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>
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 4b6c4d8..7334b2b 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -299,14 +299,14 @@
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 @@
/*
* 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;
}