mm: pagecache insertion fewer atomics

Setting and clearing the page locked when inserting it into swapcache /
pagecache when it has no other references can use non-atomic page flags
operations because no other CPU may be operating on it at this time.

This saves one atomic operation when inserting a page into pagecache.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 4b6c4d8d26b8..7334b2b6c4c6 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -299,14 +299,14 @@ extern int __lock_page_killable(struct page *page);
 extern void __lock_page_nosync(struct page *page);
 extern void unlock_page(struct page *page);
 
-static inline void set_page_locked(struct page *page)
+static inline void __set_page_locked(struct page *page)
 {
-	set_bit(PG_locked, &page->flags);
+	__set_bit(PG_locked, &page->flags);
 }
 
-static inline void clear_page_locked(struct page *page)
+static inline void __clear_page_locked(struct page *page)
 {
-	clear_bit(PG_locked, &page->flags);
+	__clear_bit(PG_locked, &page->flags);
 }
 
 static inline int trylock_page(struct page *page)
@@ -438,17 +438,17 @@ extern void __remove_from_page_cache(struct page *page);
 
 /*
  * Like add_to_page_cache_locked, but used to add newly allocated pages:
- * the page is new, so we can just run set_page_locked() against it.
+ * the page is new, so we can just run __set_page_locked() against it.
  */
 static inline int add_to_page_cache(struct page *page,
 		struct address_space *mapping, pgoff_t offset, gfp_t gfp_mask)
 {
 	int error;
 
-	set_page_locked(page);
+	__set_page_locked(page);
 	error = add_to_page_cache_locked(page, mapping, offset, gfp_mask);
 	if (unlikely(error))
-		clear_page_locked(page);
+		__clear_page_locked(page);
 	return error;
 }