Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261434AbVEOQ4N (ORCPT ); Sun, 15 May 2005 12:56:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261643AbVEOQ4N (ORCPT ); Sun, 15 May 2005 12:56:13 -0400 Received: from one.firstfloor.org ([213.235.205.2]:27521 "EHLO one.firstfloor.org") by vger.kernel.org with ESMTP id S261434AbVEOQ4L (ORCPT ); Sun, 15 May 2005 12:56:11 -0400 To: Jeff Garzik Cc: gene.heskett@verizon.net, linux-kernel@vger.kernel.org, okuyamak@dd.iij4u.or.jp Subject: Re: Disk write cache References: <200505151121.36243.gene.heskett@verizon.net> <20050515152956.GA25143@havoc.gtf.org> <20050516.012740.93615022.okuyamak@dd.iij4u.or.jp> <42877C1B.2030008@pobox.com> From: Andi Kleen Date: Sun, 15 May 2005 18:56:09 +0200 In-Reply-To: <42877C1B.2030008@pobox.com> (Jeff Garzik's message of "Sun, 15 May 2005 12:43:07 -0400") Message-ID: User-Agent: Gnus/5.110002 (No Gnus v0.2) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 860 Lines: 20 Jeff Garzik writes: > > The ability of a filesystem or fsync(2) to cause a [FLUSH|SYNC] CACHE > command to be generated has only been present in the most recent 2.6.x > kernels. See the "write barrier" stuff that people have been > discussing. Are you sure mainline does it for fsync() file data at all? iirc it was only done for journal writes in reiserfs/xfs/jbd. However since I suppose a lot of disks flush everything pending on a flush cache command it still works assuming the file systems write the data to disk in fsync before syncing the journal. I don't know if they do that. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/