From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932173Ab2GEJwi (ORCPT ); Thu, 5 Jul 2012 05:52:38 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:4927 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752950Ab2GEJwh (ORCPT ); Thu, 5 Jul 2012 05:52:37 -0400 From: Jiang Liu To: Andrew Morton , Mel Gorman , Michal Hocko , Minchan Kim CC: Jiang Liu , Rusty Russell , Yinghai Lu , Tony Luck , KAMEZAWA Hiroyuki , KOSAKI Motohiro , David Rientjes , Bjorn Helgaas , Keping Chen , , , Jiang Liu Subject: [PATCH 2/4] mm/hotplug: correctly add new zone to all other nodes' zone lists Date: Thu, 5 Jul 2012 17:45:30 +0800 Message-ID: <1341481532-1700-2-git-send-email-jiang.liu@huawei.com> X-Mailer: git-send-email 1.7.8.msysgit.0 In-Reply-To: <1341481532-1700-1-git-send-email-jiang.liu@huawei.com> References: <1341481532-1700-1-git-send-email-jiang.liu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.108.108.229] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When online_pages() is called to add new memory to an empty zone, it rebuilds all zone lists by calling build_all_zonelists(). But there's a bug which prevents the new zone to be added to other nodes' zone lists. online_pages() { build_all_zonelists() ..... node_set_state(zone_to_nid(zone), N_HIGH_MEMORY) } Here the node of the zone is put into N_HIGH_MEMORY state after calling build_all_zonelists(), but build_all_zonelists() only adds zones from nodes in N_HIGH_MEMORY state to the fallback zone lists. build_all_zonelists() ->__build_all_zonelists() ->build_zonelists() ->find_next_best_node() ->for_each_node_state(n, N_HIGH_MEMORY) So memory in the new zone will never be used by other nodes, and it may cause strange behavor when system is under memory pressure. So put node into N_HIGH_MEMORY state before calling build_all_zonelists(). Signed-Off: Jianguo Wu Signed-off-by: Jiang Liu --- mm/memory_hotplug.c | 15 ++++++++------- 1 files changed, 8 insertions(+), 7 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index f93c5b5..bce80c7 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -512,19 +512,20 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages) zone->present_pages += onlined_pages; zone->zone_pgdat->node_present_pages += onlined_pages; - if (need_zonelists_rebuild) - build_all_zonelists(NULL, zone); - else - zone_pcp_update(zone); + if (onlined_pages) { + node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); + if (need_zonelists_rebuild) + build_all_zonelists(NULL, zone); + else + zone_pcp_update(zone); + } mutex_unlock(&zonelists_mutex); init_per_zone_wmark_min(); - if (onlined_pages) { + if (onlined_pages) kswapd_run(zone_to_nid(zone)); - node_set_state(zone_to_nid(zone), N_HIGH_MEMORY); - } vm_total_pages = nr_free_pagecache_pages(); -- 1.7.1