From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754762AbYAVOtw (ORCPT ); Tue, 22 Jan 2008 09:49:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751141AbYAVOtp (ORCPT ); Tue, 22 Jan 2008 09:49:45 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:55902 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750985AbYAVOto (ORCPT ); Tue, 22 Jan 2008 09:49:44 -0500 Subject: Re: [PATCH 0/6] IO context sharing From: Peter Zijlstra To: Jens Axboe Cc: linux-kernel@vger.kernel.org, knikanth@novell.com In-Reply-To: <1200995361-24001-1-git-send-email-jens.axboe@oracle.com> References: <1200995361-24001-1-git-send-email-jens.axboe@oracle.com> Content-Type: text/plain Date: Tue, 22 Jan 2008 15:49:31 +0100 Message-Id: <1201013372.6341.19.camel@lappy> Mime-Version: 1.0 X-Mailer: Evolution 2.21.5 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-01-22 at 10:49 +0100, Jens Axboe wrote: > Hi, > > Today io contexts are per-process and define the (surprise) io context > of that process. In some situations it would be handy if several > processes share an IO context. With syslets it's especially crucial that > the threads working on behalf of the parent process are seen as the same > IO context. That goes from both a fairness and performance point of > view, since IO schedulers like AS and CFQ base decisions on what the > IO context state is. This patchset adds support for processes sharing a > single io context and also adds a CLONE_IO flag to denote sharing of > IO context. Are you planning on extending this to a hierarchical CFQ for cgroups, or just giving the IO context to a cgroup?