From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [Lsf] Preliminary Agenda and Activities for LSF Date: Wed, 30 Mar 2011 15:18:02 +1100 Message-ID: <20110330041802.GA20849@dastard> References: <1301373398.2590.20.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: James Bottomley , lsf@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, Curt Wohlgemuth To: Chad Talbott Return-path: Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:23024 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750972Ab1C3ESH (ORCPT ); Wed, 30 Mar 2011 00:18:07 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Mar 29, 2011 at 10:35:13AM -0700, Chad Talbott wrote: > I'd like to propose a discussion topic: > > IO-less Dirty Throttling Considered Harmful... > > to isolation and cgroup IO schedulers in general. Why is that, exactly? The current writeback infrastructure isn't cgroup aware at all, so isn't that the problem you need to solve first? i.e. how to delegate page cache writeback from one context to anotheri and account for it correctly? Once you solve that problem, triggering cgroup specific writeback from the throttling code is the same regardless of whether we are doing IO directly from the throttling code or via a separate flusher thread. Hence I don't really understand why you think IO-less throttling is really a problem. Cheers, Dave. -- Dave Chinner david@fromorbit.com