From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753804Ab2AWSwA (ORCPT ); Mon, 23 Jan 2012 13:52:00 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:47760 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753641Ab2AWSv6 (ORCPT ); Mon, 23 Jan 2012 13:51:58 -0500 Date: Mon, 23 Jan 2012 10:51:53 -0800 From: Tejun Heo To: Vivek Goyal Cc: axboe@kernel.dk, ctalbott@google.com, rni@google.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 08/17] blkcg: shoot down blkio_groups on elevator switch Message-ID: <20120123185153.GJ12652@google.com> References: <1327202725-3383-9-git-send-email-tj@kernel.org> <20120123152055.GD25986@redhat.com> <20120123153913.GB12652@google.com> <20120123155216.GF25986@redhat.com> <20120123155745.GD12652@google.com> <20120123161042.GG25986@redhat.com> <20120123161619.GE12652@google.com> <20120123162553.GI25986@redhat.com> <20120123171049.GH12652@google.com> <20120123183207.GL25986@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120123183207.GL25986@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 On Mon, Jan 23, 2012 at 01:32:07PM -0500, Vivek Goyal wrote: > This is not just specific to blk-throttle. If in future throttling policy > is removable like elevator, then it will be fine to reset the throttling > related configuration upon removal of throttling policy. But resetting > throttling configuration without policy going anywhere does not sound good. Yeah, that is a compromise. As long as those configurations are per-queue, which is the way it's gonna be after the clean up, I don't think it's a big deal tho. We'll be saying "if you make changes to the set of blkcg policies applied to a device, all blkcg configurations regarding the device will be reset" instead of "if any change to blkcg policies happen system-wide, all blkcg configurations will be reset", and the former doesn't sound crazy to me. Anyways, let's see how complex doing the finer grained thing gets. -- tejun