Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S280502AbUKBDSn (ORCPT ); Mon, 1 Nov 2004 22:18:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262162AbUKBDMr (ORCPT ); Mon, 1 Nov 2004 22:12:47 -0500 Received: from smtp.Lynuxworks.com ([207.21.185.24]:55044 "EHLO smtp.lynuxworks.com") by vger.kernel.org with ESMTP id S287685AbUKAW73 (ORCPT ); Mon, 1 Nov 2004 17:59:29 -0500 Date: Mon, 1 Nov 2004 14:59:06 -0800 To: Florian Schmidt Cc: Bill Huey , Ingo Molnar , Thomas Gleixner , Lee Revell , Paul Davis , LKML , mark_h_johnson@raytheon.com, Adam Heath , Michal Schmidt , Fernando Pablo Lopez-Lezcano , Karsten Wiese , Rui Nuno Capela , "K.R. Foley" Subject: Re: [Fwd: Re: [patch] Real-Time Preemption, -RT-2.6.9-mm1-V0.4] Message-ID: <20041101225906.GA19276@nietzsche.lynx.com> References: <20041031165913.2d0ad21e@mango.fruits.de> <20041031200621.212ee044@mango.fruits.de> <20041101134235.GA18009@elte.hu> <20041101135358.GA19718@elte.hu> <20041101140630.GA20448@elte.hu> <1099324040.3337.32.camel@thomas> <20041101184615.GB32009@elte.hu> <20041101233037.314337c8@mango.fruits.de> <20041101224047.GA19186@nietzsche.lynx.com> <20041101235125.2ae638a4@mango.fruits.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041101235125.2ae638a4@mango.fruits.de> User-Agent: Mutt/1.5.6+20040907i From: Bill Huey (hui) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1193 Lines: 23 On Mon, Nov 01, 2004 at 11:51:25PM +0100, Florian Schmidt wrote: [...lock debugging...] > ack. understood. i was just asking since i don't have a second machine and > thus am not really able to help with the deadlock debugging. so i figured i > could at least do some timing. btw: even with deadlock detection, the > results for 0.6.5 looked pretty good [in 10 minutes uptime ca.3-4% max > jitter [30something usecs]. until the deadlock that is [i head three finds > plus kernel compile at nice -10 running].. The lock chains aren't that deep in Linux so the algorithmic complexity is not going to hit some crazy polynomial time unless there's some seriously nasty contention at a certain point in the kernel (billions of readers for example against a write aquire). But when we start to see things like that under pressure is when we need to start shortening the need for that/those lock(s) for that/those critical section(s) in question. bill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/