From: Nick Piggin <npiggin@suse.de>
Date: Wed, 22 Mar 2006 08:08:00 +0000 (-0800)
Subject: [PATCH] mm: less atomic ops
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=674539115cc88473f623581e1d53c0e2ecef2179;p=openwrt%2Fstaging%2Fblogic.git

[PATCH] mm: less atomic ops

In the page release paths, we can be sure that nobody will mess with our
page->flags because the refcount has dropped to 0.  So no need for atomic
operations here.

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/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 8ac854f7f190..3b6723dfaff3 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -32,7 +32,7 @@ del_page_from_lru(struct zone *zone, struct page *page)
 {
 	list_del(&page->lru);
 	if (PageActive(page)) {
-		ClearPageActive(page);
+		__ClearPageActive(page);
 		zone->nr_active--;
 	} else {
 		zone->nr_inactive--;
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 5d1e7bd85107..da71d63df465 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -242,10 +242,12 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
 #define PageLRU(page)		test_bit(PG_lru, &(page)->flags)
 #define SetPageLRU(page)	set_bit(PG_lru, &(page)->flags)
 #define ClearPageLRU(page)	clear_bit(PG_lru, &(page)->flags)
+#define __ClearPageLRU(page)	__clear_bit(PG_lru, &(page)->flags)
 
 #define PageActive(page)	test_bit(PG_active, &(page)->flags)
 #define SetPageActive(page)	set_bit(PG_active, &(page)->flags)
 #define ClearPageActive(page)	clear_bit(PG_active, &(page)->flags)
+#define __ClearPageActive(page)	__clear_bit(PG_active, &(page)->flags)
 
 #define PageSlab(page)		test_bit(PG_slab, &(page)->flags)
 #define SetPageSlab(page)	set_bit(PG_slab, &(page)->flags)
diff --git a/mm/swap.c b/mm/swap.c
index cf88226cf96d..91b7e2026f69 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -215,7 +215,7 @@ void fastcall __page_cache_release(struct page *page)
 
 		spin_lock_irqsave(&zone->lru_lock, flags);
 		BUG_ON(!PageLRU(page));
-		ClearPageLRU(page);
+		__ClearPageLRU(page);
 		del_page_from_lru(zone, page);
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 	}
@@ -266,7 +266,7 @@ void release_pages(struct page **pages, int nr, int cold)
 				spin_lock_irq(&zone->lru_lock);
 			}
 			BUG_ON(!PageLRU(page));
-			ClearPageLRU(page);
+			__ClearPageLRU(page);
 			del_page_from_lru(zone, page);
 		}