From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757111AbXGIP7u (ORCPT ); Mon, 9 Jul 2007 11:59:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753749AbXGIP7n (ORCPT ); Mon, 9 Jul 2007 11:59:43 -0400 Received: from smtp-out.google.com ([216.239.45.13]:45095 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753960AbXGIP7m (ORCPT ); Mon, 9 Jul 2007 11:59:42 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:message-id:date:from:user-agent:mime-version:to:cc: subject:references:in-reply-to:content-type:content-transfer-encoding; b=S44POKubqNYSif4bY5rXgi76Jb+eG7Ew4Ti12lIkr1NUh+Kvlen/BgM20L4buOHbV tCoiwqeBjGoqXzdLlk1Pw== Message-ID: <46925B5D.8000507@google.com> Date: Mon, 09 Jul 2007 08:59:25 -0700 From: Martin Bligh User-Agent: Thunderbird 1.5.0.12 (X11/20070604) MIME-Version: 1.0 To: Christoph Lameter CC: Andi Kleen , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [patch 00/10] [RFC] SLUB patches for more functionality, performance and maintenance References: <20070708034952.022985379@sgi.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christoph Lameter wrote: > On Sun, 8 Jul 2007, Andi Kleen wrote: > >> Christoph Lameter writes: >> >>> A cmpxchg is less costly than interrupt enabe/disable >> That sounds wrong. > > Martin Bligh was able to significantly increase his LTTng performance > by using cmpxchg. See his article in the 2007 proceedings of the OLS > Volume 1, page 39. > > His numbers were: > > interrupts enable disable : 210.6ns > local cmpxchg : 9.0ns Those numbers came from Mathieu Desnoyers (LTTng) if you want more details.