Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756829AbZFWCVS (ORCPT ); Mon, 22 Jun 2009 22:21:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752423AbZFWCVF (ORCPT ); Mon, 22 Jun 2009 22:21:05 -0400 Received: from mx2.redhat.com ([66.187.237.31]:52579 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752335AbZFWCVE (ORCPT ); Mon, 22 Jun 2009 22:21:04 -0400 From: Jeff Moyer To: Vivek Goyal Cc: Balbir Singh , linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, dm-devel@redhat.com, jens.axboe@oracle.com, nauman@google.com, dpshah@google.com, lizf@cn.fujitsu.com, mikew@google.com, fchecconi@gmail.com, paolo.valente@unimore.it, ryov@valinux.co.jp, fernando@oss.ntt.co.jp, s-uchida@ap.jp.nec.com, taka@valinux.co.jp, guijianfeng@cn.fujitsu.com, dhaval@linux.vnet.ibm.com, righi.andrea@gmail.com, m-ikeda@ds.jp.nec.com, jbaron@redhat.com, agk@redhat.com, snitzer@redhat.com, akpm@linux-foundation.org, peterz@infradead.org Subject: Re: [PATCH 02/20] io-controller: Common flat fair queuing code in elevaotor layer References: <1245443858-8487-1-git-send-email-vgoyal@redhat.com> <1245443858-8487-3-git-send-email-vgoyal@redhat.com> <20090622084612.GD3728@balbir.in.ibm.com> <20090623020515.GA3620@redhat.com> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Mon, 22 Jun 2009 22:20:24 -0400 In-Reply-To: <20090623020515.GA3620@redhat.com> (Vivek Goyal's message of "Mon, 22 Jun 2009 22:05:15 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1681 Lines: 52 Vivek Goyal writes: > On Mon, Jun 22, 2009 at 02:16:12PM +0530, Balbir Singh wrote: >> > + ioq->pid = current->pid; >> >> Is pid used for cgroup association later? I don't see why we save the >> pid otherwise? If yes, why not store the cgroup of the current->pid? >> > > This is just for logging purposes (blktrace), useful for CFQ where every task > context sets up one queue and this number becomes the identifier for the queue. > Look at elv_log_ioq(), which uses ioq->pid. Well, that's not 100% accurate as tasks can share I/O contexts. However, the 1:1 mapping does hold true most of the time. > [..] >> > + * coop tells that io scheduler selected a queue for us and we did not >> >> coop? > > coop refers to "cooperating". I guess "coop" is not descriptive. I will > change the name to "cooperating" and also put more description for > clarity. I think just more description is fine. I'm not sure you need to spell out cooperating (that will make for some long lines!). >> > + struct io_queue *async_idle_queue; >> > + >> > + /* >> > + * Used to track any pending rt requests so we can pre-empt current >> > + * non-RT cfqq in service when this value is non-zero. >> > + */ >> > + unsigned int busy_rt_queues; >> > +}; >> > + >> > +struct elv_fq_data { >> >> What does fq stand for? > > Fair queuing. Any suggestions to make it better? I think you could just put it in the comment. Cheers, Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/