From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753204AbbIAPhm (ORCPT ); Tue, 1 Sep 2015 11:37:42 -0400 Received: from mail-qk0-f169.google.com ([209.85.220.169]:33779 "EHLO mail-qk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752542AbbIAPhl (ORCPT ); Tue, 1 Sep 2015 11:37:41 -0400 Message-ID: <55e5c643.04c0370a.45f82.58bb@mx.google.com> Date: Tue, 01 Sep 2015 08:37:39 -0700 (PDT) From: Yasuaki Ishimatsu To: Changsheng Liu Cc: , , , , , , , , Changsheng Liu Subject: Re: [PATCH V4] mm: memory hot-add: memory can not be added to movable zone defaultly In-Reply-To: <1441000720-28506-1-git-send-email-liuchangsheng@inspur.com> References: <0bc3aaab6cea54112f1c444880f9b832@s.corp-email.com> <1441000720-28506-1-git-send-email-liuchangsheng@inspur.com> X-Mailer: Sylpheed 3.4.3 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 31 Aug 2015 01:58:40 -0400 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 > 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 system boots up without movable_node, kernel behavior is changed by the patch. And you syould consider other zone. How about it. The patch is no build and test. --- mm/memory_hotplug.c | 36 ++++++++++++++++++++++++++++++++---- 1 files changed, 32 insertions(+), 4 deletions(-) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 6da82bc..321595d 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1198,6 +1198,8 @@ 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_zone and added memory does not overlap + * other zone except for 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) @@ -1205,14 +1207,40 @@ 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 *zone; + enum zone_type zt = ZONE_MOVABLE - 1; + + /* + * If memory is added after ZONE_MOVALBE, the memory is managed as + * movable. + */ + if (!zone_is_empty(movable_zone) && + (movable_zone->zone_start_pfn <= start_pfn)) + return 1; - if (zone_is_empty(movable_zone)) + if (!movable_node_is_enabled()) return 0; - if (movable_zone->zone_start_pfn <= start_pfn) - return 1; + /* + * Find enabled zone and check the added memory. + * If the memory is added after the enabled zone, the memory is + * managed as movable. + * + * If all zones are empty, the memory is also managed as movable. + */ + for (; zt >= ZONE_DMA; zt--) { + zone = pgdat->node_zones + zt; - return 0; + if (zone_is_empty(zone)) + continue; + + if (zone_end_pfn(zone) <= start_pfn) + return 1; + else + return 0; + } + + return 1; } int zone_for_memory(int nid, u64 start, u64 size, int zone_default) -- 1.7.1 > > if (zone_is_empty(movable_zone)) > return 0; > -- > 1.7.1 >