From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756612AbYE0RTe (ORCPT ); Tue, 27 May 2008 13:19:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752195AbYE0RT0 (ORCPT ); Tue, 27 May 2008 13:19:26 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:55681 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799AbYE0RTZ (ORCPT ); Tue, 27 May 2008 13:19:25 -0400 Date: Tue, 27 May 2008 22:58:07 +0530 From: Srivatsa Vaddagiri To: "Chris Friesen" Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, a.p.zijlstra@chello.nl, pj@sgi.com, dhaval@linux.vnet.ibm.com, Balbir Singh , aneesh.kumar@linux.vnet.ibm.com Subject: Re: fair group scheduler not so fair? Message-ID: <20080527172807.GF30285@linux.vnet.ibm.com> Reply-To: vatsa@linux.vnet.ibm.com References: <4834B75A.40900@nortel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4834B75A.40900@nortel.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 21, 2008 at 05:59:22PM -0600, Chris Friesen wrote: > I then redid the test with two hogs in one group and three hogs in the > other group. Unfortunately, the cpu shares were not equally distributed > within each group. Using a 10-sec interval in "top", I got the following: I ran with this combination (2 in Group a and 3 in Group b) on top of the experimental patch I sent and here's what I get: 4350 root 20 0 1384 228 176 R 53.8 0.0 52:27.54 1 hoga 4542 root 20 0 1384 228 176 R 49.3 0.0 3:39.76 0 hoga 4352 root 20 0 1384 232 176 R 36.0 0.0 26:53.50 1 hogb 4351 root 20 0 1384 228 176 R 32.0 0.0 26:47.54 0 hogb 4543 root 20 0 1384 232 176 R 29.0 0.0 2:03.62 0 hogb Note that fairness (using load balance approach we have currently) works over a long window. Usually I observe with "top -d30". Higher the asymmetry of task-load distribution, longer it takes to converge to fairness. -- Regards, vatsa