From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752778AbbHaNJB (ORCPT ); Mon, 31 Aug 2015 09:09:01 -0400 Received: from mx2.suse.de ([195.135.220.15]:45787 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751841AbbHaNJA (ORCPT ); Mon, 31 Aug 2015 09:09:00 -0400 Subject: Re: [PATCH V4] mm: memory hot-add: memory can not be added to movable zone defaultly To: Changsheng Liu , akpm@linux-foundation.org, isimatu.yasuaki@jp.fujitsu.com, yasu.isimatu@gmail.com References: <1441000720-28506-1-git-send-email-liuchangsheng@inspur.com> Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, wunan@inspur.com, yanxiaofeng@inspur.com, fandd@inspur.com, Changsheng Liu From: Vlastimil Babka Message-ID: <55E451E8.1080005@suse.cz> Date: Mon, 31 Aug 2015 15:08:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1441000720-28506-1-git-send-email-liuchangsheng@inspur.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/31/2015 07:58 AM, Changsheng Liu wrote: > 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 Thanks for the credit for commenting on the previous versions of the patch. However, "Reviewed-by" currently means that the reviewer believes the patch is OK, so you can add it only if the reviewer offers it explicitly. See Documentation/SubmittingPatches section 13. There was a discussion on ksummit-discuss about adding a new tag for this case, but nothing was decided yet AFAIK. > 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; I wonder if the condition is true and ZONE_NORMAL exists (but it's empty?) if you intend to only add movable memory to a node, so you can still hot-remove it all with this patch? > > if (zone_is_empty(movable_zone)) > return 0; > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com [209.85.212.174]) by kanga.kvack.org (Postfix) with ESMTP id CEA616B0254 for ; Mon, 31 Aug 2015 09:09:01 -0400 (EDT) Received: by wicne3 with SMTP id ne3so74231513wic.0 for ; Mon, 31 Aug 2015 06:09:01 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id gn12si26708941wjc.137.2015.08.31.06.08.59 for (version=TLS1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 31 Aug 2015 06:09:00 -0700 (PDT) Subject: Re: [PATCH V4] mm: memory hot-add: memory can not be added to movable zone defaultly References: <1441000720-28506-1-git-send-email-liuchangsheng@inspur.com> From: Vlastimil Babka Message-ID: <55E451E8.1080005@suse.cz> Date: Mon, 31 Aug 2015 15:08:56 +0200 MIME-Version: 1.0 In-Reply-To: <1441000720-28506-1-git-send-email-liuchangsheng@inspur.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Changsheng Liu , akpm@linux-foundation.org, isimatu.yasuaki@jp.fujitsu.com, yasu.isimatu@gmail.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, wunan@inspur.com, yanxiaofeng@inspur.com, fandd@inspur.com, Changsheng Liu On 08/31/2015 07:58 AM, Changsheng Liu wrote: > 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 Thanks for the credit for commenting on the previous versions of the patch. However, "Reviewed-by" currently means that the reviewer believes the patch is OK, so you can add it only if the reviewer offers it explicitly. See Documentation/SubmittingPatches section 13. There was a discussion on ksummit-discuss about adding a new tag for this case, but nothing was decided yet AFAIK. > 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; I wonder if the condition is true and ZONE_NORMAL exists (but it's empty?) if you intend to only add movable memory to a node, so you can still hot-remove it all with this patch? > > if (zone_is_empty(movable_zone)) > return 0; > -- 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