Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755690Ab3DPJNH (ORCPT ); Tue, 16 Apr 2013 05:13:07 -0400 Received: from mail-ee0-f51.google.com ([74.125.83.51]:54151 "EHLO mail-ee0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755354Ab3DPJNE (ORCPT ); Tue, 16 Apr 2013 05:13:04 -0400 Date: Tue, 16 Apr 2013 11:12:59 +0200 From: Ingo Molnar To: Waiman Long Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Paul E. McKenney" , David Howells , Dave Jones , Clark Williams , Peter Zijlstra , linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, "Chandramouleeswaran, Aswin" , Davidlohr Bueso , "Norton, Scott J" , Rik van Riel Subject: Re: [PATCH 0/3 v2] mutex: Improve mutex performance by doing less atomic-ops & better spinning Message-ID: <20130416091259.GC9569@gmail.com> References: <1366036679-9702-1-git-send-email-Waiman.Long@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1366036679-9702-1-git-send-email-Waiman.Long@hp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 25 * Waiman Long wrote: > [...] > > Patches 2 improves the mutex spinning process by reducing contention among the > spinners when competing for the mutex. This is done by using a MCS lock to put > the spinners in a queue so that only the first spinner will try to acquire the > mutex when it is available. This patch showed significant performance > improvement of +30% on the AIM7 fserver and new_fserver workload. Ok, that's really nice - and this approach has no arbitrary limits/tunings in it. Do you have a performance comparison to your first series (patches 1+2+3 IIRC) - how does this new series with MCS locking compare to the best previous result from that old series? Do we now achieve that level of performance? Thanks, Ingo -- 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/