From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753577Ab2LQVSw (ORCPT ); Mon, 17 Dec 2012 16:18:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:7024 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752559Ab2LQVSu (ORCPT ); Mon, 17 Dec 2012 16:18:50 -0500 Date: Mon, 17 Dec 2012 16:18:43 -0500 From: Vivek Goyal To: Tejun Heo Cc: lizefan@huawei.com, axboe@kernel.dk, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, ctalbott@google.com, rni@google.com Subject: Re: [PATCH 06/12] cfq-iosched: implement cfq_group->nr_active and ->level_weight Message-ID: <20121217211843.GA13691@redhat.com> References: <1355524885-22719-1-git-send-email-tj@kernel.org> <1355524885-22719-7-git-send-email-tj@kernel.org> <20121217204609.GH7235@redhat.com> <20121217211517.GC1844@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121217211517.GC1844@htj.dyndns.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 17, 2012 at 01:15:17PM -0800, Tejun Heo wrote: > Hello, Vivek. > > On Mon, Dec 17, 2012 at 03:46:09PM -0500, Vivek Goyal wrote: > > On Fri, Dec 14, 2012 at 02:41:19PM -0800, Tejun Heo wrote: > > > To prepare for blkcg hierarchy support, add cfqg->nr_active and > > > ->level_weight. cfqg->nr_active counts the number of active cfqgs at > > > the cfqg's level and ->level_weight is sum of weights of those cfqgs. > > > The level covers itself (cfqg->leaf_weight) and immediate children. > > > > This notion of level is really confusing. If one says "at cfqg's level" > > I immediately associate with cfqg's siblings and not with cfqg's children. > > We can explicitly say at children's level but I think it should be > enough to explain it clearly in the comment where the field is > defined. > > > I think confusion happens because we are overloading the definition of > > cfqg. It is competing with its siblings at the same time it is competing > > against its child groups (on behalf of its children tasks). > > While I agree that part is a bit tricky, I can't think of a much > better way to describe it. Any better ideas? Can we call it cfqg->children_weight insted of cfqg->level_weight. Thanks Vivek