From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by kanga.kvack.org (Postfix) with ESMTP id 792896B0253 for ; Tue, 25 Aug 2015 07:13:11 -0400 (EDT) Received: by wicne3 with SMTP id ne3so11693267wic.0 for ; Tue, 25 Aug 2015 04:13:10 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id ma1si38245975wjb.20.2015.08.25.04.13.09 for (version=TLS1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 25 Aug 2015 04:13:10 -0700 (PDT) Subject: Re: [PATCH] Memory hot added,The memory can not been added to movable zone References: <1439972306-50845-1-git-send-email-liuchangsheng@inspur.com> <20150819165029.665b89d7ab3228185460172c@linux-foundation.org> <55D57071.1080901@inspur.com> <55db6d6d.82d1370a.dd0ff.6055@mx.google.com> <55DC4294.2020407@inspur.com> From: Vlastimil Babka Message-ID: <55DC4DC3.30509@suse.cz> Date: Tue, 25 Aug 2015 13:13:07 +0200 MIME-Version: 1.0 In-Reply-To: <55DC4294.2020407@inspur.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Changsheng Liu , Yasuaki Ishimatsu , Andrew Morton Cc: isimatu.yasuaki@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, yanxiaofeng@inspur.com, Changsheng Liu On 08/25/2015 12:25 PM, Changsheng Liu wrote: > Thanks very much for your review, I can move the memory from normal zone > to movable zone succesfully. > And thank you for let me understand the memory mechanism better. > a?? 2015/8/25 3:15, Yasuaki Ishimatsu a??e??: So you agree to drop the patch from -mm? >> Hi >> On Thu, 20 Aug 2015 14:15:13 +0800 >> Changsheng Liu wrote: >> >>> Hi Andrew Morton: >>> First, thanks very much for your review, I will update codes according >>> to your suggestio >>> >>> a?? 2015/8/20 7:50, Andrew Morton a??e??: >>>> On Wed, 19 Aug 2015 04:18:26 -0400 Changsheng Liu wrote: >>>> >>>>> From: Changsheng Liu >>>>> >>>>> When memory hot added, the function should_add_memory_movable >>>>> always return 0,because the movable zone is empty, >>>>> so the memory that hot added will add to normal zone even if >>>>> we want to remove the memory. >>>>> So we change the function should_add_memory_movable,if the user >>>>> config CONFIG_MOVABLE_NODE it will return 1 when >>>>> movable zone is empty >>>> I cleaned this up a bit: >>>> >>>> : Subject: mm: memory hot-add: memory can not been added to movable zone >>>> : >>>> : When memory is hot added, should_add_memory_movable() always returns 0 >>>> : because the movable zone is empty, so the memory that was hot added will >>>> : add to the normal zone even if we want to remove the memory. >>>> : >>>> : So we change should_add_memory_movable(): if the user config >>>> : CONFIG_MOVABLE_NODE it will return 1 when the movable zone is empty. >>>> >>>> But I don't understand the "even if we want to remove the memory". >>>> This is hot-add, not hot-remove. What do you mean here? >>> After the system startup, we hot added one memory. After some time >>> we wanted to hot remove the memroy that was hot added, >>> but we could not offline some memory blocks successfully because >>> the memory was added to normal zone defaultly and the value of the file >>> named removable under some memory blocks is 0. >> For this, we prepared online_movable. When memory is onlined by online_movable, >> the memory move from ZONE_NORMAL to ZONE_MOVABLE. >> >> Ex. >> # echo online_movable > /sys/devices/system/memory/memoryXXX/state >> >> Thanks, >> Yasuaki Ishimatsu >> >>> we checked the value of the file under some memory blocks as follows: >>> "cat /sys/devices/system/memory/ memory***/removable" >>> When memory being hot added we let the memory be added to movable >>> zone, >>> so we will be able to hot remove the memory that have been hot added >>>>> --- a/mm/memory_hotplug.c >>>>> +++ b/mm/memory_hotplug.c >>>>> @@ -1198,9 +1198,13 @@ static int should_add_memory_movable(int nid, u64 start, u64 size) >>>>> pg_data_t *pgdat = NODE_DATA(nid); >>>>> struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE; >>>>> >>>>> - if (zone_is_empty(movable_zone)) >>>>> + if (zone_is_empty(movable_zone)) { >>>>> + #ifdef CONFIG_MOVABLE_NODE >>>>> + return 1; >>>>> + #else >>>>> return 0; >>>>> - >>>>> + #endif >>>>> + } >>>>> if (movable_zone->zone_start_pfn <= start_pfn) >>>>> return 1; >>>> Cleaner: >>>> >>>> --- a/mm/memory_hotplug.c~memory-hot-addedthe-memory-can-not-been-added-to-movable-zone-fix >>>> +++ a/mm/memory_hotplug.c >>>> @@ -1181,13 +1181,9 @@ static int should_add_memory_movable(int >>>> pg_data_t *pgdat = NODE_DATA(nid); >>>> struct zone *movable_zone = pgdat->node_zones + ZONE_MOVABLE; >>>> >>>> - if (zone_is_empty(movable_zone)) { >>>> - #ifdef CONFIG_MOVABLE_NODE >>>> - return 1; >>>> - #else >>>> - return 0; >>>> - #endif >>>> - } >>>> + if (zone_is_empty(movable_zone)) >>>> + return IS_ENABLED(CONFIG_MOVABLE_NODE); >>>> + >>>> if (movable_zone->zone_start_pfn <= start_pfn) >>>> return 1; >>>> >>>> _ >>>> >>>> . >>>> >> . >> > -- 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