From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758097Ab2JSTgH (ORCPT ); Fri, 19 Oct 2012 15:36:07 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:44394 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757544Ab2JSTgE (ORCPT ); Fri, 19 Oct 2012 15:36:04 -0400 Date: Fri, 19 Oct 2012 12:36:00 -0700 From: Tejun Heo To: Vivek Goyal Cc: Robin Dong , linux-kernel@vger.kernel.org, Robin Dong , Jens Axboe , Tao Ma Subject: Re: [PATCH V3] block/throttle: Add IO throttled information in blkio.throttle Message-ID: <20121019193600.GK13370@google.com> References: <1349765625-4020-1-git-send-email-robin.k.dong@gmail.com> <20121016232706.GI16166@google.com> <20121017134945.GC31663@redhat.com> <20121018232404.GW13370@google.com> <20121019150011.GE27052@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121019150011.GE27052@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Vivek. On Fri, Oct 19, 2012 at 11:00:11AM -0400, Vivek Goyal wrote: > > That way we can stick to the usual stats facility. > > So how does this help? Because it is a monotonically increasing value > we can use per cpu stats without extra locking? Or somthing else? It's generally much simpler to expose dumb increasing counters. You don't have to worry about mismatching decrements (for whatever reason, percpu or segmented counters), so unless there's a pretty good reason to deviate, why deviate? Thanks. -- tejun