From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759213Ab3BTKkt (ORCPT ); Wed, 20 Feb 2013 05:40:49 -0500 Received: from mail-ea0-f176.google.com ([209.85.215.176]:33662 "EHLO mail-ea0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759197Ab3BTKkr (ORCPT ); Wed, 20 Feb 2013 05:40:47 -0500 Date: Wed, 20 Feb 2013 11:40:43 +0100 From: Ingo Molnar To: Alex Shi Cc: Michel Lespinasse , linux-kernel@vger.kernel.org, anton@samba.org, hpa@zytor.com, arjan@linux.intel.com, a.p.zijlstra@chello.nl, torvalds@linux-foundation.org, yuanhan.liu@linux.intel.com, dhowells@redhat.com, akpm@linux-foundation.org, tglx@linutronix.de Subject: Re: [PATCH 0/4] rwsem: Implement writer lock-stealing Message-ID: <20130220104043.GB7691@gmail.com> References: <1360377937-16297-1-git-send-email-walken@google.com> <511B9B4F.3060404@intel.com> <20130213144932.GA14260@gmail.com> <51248E59.2010907@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51248E59.2010907@intel.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 * Alex Shi wrote: > > Alex, could you go through my patch and see if there is > > anything you find objectionable ? (if not about the details, > > at least about the general approach of enabling writer lock > > stealing on the fast path) > > I did a quick review on the patchset and tested the patches > 1~3, and 1~3 plus 4th, my patch plus 4th. > > The patch looks much complicated, and also goes writing slow > path to steal locking. My patch looks quite straight and > simple. > > This 1~3 patch has very very similar performance effect with > mine. > > The highlight patch is the 4th, seems it can provide about ~2% > aim7 performance gain(base on both of mine or patches 1~3) on > my 4S NHM EX machine. That speedup would be nice to have. Thanks, Ingo