From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757233Ab2ECSHX (ORCPT ); Thu, 3 May 2012 14:07:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:31545 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753270Ab2ECSHW (ORCPT ); Thu, 3 May 2012 14:07:22 -0400 Message-ID: <4FA2C946.60006@redhat.com> Date: Thu, 03 May 2012 14:07:02 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120424 Thunderbird/12.0 MIME-Version: 1.0 To: rajman mekaco CC: Ingo Molnar , Peter Zijlstra , Paul Gortmaker , Andrew Morton , KOSAKI Motohiro , Minchan Kim , Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/1] mlock: split the shmlock_user_lock spinlock into per user_struct spinlock References: <1336066477-3964-1-git-send-email-rajman.mekaco@gmail.com> In-Reply-To: <1336066477-3964-1-git-send-email-rajman.mekaco@gmail.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 On 05/03/2012 01:34 PM, rajman mekaco wrote: > The user_shm_lock and user_shm_unlock functions use a single global > spinlock for protecting the user->locked_shm. > > This is an overhead for multiple CPUs calling this code even if they > are having different user_struct. > > Remove the global shmlock_user_lock and introduce and use a new > spinlock inside of the user_struct structure. > > Signed-off-by: rajman mekaco Reviewed-by: Rik van Riel