memcg: bugfix for memory hotplug

The start pfn calculation in page_cgroup's memory hotplug notifier chain
is wrong.

Tested-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index f59d797dc5a9..1223d927904d 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -165,7 +165,7 @@ int online_page_cgroup(unsigned long start_pfn,
         unsigned long start, end, pfn;
         int fail = 0;
 
-        start = start_pfn & (PAGES_PER_SECTION - 1);
+        start = start_pfn & ~(PAGES_PER_SECTION - 1);
         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 
         for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
@@ -188,7 +188,7 @@ int offline_page_cgroup(unsigned long start_pfn,
 {
         unsigned long start, end, pfn;
 
-        start = start_pfn & (PAGES_PER_SECTION - 1);
+        start = start_pfn & ~(PAGES_PER_SECTION - 1);
         end = ALIGN(start_pfn + nr_pages, PAGES_PER_SECTION);
 
         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)