memory_hotplug: use pgdat_resize_lock() in online_pages()
mmzone.h documents node_size_lock (which pgdat_resize_lock() locks) as
follows:
* Must be held any time you expect node_start_pfn, node_present_pages
* or node_spanned_pages stay constant. [...]
So actually hold it when we update node_present_pages in online_pages().
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.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 1ad92b4..527c510 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -918,6 +918,7 @@
int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type)
{
+ unsigned long flags;
unsigned long onlined_pages = 0;
struct zone *zone;
int need_zonelists_rebuild = 0;
@@ -996,7 +997,11 @@
zone->managed_pages += onlined_pages;
zone->present_pages += onlined_pages;
+
+ pgdat_resize_lock(zone->zone_pgdat, &flags);
zone->zone_pgdat->node_present_pages += onlined_pages;
+ pgdat_resize_unlock(zone->zone_pgdat, &flags);
+
if (onlined_pages) {
node_states_set_node(zone_to_nid(zone), &arg);
if (need_zonelists_rebuild)
