Received: with ECARTIS (v1.0.0; list linux-xfs); Thu, 27 Nov 2003 14:19:25 -0800 (PST) Received: from mail.osdl.org (fw.osdl.org [65.172.181.6]) by oss.sgi.com (8.12.10/8.12.9) with SMTP id hARMJ4Ta012088 for ; Thu, 27 Nov 2003 14:19:04 -0800 Received: from mnm (build.pdx.osdl.net [172.20.1.2]) by mail.osdl.org (8.11.6/8.11.6) with ESMTP id hARMIrC11145; Thu, 27 Nov 2003 14:18:53 -0800 Date: Thu, 27 Nov 2003 14:25:55 -0800 From: Andrew Morton To: Nathan Scott Cc: beto@kasenna.com, linux-xfs@oss.sgi.com Subject: Re: direct-IO writes strange behavior Message-Id: <20031127142555.3e0142c5.akpm@osdl.org> In-Reply-To: <20031127211827.GB708@frodo> References: <3FBECF7E.6010509@kasenna.com> <3FBFEF6A.3000609@kasenna.com> <20031127004420.77f31a9c.akpm@osdl.org> <20031127211827.GB708@frodo> X-Mailer: Sylpheed version 0.9.4 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-archive-position: 1145 X-ecartis-version: Ecartis v1.0.0 Sender: linux-xfs-bounce@oss.sgi.com Errors-to: linux-xfs-bounce@oss.sgi.com X-original-sender: akpm@osdl.org Precedence: bulk X-list: linux-xfs Content-Length: 779 Lines: 23 Nathan Scott wrote: > > hi Andrew, > > On Thu, Nov 27, 2003 at 12:44:20AM -0800, Andrew Morton wrote: > > Alberto Nava wrote: > > > > > > I've done some more digging on this issue. The reason the > > > request is going in 4k pages is that the direct-io code is > > > giving up in do_direct_IO() and the request is issued as buffer IO :-(. > > > > You seem to be using a -mm kernel. It has extensive and not-quite-complete > > and not-really-tested-at-all-with-XFS direct-io changes. > > > Alberto's original mail said: > > > I'm seeing a very strange behavior when I write to a file using 512k > > direct-io writes. The filesystem is XFS and the kernel is 2.6.0-test9. > I know. But the code which he quoted had -mm stuff in it.