[PATCH] mm: PageLRU no testset
PG_lru is protected by zone->lru_lock. It does not need TestSet/TestClear
operations.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index acb7611..40fb378 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1042,9 +1042,10 @@
if (PageLRU(page)) {
struct zone *zone = page_zone(page);
spin_lock_irq(&zone->lru_lock);
- if (TestClearPageLRU(page)) {
+ if (PageLRU(page)) {
ret = 1;
get_page(page);
+ ClearPageLRU(page);
if (PageActive(page))
del_page_from_active_list(zone, page);
else
@@ -1085,6 +1086,8 @@
page = lru_to_page(src);
prefetchw_prev_lru_page(page, src, flags);
+ BUG_ON(!PageLRU(page));
+
list_del(&page->lru);
if (unlikely(get_page_testone(page))) {
/*
@@ -1100,8 +1103,7 @@
* the page is not being freed elsewhere -- the page release
* code relies on it.
*/
- if (!TestClearPageLRU(page))
- BUG();
+ ClearPageLRU(page);
list_add(&page->lru, dst);
nr_taken++;
}
@@ -1156,8 +1158,8 @@
*/
while (!list_empty(&page_list)) {
page = lru_to_page(&page_list);
- if (TestSetPageLRU(page))
- BUG();
+ BUG_ON(PageLRU(page));
+ SetPageLRU(page);
list_del(&page->lru);
if (PageActive(page))
add_page_to_active_list(zone, page);
@@ -1276,8 +1278,8 @@
while (!list_empty(&l_inactive)) {
page = lru_to_page(&l_inactive);
prefetchw_prev_lru_page(page, &l_inactive, flags);
- if (TestSetPageLRU(page))
- BUG();
+ BUG_ON(PageLRU(page));
+ SetPageLRU(page);
if (!TestClearPageActive(page))
BUG();
list_move(&page->lru, &zone->inactive_list);
@@ -1305,8 +1307,8 @@
while (!list_empty(&l_active)) {
page = lru_to_page(&l_active);
prefetchw_prev_lru_page(page, &l_active, flags);
- if (TestSetPageLRU(page))
- BUG();
+ BUG_ON(PageLRU(page));
+ SetPageLRU(page);
BUG_ON(!PageActive(page));
list_move(&page->lru, &zone->active_list);
pgmoved++;