From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752023AbbHaF7C (ORCPT ); Mon, 31 Aug 2015 01:59:02 -0400 Received: from unicom146.biz-email.net ([210.51.26.146]:1557 "EHLO unicom146.biz-email.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750812AbbHaF7A (ORCPT ); Mon, 31 Aug 2015 01:59:00 -0400 From: Changsheng Liu To: , , , CC: , , , , , , Changsheng Liu Subject: [PATCH V4] mm: memory hot-add: memory can not be added to movable zone defaultly Date: Mon, 31 Aug 2015 01:58:40 -0400 Message-ID: <1441000720-28506-1-git-send-email-liuchangsheng@inspur.com> X-Mailer: git-send-email 1.8.3.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.165.23.10] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Changsheng Liu After the user config CONFIG_MOVABLE_NODE and movable_node kernel option, When the memory is hot added, should_add_memory_movable() return 0 because all zones including movable zone are empty, so the memory that was hot added will be added to the normal zone and the normal zone will be created firstly. But we want the whole node to be added to movable zone defaultly. So we change should_add_memory_movable(): if the user config CONFIG_MOVABLE_NODE and movable_node kernel option it will always return 1 and all zones is empty at the same time, so that the movable zone will be created firstly and then the whole node will be added to movable zone defaultly. If we want the node to be added to normal zone, we can do it as follows: "echo online_kernel > /sys/devices/system/memory/memoryXXX/state" If the memory is added to movable zone defaultly, the user can offline it and add it to other zone again. But if the memory is added to normal zone defaultly, the user will not offline the memory used by kernel. Reviewed-by: Andrew Morton Reviewed-by: Yasuaki Ishimatsu Reviewed-by: Vlastimil Babka Reviewed-by: Xiaofeng Yan Signed-off-by: Changsheng Liu Tested-by: Dongdong Fan --- mm/memory_hotplug.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 26fbba7..d1149ff 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1197,6 +1197,11 @@ static int should_add_memory_movable(int nid, u64 start, u64 size) unsigned long start_pfn = start >> PAGE_SHIFT; pg_data_t *pgdat = NODE_DATA(nid); struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE; + struct zone *normal_zone = pgdat->node_zones + ZONE_NORMAL; + + if (movable_node_is_enabled() + && (zone_end_pfn(normal_zone) <= start_pfn)) + return 1; if (zone_is_empty(movable_zone)) return 0; -- 1.7.1