Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933966Ab3DGPjD (ORCPT ); Sun, 7 Apr 2013 11:39:03 -0400 Received: from mail-vc0-f181.google.com ([209.85.220.181]:35759 "EHLO mail-vc0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933945Ab3DGPjB (ORCPT ); Sun, 7 Apr 2013 11:39:01 -0400 Message-ID: <5161931A.8060501@gmail.com> Date: Sun, 07 Apr 2013 11:39:06 -0400 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:17.0) Gecko/20130307 Thunderbird/17.0.4 MIME-Version: 1.0 To: Cody P Schafer CC: Andrew Morton , Mel Gorman , Linux MM , LKML , kosaki.motohiro@gmail.com Subject: Re: [PATCH 2/3] mm/page_alloc: convert zone_pcp_update() to use on_each_cpu() instead of stop_machine() References: <1365194030-28939-1-git-send-email-cody@linux.vnet.ibm.com> <1365194030-28939-3-git-send-email-cody@linux.vnet.ibm.com> In-Reply-To: <1365194030-28939-3-git-send-email-cody@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1134 Lines: 27 (4/5/13 4:33 PM), Cody P Schafer wrote: > No off-cpu users of the percpu pagesets exist. > > zone_pcp_update()'s goal is to adjust the ->high and ->mark members of a > percpu pageset based on a zone's ->managed_pages. We don't need to drain > the entire percpu pageset just to modify these fields. Avoid calling > setup_pageset() (and the draining required to call it) and instead just > set the fields' values. > > This does change the behavior of zone_pcp_update() as the percpu > pagesets will not be drained when zone_pcp_update() is called (they will > end up being shrunk, not completely drained, later when a 0-order page > is freed in free_hot_cold_page()). > > Signed-off-by: Cody P Schafer NAK. 1) zone_pcp_update() is only used from memory hotplug and it require page drain. 2) stop_machin is used for avoiding race. just removing it is insane. -- 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/