From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751720AbWDCVTb (ORCPT ); Mon, 3 Apr 2006 17:19:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751732AbWDCVTa (ORCPT ); Mon, 3 Apr 2006 17:19:30 -0400 Received: from smtp.osdl.org ([65.172.181.4]:2017 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751016AbWDCVTa (ORCPT ); Mon, 3 Apr 2006 17:19:30 -0400 Date: Mon, 3 Apr 2006 14:21:30 -0700 From: Andrew Morton To: Jens Axboe Cc: neilb@suse.de, nathans@sgi.com, linux-kernel@vger.kernel.org, drepper@redhat.com, mtk-manpages@gmx.net, nickpiggin@yahoo.com.au Subject: Re: [patch 1/1] sys_sync_file_range() Message-Id: <20060403142130.1868c0e3.akpm@osdl.org> In-Reply-To: <20060403143100.GH4647@suse.de> References: <200603300741.k2U7fQLe002202@shell0.pdx.osdl.net> <17451.36790.450410.79788@cse.unsw.edu.au> <20060331071736.K921158@wobbly.melbourne.sgi.com> <17456.31028.173800.615259@cse.unsw.edu.au> <20060403074959.GG3770@suse.de> <20060403012753.218db397.akpm@osdl.org> <20060403143100.GH4647@suse.de> X-Mailer: Sylpheed version 1.0.0 (GTK+ 1.2.10; i386-vine-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jens Axboe wrote: > > > > I don't think any disagrees with you, the sync-write process flag is > > > indeed an atrocious beast... > > > > Yeah. PF_SYNCWRITE was a performance tweak for the anticipatory scheduler. > > As cfq is using it as well now (hopefully to good effect) I guess it could > > be formalised more. > > Yup, both 'as' and 'cfq' would prefer to just look at a SYNC bio flag > instead. But the logic itself is definitely needed. hm. I actually thought we were already doing that. We should at least tranfer PF_SYNCWRITE into bi_flags at the point where we start to construct the BIO. That might well fix RAID, too. If it's handing work off to another thread via BIOs.