From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755273AbbHXTQA (ORCPT ); Mon, 24 Aug 2015 15:16:00 -0400 Received: from mail-qg0-f46.google.com ([209.85.192.46]:36779 "EHLO mail-qg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753974AbbHXTP6 (ORCPT ); Mon, 24 Aug 2015 15:15:58 -0400 Message-ID: <55db6d6d.82d1370a.dd0ff.6055@mx.google.com> Date: Mon, 24 Aug 2015 12:15:57 -0700 (PDT) From: Yasuaki Ishimatsu To: Changsheng Liu Cc: Andrew Morton , , , , , , Changsheng Liu Subject: Re: [PATCH] Memory hot added,The memory can not been added to movable zone In-Reply-To: <55D57071.1080901@inspur.com> References: <1439972306-50845-1-git-send-email-liuchangsheng@inspur.com> <20150819165029.665b89d7ab3228185460172c@linux-foundation.org> <55D57071.1080901@inspur.com> X-Mailer: Sylpheed 3.4.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > > 在 2015/8/20 7:50, Andrew Morton 写道: > > 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; > > > > _ > > > > . > > >