From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756857AbXK0LR2 (ORCPT ); Tue, 27 Nov 2007 06:17:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753693AbXK0LRV (ORCPT ); Tue, 27 Nov 2007 06:17:21 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:35050 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753588AbXK0LRU (ORCPT ); Tue, 27 Nov 2007 06:17:20 -0500 Date: Tue, 27 Nov 2007 12:17:07 +0100 From: Ingo Molnar To: "Zhang, Yanmin" Cc: LKML Subject: Re: sched_yield: delete sysctl_sched_compat_yield Message-ID: <20071127111707.GA18727@elte.hu> References: <1196155985.25646.31.camel@ymzhang> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1196155985.25646.31.camel@ymzhang> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.1 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.1 required=5.9 tests=BAYES_05 autolearn=no SpamAssassin version=3.2.3 -1.1 BAYES_05 BODY: Bayesian spam probability is 1 to 5% [score: 0.0357] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Zhang, Yanmin wrote: > If echo "1">/proc/sys/kernel/sched_compat_yield before starting > volanoMark testing, the result is very good with kernel 2.6.24-rc3 on > my 16-core tigerton. yep, that's known and has been discussed in detail on lkml. Java should use something more suitable than sched_yield for its locking. Yield will always be dependent on scheduling details and _some_ category of apps will always hurt. That's why we offer the sched_compat_yield flag. Ingo