From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753873Ab1HIQRA (ORCPT ); Tue, 9 Aug 2011 12:17:00 -0400 Received: from merlin.infradead.org ([205.233.59.134]:39168 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753284Ab1HIQQ7 convert rfc822-to-8bit (ORCPT ); Tue, 9 Aug 2011 12:16:59 -0400 Subject: Re: [PATCH 3/5] writeback: dirty rate control From: Peter Zijlstra To: Vivek Goyal Cc: Wu Fengguang , linux-fsdevel@vger.kernel.org, Andrew Morton , Jan Kara , Christoph Hellwig , Dave Chinner , Greg Thelen , Minchan Kim , Andrea Righi , linux-mm , LKML Date: Tue, 09 Aug 2011 18:16:30 +0200 In-Reply-To: <20110809155046.GD6482@redhat.com> References: <20110806084447.388624428@intel.com> <20110806094526.878435971@intel.com> <20110809155046.GD6482@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.0.2- Message-ID: <1312906591.1083.43.camel@twins> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2011-08-09 at 11:50 -0400, Vivek Goyal wrote: > > So IIUC, bdi->dirty_ratelimit is the dynmically adjusted desired rate > limit (based on postion ratio, dirty_bw and write_bw). But this seems > to be overall bdi limit and does not seem to take into account the > number of tasks doing IO to that bdi (as your comment suggests). So > it probably will track write_bw as opposed to write_bw/N. What am > I missing? I think the per task thing comes from him using the pages_dirtied argument to balance_dirty_pages() to compute the sleep time. Although I'm not quite sure how he keeps fairness in light of the sleep time bounding to MAX_PAUSE. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH 3/5] writeback: dirty rate control Date: Tue, 09 Aug 2011 18:16:30 +0200 Message-ID: <1312906591.1083.43.camel@twins> References: <20110806084447.388624428@intel.com> <20110806094526.878435971@intel.com> <20110809155046.GD6482@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Cc: Wu Fengguang , linux-fsdevel@vger.kernel.org, Andrew Morton , Jan Kara , Christoph Hellwig , Dave Chinner , Greg Thelen , Minchan Kim , Andrea Righi , linux-mm , LKML To: Vivek Goyal Return-path: In-Reply-To: <20110809155046.GD6482@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Tue, 2011-08-09 at 11:50 -0400, Vivek Goyal wrote: >=20 > So IIUC, bdi->dirty_ratelimit is the dynmically adjusted desired rate > limit (based on postion ratio, dirty_bw and write_bw). But this seems > to be overall bdi limit and does not seem to take into account the > number of tasks doing IO to that bdi (as your comment suggests). So > it probably will track write_bw as opposed to write_bw/N. What am > I missing?=20 I think the per task thing comes from him using the pages_dirtied argument to balance_dirty_pages() to compute the sleep time. Although I'm not quite sure how he keeps fairness in light of the sleep time bounding to MAX_PAUSE. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta7.messagelabs.com (mail6.bemta7.messagelabs.com [216.82.255.55]) by kanga.kvack.org (Postfix) with ESMTP id 0ADEA6B0169 for ; Tue, 9 Aug 2011 12:16:59 -0400 (EDT) Subject: Re: [PATCH 3/5] writeback: dirty rate control From: Peter Zijlstra Date: Tue, 09 Aug 2011 18:16:30 +0200 In-Reply-To: <20110809155046.GD6482@redhat.com> References: <20110806084447.388624428@intel.com> <20110806094526.878435971@intel.com> <20110809155046.GD6482@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID: <1312906591.1083.43.camel@twins> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Vivek Goyal Cc: Wu Fengguang , linux-fsdevel@vger.kernel.org, Andrew Morton , Jan Kara , Christoph Hellwig , Dave Chinner , Greg Thelen , Minchan Kim , Andrea Righi , linux-mm , LKML On Tue, 2011-08-09 at 11:50 -0400, Vivek Goyal wrote: >=20 > So IIUC, bdi->dirty_ratelimit is the dynmically adjusted desired rate > limit (based on postion ratio, dirty_bw and write_bw). But this seems > to be overall bdi limit and does not seem to take into account the > number of tasks doing IO to that bdi (as your comment suggests). So > it probably will track write_bw as opposed to write_bw/N. What am > I missing?=20 I think the per task thing comes from him using the pages_dirtied argument to balance_dirty_pages() to compute the sleep time. Although I'm not quite sure how he keeps fairness in light of the sleep time bounding to MAX_PAUSE. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org