback.h | 5 +++++ > 5 files changed, 42 insertions(+), 19 deletions(-) ---end quoted text---