From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265353AbUBFSSc (ORCPT ); Fri, 6 Feb 2004 13:18:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265577AbUBFSSb (ORCPT ); Fri, 6 Feb 2004 13:18:31 -0500 Received: from e31.co.us.ibm.com ([32.97.110.129]:40400 "EHLO e31.co.us.ibm.com") by vger.kernel.org with ESMTP id S265353AbUBFSSa (ORCPT ); Fri, 6 Feb 2004 13:18:30 -0500 Message-Id: <200402061815.i16IFhY07073@owlet.beaverton.ibm.com> To: Anton Blanchard cc: piggin@cyberone.com.au, akpm@osdl.org, linux-kernel@vger.kernel.org, mjbligh@us.ibm.com, dvhltc@us.ibm.com Subject: Re: [PATCH] Load balancing problem in 2.6.2-mm1 In-reply-to: Your message of "Fri, 06 Feb 2004 21:30:10 +1100." <20040206103010.GI19011@krispykreme> Date: Fri, 06 Feb 2004 10:15:43 -0800 From: Rick Lindsley Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Good stuff, I just gave the patch a spin and things seem a little calmer. However Im still seeing a lot of balancing going on within a node. This is a clearly recognizable edge case, so I'll try drawing this up on some paper and see if I can suggest another patch. There's no good reason to move one lone process from a particular processor to another idle one. But it also approaches a question that's come up before: if you have 2 tasks on processor A and 1 on processor B, do you move one from A to B? One argument is that the two tasks on A will take twice as long as the one on B if you do nothing. But another says that bouncing a task around can't correct the overall imbalance and so is wasteful. I know of benchmarks where both behaviors are considered important. Thoughts? Rick