From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030362AbWD1I3i (ORCPT ); Fri, 28 Apr 2006 04:29:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030361AbWD1I3i (ORCPT ); Fri, 28 Apr 2006 04:29:38 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:33964 "EHLO fgwmail7.fujitsu.co.jp") by vger.kernel.org with ESMTP id S1030362AbWD1I3h (ORCPT ); Fri, 28 Apr 2006 04:29:37 -0400 Date: Fri, 28 Apr 2006 17:28:48 +0900 From: MAEDA Naoaki To: Kirill Korotaev Cc: efault@gmx.de, akpm@osdl.org, linux-kernel@vger.kernel.org, ckrm-tech@lists.sourceforge.net, maeda.naoaki@jp.fujitsu.com Subject: Re: [ckrm-tech] Re: [PATCH 0/9] CPU controller Message-Id: <20060428172848.df4baead.maeda.naoaki@jp.fujitsu.com> In-Reply-To: <4451AEA4.1040108@sw.ru> References: <20060428013730.9582.9351.sendpatchset@moscone.dvs.cs.fujitsu.co.jp> <1146201936.7523.15.camel@homer> <4451AEA4.1040108@sw.ru> Organization: FUJITSU LIMITED X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.3; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 28 Apr 2006 09:56:52 +0400 Kirill Korotaev wrote: > Also, as it turned out these doesn't do good fair scheduling under some > curcemstances (with busy loops on SMP) :(. Which was reported to MAEDA. Although it has buggy behaviour under some circumstances, the foundamental problem of load unfairness on SMP comes from the fact that a single task can not use more than one CPU at a time. On condtion that there aren't enough number of runnable tasks on SMP, achievable shares very depend on how tasks are allocated to CPU. So a few busy loops on SMP is a tough case. It is alleviated by increasing the number of runnable tasks. Thanks, MAEDA Naoaki