From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx167.postini.com [74.125.245.167]) by kanga.kvack.org (Postfix) with SMTP id AC31E6B0005 for ; Sun, 7 Apr 2013 11:39:01 -0400 (EDT) Received: by mail-vc0-f174.google.com with SMTP id kw10so2084165vcb.33 for ; Sun, 07 Apr 2013 08:39:00 -0700 (PDT) Message-ID: <5161931A.8060501@gmail.com> Date: Sun, 07 Apr 2013 11:39:06 -0400 From: KOSAKI Motohiro MIME-Version: 1.0 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: owner-linux-mm@kvack.org List-ID: To: Cody P Schafer Cc: Andrew Morton , Mel Gorman , Linux MM , LKML , kosaki.motohiro@gmail.com (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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org