From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vivek Goyal Subject: Re: [Lsf] IO less throttling and cgroup aware writeback (Was: Re: Preliminary Agenda and Activities for LSF) Date: Thu, 21 Apr 2011 11:07:20 -0400 Message-ID: <20110421150720.GD8192@redhat.com> References: <20110330153757.GD1291@redhat.com> <20110330222002.GB20849@dastard> <20110331141637.GA11139@redhat.com> <1301581251-sup-987@think> <20110331221425.GB2904@dastard> <20110401013424.GA17928@redhat.com> <20110401043605.GA6957@dastard> <20110401063254.GA28242@infradead.org> <20110401072348.GD6957@dastard> <20110401125654.GA20003@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dave Chinner , James Bottomley , lsf , linux-fsdevel , Jens Axboe To: Christoph Hellwig Return-path: Received: from mx1.redhat.com ([209.132.183.28]:23897 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754425Ab1DUPIF (ORCPT ); Thu, 21 Apr 2011 11:08:05 -0400 Content-Disposition: inline In-Reply-To: <20110401125654.GA20003@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, Apr 01, 2011 at 08:56:54AM -0400, Christoph Hellwig wrote: > On Fri, Apr 01, 2011 at 06:23:48PM +1100, Dave Chinner wrote: > > Oh, I misread the code in _xfs_buf_read that fiddles with > > _XBF_RUN_QUEUES. That flag is dead then, as is the XBF_LOG_BUFFER > > code which appears to have been superceded by the new XBF_ORDERED > > code. Definitely needs cleaning up. > > Yes, that's been on my todo list for a while, but I first want a sane > defintion of REQ_META in the block layer. Will splitting REQ_META in two will help. Say REQ_META_SYNC and REQ_META_ASYNC. So meta requests which don't require any kind of priority boost at CFQ can mark these REQ_META_ASYNC (XFS). - So we retain the capability to mark metadata requests - Priority boost only for selected meta data. - Throttling can use this to avoid throttling meta data. Thanks Vivek