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