From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752196AbbFZNzz (ORCPT ); Fri, 26 Jun 2015 09:55:55 -0400 Received: from mail-yk0-f180.google.com ([209.85.160.180]:35899 "EHLO mail-yk0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752048AbbFZNzr (ORCPT ); Fri, 26 Jun 2015 09:55:47 -0400 Date: Fri, 26 Jun 2015 09:55:44 -0400 From: Tejun Heo To: Vivek Goyal Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, avanzini.arianna@gmail.com, kernel-team@fb.com Subject: Re: [PATCH 2/6] blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it Message-ID: <20150626135544.GC15805@mtj.duckdns.org> References: <1435268337-1738-1-git-send-email-tj@kernel.org> <1435268337-1738-3-git-send-email-tj@kernel.org> <20150626132702.GA14803@redhat.com> <20150626133540.GA15805@mtj.duckdns.org> <20150626134525.GB14803@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150626134525.GB14803@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 26, 2015 at 09:45:25AM -0400, Vivek Goyal wrote: > I was just curious that why aux_cnt is different from rest of the stats. > (It is atomic64_t while others are not). Ooh because otherwise we'd have to protect it with sth - a spinlock, u64 stat sync thing or whatever. It's just a lot simpler and more robust to use atomics. Thanks. -- tejun