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Commit 74d42d8f authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Linus Torvalds
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memory_hotplug: ensure every online node has NORMAL memory 



Old memory hotplug code and new online/movable may cause a online node
don't have any normal memory, but memory-management acts bad when we have
nodes which is online but don't have any normal memory.  Example: it may
cause a bound task fail on all kernel allocation and cause the task can't
create task or create other kernel object.

So we disable non-normal-memory-node here, we will enable it when we
prepared.

Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarWen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e455a9b9

mm/memory_hotplug.c

+40 −0
Original line number Diff line number Diff line
@@ -581,6 +581,12 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, 
	return 0;

}



/* ensure every online node has NORMAL memory */

static bool can_online_high_movable(struct zone *zone)

{

	return node_state(zone_to_nid(zone), N_NORMAL_MEMORY);

}



/* check which state of node_states will be changed when online memory */

static void node_states_check_changes_online(unsigned long nr_pages,

	struct zone *zone, struct memory_notify *arg)
@@ -646,6 +652,12 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ 
	 */

	zone = page_zone(pfn_to_page(pfn));



	if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) &&

	    !can_online_high_movable(zone)) {

		unlock_memory_hotplug();

		return -1;

	}



	if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) {

		if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) {

			unlock_memory_hotplug();
@@ -1054,6 +1066,30 @@ check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) 
	return offlined;

}



/* ensure the node has NORMAL memory if it is still online */

static bool can_offline_normal(struct zone *zone, unsigned long nr_pages)

{

	struct pglist_data *pgdat = zone->zone_pgdat;

	unsigned long present_pages = 0;

	enum zone_type zt;



	for (zt = 0; zt <= ZONE_NORMAL; zt++)

		present_pages += pgdat->node_zones[zt].present_pages;



	if (present_pages > nr_pages)

		return true;



	present_pages = 0;

	for (; zt <= ZONE_MOVABLE; zt++)

		present_pages += pgdat->node_zones[zt].present_pages;



	/*

	 * we can't offline the last normal memory until all

	 * higher memory is offlined.

	 */

	return present_pages == 0;

}



/* check which state of node_states will be changed when offline memory */

static void node_states_check_changes_offline(unsigned long nr_pages,

		struct zone *zone, struct memory_notify *arg)
@@ -1141,6 +1177,10 @@ static int __ref __offline_pages(unsigned long start_pfn, 
	node = zone_to_nid(zone);

	nr_pages = end_pfn - start_pfn;



	ret = -EINVAL;

	if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages))

		goto out;



	/* set above range as isolated */

	ret = start_isolate_page_range(start_pfn, end_pfn,

				       MIGRATE_MOVABLE, true);