Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935763Ab3DHThg (ORCPT ); Mon, 8 Apr 2013 15:37:36 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:47919 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935713Ab3DHThf (ORCPT ); Mon, 8 Apr 2013 15:37:35 -0400 Message-ID: <51631C70.8010404@linux.vnet.ibm.com> Date: Mon, 08 Apr 2013 12:37:20 -0700 From: Cody P Schafer User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Simon Jeons CC: Andrew Morton , Mel Gorman , Linux MM , LKML Subject: Re: [PATCH 0/3] mm: fixup changers of per cpu pageset's ->high and ->batch References: <1365194030-28939-1-git-send-email-cody@linux.vnet.ibm.com> <5160CC94.6040909@gmail.com> In-Reply-To: <5160CC94.6040909@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13040819-7182-0000-0000-000006247C0C Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 851 Lines: 22 On 04/06/2013 06:32 PM, Simon Jeons wrote: > Hi Cody, > On 04/06/2013 04:33 AM, Cody P Schafer wrote: >> In one case while modifying the ->high and ->batch fields of per cpu >> pagesets >> we're unneededly using stop_machine() (patches 1 & 2), and in another >> we don't have any >> syncronization at all (patch 3). > > Do you mean stop_machine() is used for syncronization between each > online cpu? > I mean that it looks like synchronization between cpus is unneeded because of how per cpu pagesets are used, so stop_machine() (which does provide syncro between all cpus) is unnecessarily "strong". -- 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/