[PATCH] mm/page_alloc: fix gcc compile warning

[Chen Wandun]

From: Chenwandun <chenwandun@xxxxxxxxxx>

mm/page_alloc.o: In function `page_alloc_init_late':
mm/page_alloc.c:1956: undefined reference to `zone_pcp_update'
mm/page_alloc.o:(.debug_addr+0x8350): undefined reference to `zone_pcp_update'
make: *** [vmlinux] Error 1

zone_pcp_update is defined in CONFIG_MEMORY_HOTPLUG,
so add ifdef when calling zone_pcp_update.

Signed-off-by: Chenwandun <chenwandun@xxxxxxxxxx>
---
 mm/page_alloc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f9488ef..8513150 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1952,8 +1952,10 @@ void __init page_alloc_init_late(void)
 	 * so the pcpu batch and high limits needs to be updated or the limits
 	 * will be artificially small.
 	 */
+#ifdef CONFIG_MEMORY_HOTPLUG
 	for_each_populated_zone(zone)
 		zone_pcp_update(zone);
+#endif
 
 	/*
 	 * We initialized the rest of the deferred pages.  Permanently disable
-- 
2.7.4