From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756867Ab3AHSIN (ORCPT ); Tue, 8 Jan 2013 13:08:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33486 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756765Ab3AHSIL (ORCPT ); Tue, 8 Jan 2013 13:08:11 -0500 Date: Tue, 8 Jan 2013 13:08:04 -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 21/24] blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock Message-ID: <20130108180804.GC29933@redhat.com> References: <1356726946-26037-1-git-send-email-tj@kernel.org> <1356726946-26037-22-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1356726946-26037-22-git-send-email-tj@kernel.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 Fri, Dec 28, 2012 at 12:35:43PM -0800, Tejun Heo wrote: > Instead of holding blkcg->lock while walking ->blkg_list and executing > prfill(), RCU walk ->blkg_list and hold the blkg's queue lock while > executing prfill(). This makes prfill() implementations easier as > stats are mostly protected by queue lock. > > This will be used to implement hierarchical stats. > > Signed-off-by: Tejun Heo Acked-by: Vivek Goyal Vivek