From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262496AbVG2L2X (ORCPT ); Fri, 29 Jul 2005 07:28:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262535AbVG2L2X (ORCPT ); Fri, 29 Jul 2005 07:28:23 -0400 Received: from mx1.elte.hu ([157.181.1.137]:41690 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S262513AbVG2L0z (ORCPT ); Fri, 29 Jul 2005 07:26:55 -0400 Date: Fri, 29 Jul 2005 13:26:16 +0200 From: Ingo Molnar To: "Chen, Kenneth W" Cc: "'Nick Piggin'" , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org Subject: Re: Delete scheduler SD_WAKE_AFFINE and SD_WAKE_BALANCE flags Message-ID: <20050729112616.GA24965@elte.hu> References: <200507282308.j6SN8Tg01993@unix-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200507282308.j6SN8Tg01993@unix-os.sc.intel.com> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Chen, Kenneth W wrote: > To demonstrate the problem, we turned off these two flags in the cpu > sd domain and measured a stunning 2.15% performance gain! And > deleting all the code in the try_to_wake_up() pertain to load > balancing gives us another 0.2% gain. another thing: do you have a HT-capable ia64 CPU, and do you have CONFIG_SCHED_SMT turned on? If yes then could you try to turn off SD_WAKE_IDLE too, i found it to bring further performance improvements in certain workloads. Ingo