[PATCH] wait_table and zonelist initializing for memory hotadd: update zonelists
In current code, zonelist is considered to be build once, no modification.
But MemoryHotplug can add new zone/pgdat. It must be updated.
This patch modifies build_all_zonelists(). By this, build_all_zonelist() can
reconfig pgdat's zonelists.
To update them safety, this patch use stop_machine_run(). Other cpus don't
touch among updating them by using it.
In old version (V2 of node hotadd), kernel updated them after zone
initialization. But present_page of its new zone is still 0, because
online_page() is not called yet at this time. Build_zonelists() checks
present_pages to find present zone. It was too early. So, I changed it after
online_pages().
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 71da5c9..1b1ac3d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -127,6 +127,7 @@
unsigned long flags;
unsigned long onlined_pages = 0;
struct zone *zone;
+ int need_zonelists_rebuild = 0;
/*
* This doesn't need a lock to do pfn_to_page().
@@ -139,6 +140,14 @@
grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
pgdat_resize_unlock(zone->zone_pgdat, &flags);
+ /*
+ * If this zone is not populated, then it is not in zonelist.
+ * This means the page allocator ignores this zone.
+ * So, zonelist must be updated after online.
+ */
+ if (!populated_zone(zone))
+ need_zonelists_rebuild = 1;
+
for (i = 0; i < nr_pages; i++) {
struct page *page = pfn_to_page(pfn + i);
online_page(page);
@@ -149,5 +158,8 @@
setup_per_zone_pages_min();
+ if (need_zonelists_rebuild)
+ build_all_zonelists();
+
return 0;
}
