From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752660Ab1GUXeo (ORCPT ); Thu, 21 Jul 2011 19:34:44 -0400 Received: from claw.goop.org ([74.207.240.146]:37514 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751941Ab1GUXem (ORCPT ); Thu, 21 Jul 2011 19:34:42 -0400 Message-ID: <4E28B749.10304@goop.org> Date: Thu, 21 Jul 2011 16:33:29 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.18) Gecko/20110621 Fedora/3.1.11-1.fc15 Lightning/1.0b3pre Thunderbird/3.1.11 MIME-Version: 1.0 To: Andi Kleen CC: Peter Zijlstra , "H. Peter Anvin" , Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List , Nick Piggin , Jeremy Fitzhardinge Subject: Re: [PATCH RFC 0/7] x86: convert ticketlocks to C and remove duplicate code References: In-Reply-To: X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/29/2011 01:44 PM, Andi Kleen wrote: > Jeremy Fitzhardinge writes: >> I couldn't measure a consistent performance difference between the two >> implemenations; there seemed to be +/- ~1% +/-, which is the level of >> variation I see from simply recompiling the kernel with slightly >> different code alignment. > I ran your new locks in my lock tester and I have a similar experience. > There's some variation, but it seems to be in the usual variance. > In some cases the C locks were actually faster. Yes, I observed cases where they were faster. What is your lock tester? Does it test the lock code in isolation, or in situ? Thanks, J