[PATCH] mm: page_alloc less atomics

More atomic operation removal from page allocator
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

include/linux/page-flags.h

@@ -328,8 +328,8 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
 #define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
 
 #define PageCompound(page)	test_bit(PG_compound, &(page)->flags)
-#define SetPageCompound(page)	set_bit(PG_compound, &(page)->flags)
-#define ClearPageCompound(page)	clear_bit(PG_compound, &(page)->flags)
+#define __SetPageCompound(page)	__set_bit(PG_compound, &(page)->flags)
+#define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)
 
 #ifdef CONFIG_SWAP
 #define PageSwapCache(page)	test_bit(PG_swapcache, &(page)->flags)

mm/page_alloc.c

@@ -190,7 +190,7 @@ static void prep_compound_page(struct page *page, unsigned long order)
 	for (i = 0; i < nr_pages; i++) {
 		struct page *p = page + i;
 
-		SetPageCompound(p);
+		__SetPageCompound(p);
 		set_page_private(p, (unsigned long)page);
 	}
 }
@@ -209,7 +209,7 @@ static void destroy_compound_page(struct page *page, unsigned long order)
 		if (unlikely(!PageCompound(p) |
 				(page_private(p) != (unsigned long)page)))
 			bad_page(page);
-		ClearPageCompound(p);
+		__ClearPageCompound(p);
 	}
 }