From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752672AbZHZSWj (ORCPT ); Wed, 26 Aug 2009 14:22:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752482AbZHZSWh (ORCPT ); Wed, 26 Aug 2009 14:22:37 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:52953 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbZHZSWh (ORCPT ); Wed, 26 Aug 2009 14:22:37 -0400 Date: Wed, 26 Aug 2009 14:22:36 -0400 From: Christoph Hellwig To: Jan Kara Cc: Christoph Hellwig , LKML , Evgeniy Polyakov , ocfs2-devel@oss.oracle.com, Joel Becker , Felix Blyakher , xfs@oss.sgi.com, Anton Altaparmakov , linux-ntfs-dev@lists.sourceforge.net, OGAWA Hirofumi , linux-ext4@vger.kernel.org, tytso@mit.edu Subject: Re: [PATCH 07/17] vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode Message-ID: <20090826182236.GA1290@infradead.org> References: <1250697884-22288-1-git-send-email-jack@suse.cz> <1250697884-22288-8-git-send-email-jack@suse.cz> <20090819162638.GE6150@infradead.org> <20090820121531.GC16486@duck.novell.com> <20090820162729.GA24659@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090820162729.GA24659@infradead.org> User-Agent: Mutt/1.5.19 (2009-01-05) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 20, 2009 at 12:27:29PM -0400, Christoph Hellwig wrote: > Maybe you can help brain storming, but I still can't see any way in that > the > > - write data > - write inode > - wait for data > > actually is a benefit in terms of semantics (I agree that it could be > faster in theory, but even that is debatable with todays seek latencies > in disks) Btw, another reason why our current default is actively harmful: barriers With volatile write caches we do have to flush the disk write cache in ->fsync, either implicitly by a metadata operation, or explicitly if only data changed. Unless the filesystems waits itself for the data to hit the disk like XFS or btrfs will be issue the cache flush potentially before the data write has actually reached the disk cache. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id n7QILrXM030127 for ; Wed, 26 Aug 2009 13:22:08 -0500 Date: Wed, 26 Aug 2009 14:22:36 -0400 From: Christoph Hellwig Subject: Re: [PATCH 07/17] vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode Message-ID: <20090826182236.GA1290@infradead.org> References: <1250697884-22288-1-git-send-email-jack@suse.cz> <1250697884-22288-8-git-send-email-jack@suse.cz> <20090819162638.GE6150@infradead.org> <20090820121531.GC16486@duck.novell.com> <20090820162729.GA24659@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20090820162729.GA24659@infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Jan Kara Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, linux-ntfs-dev@lists.sourceforge.net, LKML , Joel Becker , Christoph Hellwig , Anton Altaparmakov , OGAWA Hirofumi , Evgeniy Polyakov , xfs@oss.sgi.com, ocfs2-devel@oss.oracle.com On Thu, Aug 20, 2009 at 12:27:29PM -0400, Christoph Hellwig wrote: > Maybe you can help brain storming, but I still can't see any way in that > the > > - write data > - write inode > - wait for data > > actually is a benefit in terms of semantics (I agree that it could be > faster in theory, but even that is debatable with todays seek latencies > in disks) Btw, another reason why our current default is actively harmful: barriers With volatile write caches we do have to flush the disk write cache in ->fsync, either implicitly by a metadata operation, or explicitly if only data changed. Unless the filesystems waits itself for the data to hit the disk like XFS or btrfs will be issue the cache flush potentially before the data write has actually reached the disk cache. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Wed, 26 Aug 2009 18:22:47 -0000 Subject: [Ocfs2-devel] [PATCH 07/17] vfs: Introduce new helpers for syncing after writing to O_SYNC file or IS_SYNC inode In-Reply-To: <20090820162729.GA24659@infradead.org> References: <1250697884-22288-1-git-send-email-jack@suse.cz> <1250697884-22288-8-git-send-email-jack@suse.cz> <20090819162638.GE6150@infradead.org> <20090820121531.GC16486@duck.novell.com> <20090820162729.GA24659@infradead.org> Message-ID: <20090826182236.GA1290@infradead.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jan Kara Cc: Christoph Hellwig , LKML , Evgeniy Polyakov , ocfs2-devel@oss.oracle.com, Joel Becker , Felix Blyakher , xfs@oss.sgi.com, Anton Altaparmakov , linux-ntfs-dev@lists.sourceforge.net, OGAWA Hirofumi , linux-ext4@vger.kernel.org, tytso@mit.edu On Thu, Aug 20, 2009 at 12:27:29PM -0400, Christoph Hellwig wrote: > Maybe you can help brain storming, but I still can't see any way in that > the > > - write data > - write inode > - wait for data > > actually is a benefit in terms of semantics (I agree that it could be > faster in theory, but even that is debatable with todays seek latencies > in disks) Btw, another reason why our current default is actively harmful: barriers With volatile write caches we do have to flush the disk write cache in ->fsync, either implicitly by a metadata operation, or explicitly if only data changed. Unless the filesystems waits itself for the data to hit the disk like XFS or btrfs will be issue the cache flush potentially before the data write has actually reached the disk cache.