From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271807AbTG2OH0 (ORCPT ); Tue, 29 Jul 2003 10:07:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271816AbTG2OH0 (ORCPT ); Tue, 29 Jul 2003 10:07:26 -0400 Received: from e35.co.us.ibm.com ([32.97.110.133]:53934 "EHLO e35.co.us.ibm.com") by vger.kernel.org with ESMTP id S271807AbTG2OHR (ORCPT ); Tue, 29 Jul 2003 10:07:17 -0400 Subject: Re: [Lse-tech] Re: [patch] scheduler fix for 1cpu/node case To: Erich Focht , "Martin J. Bligh" , linux-kernel , LSE Cc: Andi Kleen , torvalds@osdl.org X-Mailer: Lotus Notes Release 5.0.7 March 21, 2001 Message-ID: From: Mala Anand Date: Tue, 29 Jul 2003 09:06:14 -0500 X-MIMETrack: Serialize by Router on D03NM123/03/M/IBM(Release 6.0.1 [IBM]|June 10, 2003) at 07/29/2003 08:06:15 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >> If you want data supporting my assumptions: Ted Ts'o's talk at OLS >> shows the necessity to rebalance ASAP (even in try_to_wake_up). >If this is the patch I am thinking of, it was the (attached) one I sent them, >which did a light "push" rebalance at try_to_wake_up. Calling load_balance >at try_to_wake_up seems very heavy-weight. This patch only looks for an idle >cpu (within the same node) to wake up on before task activation, only if the >task_rq(p)->nr_running is too long. So, yes, I do believe this can be >important, but I think it's only called for when we have an idle cpu. The patch that you sent to Rajan didn't yield any improvement on specjappserver so we did not include that in the ols paper. What is described in the ols paper is "calling load-balance" from try-to-wake-up. Both calling load-balance from try-to-wakeup and the "light push" rebalance at try_to_wake_up are already done in Andrea's 0(1) scheduler patch. Regards, Mala Mala Anand IBM Linux Technology Center - Kernel Performance E-mail:manand@us.ibm.com http://www-124.ibm.com/developerworks/opensource/linuxperf http://www-124.ibm.com/developerworks/projects/linuxperf Phone:838-8088; Tie-line:678-8088