memory hotplug: update zone pcp at memory online

In my test, 128M memory is hot added, but zone's pcp batch is 0, which is
an obvious error.  When pages are onlined, zone pcp should be updated
accordingly.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Yakui Zhao <yakui.zhao@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9a72cc78e6b8..d3c8ae7c8015 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1058,6 +1058,8 @@ extern void setup_per_cpu_pageset(void);
 static inline void setup_per_cpu_pageset(void) {}
 #endif
 
+extern void zone_pcp_update(struct zone *zone);
+
 /* nommu.c */
 extern atomic_long_t mmap_pages_allocated;