Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753510Ab3C1VR4 (ORCPT ); Thu, 28 Mar 2013 17:17:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57357 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752768Ab3C1VRz (ORCPT ); Thu, 28 Mar 2013 17:17:55 -0400 Message-ID: <5154B322.90705@redhat.com> Date: Thu, 28 Mar 2013 17:16:18 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Michel Lespinasse CC: Alex Shi , Ingo Molnar , David Howells , Peter Zijlstra , Thomas Gleixner , Yuanhan Liu , Peter Hurley , Dave Chinner , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 09/13] rwsem: skip initial trylock in rwsem_down_write_failed References: <1363344869-15732-1-git-send-email-walken@google.com> <1363344869-15732-10-git-send-email-walken@google.com> In-Reply-To: <1363344869-15732-10-git-send-email-walken@google.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 543 Lines: 14 On 03/15/2013 06:54 AM, Michel Lespinasse wrote: > We can skip the initial trylock in rwsem_down_write_failed() if there are > known active lockers already, thus saving one likely-to-fail cmpxchg. > > Signed-off-by: Michel Lespinasse Acked-by: Rik van Riel -- 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/