From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753931Ab1C2QpN (ORCPT ); Tue, 29 Mar 2011 12:45:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:22129 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750991Ab1C2QpL (ORCPT ); Tue, 29 Mar 2011 12:45:11 -0400 Date: Tue, 29 Mar 2011 12:44:45 -0400 From: Vivek Goyal To: Lina Lu Cc: linux kernel mailing list Subject: Re: Blkio: Apply two policies on one IO process Message-ID: <20110329164445.GB24485@redhat.com> References: <201103300000153595438@foxmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201103300000153595438@foxmail.com> 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 Wed, Mar 30, 2011 at 12:00:16AM +0800, Lina Lu wrote: > Hi Vivek, > As the weight and throttle policies are on different layers, someone can apply > these two policies on one IO pid at one time. And the IO bandwidth will be controlled > with the more stringent policy. > If someone first set two policies on one pid, then want to remove the weight > policy, he must first echo the pid to parent dir's tasks, then echo the throttle policy > to parent dir's blkio.throttle_xx_xx_device. These steps seen to be cumbersome. > This is because the weight policy can be applied independence, but the throttle > policy is always accompany with the weight policy(default 500). I think it will be > better that these policies are independent of each other. What is your opinion? > Additional, do you recommend applying two policies on one IO process? How do you want to make these independent? - If one does not want weight based policy, one can change IO scheduler to deadline. - If one does not want throttling policy, do not apply throttling limits. Thanks Vivek