mm: perform non-atomic test-clear of PG_mlocked on free
By the time PG_mlocked is cleared in the page freeing path, nobody else is
looking at our page->flags anymore.
It is thus safe to make the test-and-clear non-atomic and thereby removing
an unnecessary and expensive operation from a hotpath.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 81926c7..9242d13 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -557,7 +557,7 @@
unsigned long flags;
int i;
int bad = 0;
- int wasMlocked = TestClearPageMlocked(page);
+ int wasMlocked = __TestClearPageMlocked(page);
kmemcheck_free_shadow(page, order);
@@ -1026,7 +1026,7 @@
struct zone *zone = page_zone(page);
struct per_cpu_pages *pcp;
unsigned long flags;
- int wasMlocked = TestClearPageMlocked(page);
+ int wasMlocked = __TestClearPageMlocked(page);
kmemcheck_free_shadow(page, 0);