Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935616AbYBUWyb (ORCPT ); Thu, 21 Feb 2008 17:54:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756082AbYBUWyA (ORCPT ); Thu, 21 Feb 2008 17:54:00 -0500 Received: from el-out-1112.google.com ([209.85.162.181]:2466 "EHLO el-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935477AbYBUWx6 (ORCPT ); Thu, 21 Feb 2008 17:53:58 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=HZZMUJbs45Byu5rZSjx8m7//3BmmrmaYtu/55MGL51XYcj/Ldxlp7a70uNsP4bglRI6fR8G6x9N5LLHSxJTsoF4Yqqs7E0g4SCg56h7ua2a6rKU0mLgtJsyNmGs52m0Dxk8ctSKRgABsTPAHLFsI700bh94d4Da0S8th0idj6so= Message-ID: <9810cff90802211453l3f62200ey52edfeb9d84d7@mail.gmail.com> Date: Thu, 21 Feb 2008 14:53:56 -0800 From: "Bill Huey (hui)" To: "Ingo Molnar" Subject: Re: [PATCH [RT] 00/14] RFC - adaptive real-time locks Cc: "Gregory Haskins" , a.p.zijlstra@chello.nl, tglx@linutronix.de, rostedt@goodmis.org, linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, kevin@hilman.org, cminyard@mvista.com, dsingleton@mvista.com, dwalker@mvista.com, npiggin@suse.de, dsaxena@plexity.net, ak@suse.de, gregkh@suse.de, sdietrich@novell.com, pmorreale@novell.com, mkohari@novell.com In-Reply-To: <20080221214219.GA27209@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080221152504.4804.8724.stgit@novell1.haskins.net> <20080221212420.GA20953@elte.hu> <9810cff90802211333k3d19ca2exf28c18ae5a2b86a@mail.gmail.com> <20080221214219.GA27209@elte.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1119 Lines: 23 On Thu, Feb 21, 2008 at 1:42 PM, Ingo Molnar wrote: > I'd not exclude them fundamentally though, it's really the numbers that > matter. The code is certainly simple enough (albeit the .config and > sysctl controls are quite ugly and unacceptable - adaptive mutexes > should really be ... adaptive, with no magic constants in .configs or > else). > > But ... i'm somewhat sceptic, after having played with spin-a-bit > mutexes before. Yeah, it's yet another reason to get better instrumentation in -rt for this purpose and why it's important to only log things in the slow path so that the front end of the rtmutex doesn't see instrumentation artifacts in the measurement. If I get a chance tonight, I'll extend lockdep/lockstat for this purpose if peterz doesn't beat me to it. I won't have access to the test harness to replicate this though. 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/