From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965227AbbKDKVH (ORCPT ); Wed, 4 Nov 2015 05:21:07 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:28027 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965139AbbKDKVB (ORCPT ); Wed, 4 Nov 2015 05:21:01 -0500 Message-ID: <5639DBDE.6000306@huawei.com> Date: Wed, 4 Nov 2015 18:20:14 +0800 From: Xishi Qiu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: liuchangsheng CC: , , , , , , , , , Wang Nan , Dave Hansen , Yinghai Lu , Tang Chen , Toshi Kani Subject: Re: [PATCH V8] mm: memory hot-add: hot-added memory can not be added to movable zone by default References: <1446625415-11941-1-git-send-email-liuchangsheng@inspur.com> In-Reply-To: <1446625415-11941-1-git-send-email-liuchangsheng@inspur.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.25.179] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.5639DBF1.0138,ss=1,re=0.000,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2011-05-27 18:58:46 X-Mirapoint-Loop-Id: 59b7d9e26355bb979589819976a46c0d Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/11/4 16:23, liuchangsheng wrote: > After the user config CONFIG_MOVABLE_NODE, > When the memory is hot added, should_add_memory_movable() return 0 > because all zones including ZONE_MOVABLE are empty, > so the memory that was hot added will be assigned to ZONE_NORMAL, > and we need using the udev rules to online the memory automatically: > SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", > ATTR{state}="online_movable" > The memory block onlined by udev must be adjacent to ZONE_MOVABLE. > The events of memory section are notified to udev asynchronously, Hi Yasuaki, If udev onlines memory in descending order, like 3->2->1->0, it will success, but we notifiy to udev in ascending order, like 0->1->2->3, so the udev rules cannot online memory as movable, right? > so it can not ensure that the memory block onlined by udev is > adjacent to ZONE_MOVABLE.So it can't ensure memory online always success. > But we want the whole node to be added to ZONE_MOVABLE by default. > > So we change should_add_memory_movable(): if the user config > CONFIG_MOVABLE_NODE and movable_node kernel option > and the ZONE_NORMAL is empty or the pfn of the hot-added memory > is after the end of the ZONE_NORMAL it will always return 1 > and then the whole node will be added to ZONE_MOVABLE by default. > If we want the node to be assigned to ZONE_NORMAL, > we can do it as follows: > "echo online_kernel > /sys/devices/system/memory/memoryXXX/state" > The order should like 0->1->2->3, right? 3->2->1->0 will be failed. > Signed-off-by: liuchangsheng > Signed-off-by: Xiaofeng Yan > Tested-by: Dongdong Fan > Reviewed-by: > Cc: Wang Nan > Cc: Dave Hansen > Cc: Yinghai Lu > Cc: Tang Chen > Cc: Yasuaki Ishimatsu > Cc: Toshi Kani > Cc: Xishi Qiu > --- > mm/memory_hotplug.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index aa992e2..8617b9f 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1201,6 +1201,9 @@ static int check_hotplug_memory_range(u64 start, u64 size) > /* > * If movable zone has already been setup, newly added memory should be check. > * If its address is higher than movable zone, it should be added as movable. > + * And if system boots up with movable_node and config CONFIG_MOVABLE_NOD and > + * added memory does not overlap the zone before MOVABLE_ZONE, > + * the memory is added as movable. > * Without this check, movable zone may overlap with other zone. > */ > static int should_add_memory_movable(int nid, u64 start, u64 size) > @@ -1208,6 +1211,10 @@ 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 *pre_zone = pgdat->node_zones + (ZONE_MOVABLE - 1); > + > + if (movable_node_is_enabled() && (zone_end_pfn(pre_zone) <= start_pfn)) > + return 1; > Looks good to me. How about add some comment in mm/Kconfig? Thanks, Xishi Qiu > if (zone_is_empty(movable_zone)) > return 0;