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: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Wen 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c370491..de9cb14 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -581,6 +581,12 @@
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 @@
*/
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 @@
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 @@
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);