From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262322AbTD3S6T (ORCPT ); Wed, 30 Apr 2003 14:58:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262326AbTD3S6T (ORCPT ); Wed, 30 Apr 2003 14:58:19 -0400 Received: from [12.47.58.20] ([12.47.58.20]:50751 "EHLO pao-ex01.pao.digeo.com") by vger.kernel.org with ESMTP id S262322AbTD3S6F (ORCPT ); Wed, 30 Apr 2003 14:58:05 -0400 Date: Wed, 30 Apr 2003 12:11:05 -0700 From: Andrew Morton To: Maciej Soltysiak Cc: linux-kernel@vger.kernel.org Subject: Re: must-fix list for 2.6.0 Message-Id: <20030430121105.454daee1.akpm@digeo.com> In-Reply-To: References: <20030429155731.07811707.akpm@digeo.com> X-Mailer: Sylpheed version 0.8.11 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 30 Apr 2003 19:10:19.0169 (UTC) FILETIME=[23F4E910:01C30F4C] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Maciej Soltysiak wrote: > > > kernel/ > > ------- > > > > - O(1) scheduler starvation, poor behaviour seems unresolved. > > > > Jens: "I've been running 2.5.67-mm3 on my workstation for two days, and > > it still doesn't feel as good as 2.4. It's not a disaster like some > > revisisons ago, but it still has occasional CPU "stalls" where it feels > > like a process waits for half a second of so for CPU time. That's is very > > noticable." > Well, i had similar problems with 2.5 stalling, but now that i disabled > preemtible kernel, it is better now. Are there no complaints about preemt? I have not heard of any, apart from yours. > Also there is one issue, i am not sure if this may be a kernel issue, > but with setiathome running in a X desktop environment all apps work fine, > but when i run openoffice, openoffice responds with 5 second delay. That'll be the changed sched_yield() semantics. The below patch should fix that up, but we need to decide whether the (rather unclear) advantages of the sched_yield() change outweigh the breakage which it caused linuxthreads applications. diff -puN kernel/sched.c~sched_yield-hack kernel/sched.c --- 25/kernel/sched.c~sched_yield-hack 2003-04-30 12:08:51.000000000 -0700 +++ 25-akpm/kernel/sched.c 2003-04-30 12:09:11.000000000 -0700 @@ -1992,7 +1992,7 @@ asmlinkage long sys_sched_yield(void) */ if (likely(!rt_task(current))) { dequeue_task(current, array); - enqueue_task(current, rq->expired); + enqueue_task(current, array); } else { list_del(¤t->run_list); list_add_tail(¤t->run_list, array->queue + current->prio); _