thp: compound_trans_order
Read compound_trans_order safe. Noop for CONFIG_TRANSPARENT_HUGEPAGE=n.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: 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>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f4ea341..741206f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1027,10 +1027,6 @@
{
struct page_cgroup *pc;
struct mem_cgroup_per_zone *mz;
- int page_size = PAGE_SIZE;
-
- if (PageTransHuge(page))
- page_size <<= compound_order(page);
if (mem_cgroup_disabled())
return NULL;
@@ -2286,8 +2282,10 @@
int ret;
int page_size = PAGE_SIZE;
- if (PageTransHuge(page))
+ if (PageTransHuge(page)) {
page_size <<= compound_order(page);
+ VM_BUG_ON(!PageTransHuge(page));
+ }
pc = lookup_page_cgroup(page);
/* can happen at boot */
@@ -2558,8 +2556,10 @@
if (PageSwapCache(page))
return NULL;
- if (PageTransHuge(page))
+ if (PageTransHuge(page)) {
page_size <<= compound_order(page);
+ VM_BUG_ON(!PageTransHuge(page));
+ }
count = page_size >> PAGE_SHIFT;
/*
