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From: Nick Piggin <npiggin@suse.de>
To: Linux Memory Management <linux-mm@kvack.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: Hugh Dickins <hugh@veritas.com>, Andrew Morton <akpm@osdl.org>,
	Andrea Arcangeli <andrea@suse.de>, Nick Piggin <npiggin@suse.de>,
	Linus Torvalds <torvalds@osdl.org>,
	David Miller <davem@davemloft.net>
Subject: [patch 4/4] mm: less atomic ops
Date: Wed, 18 Jan 2006 11:41:09 +0100 (CET)	[thread overview]
Message-ID: <20060118024149.10241.6312.sendpatchset@linux.site> (raw)
In-Reply-To: <20060118024106.10241.69438.sendpatchset@linux.site>

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>

Index: linux-2.6/include/linux/page-flags.h
===================================================================
--- linux-2.6.orig/include/linux/page-flags.h
+++ linux-2.6/include/linux/page-flags.h
@@ -247,10 +247,12 @@ extern void __mod_page_state_offset(unsi
 #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)
Index: linux-2.6/mm/swap.c
===================================================================
--- linux-2.6.orig/mm/swap.c
+++ linux-2.6/mm/swap.c
@@ -204,7 +204,7 @@ void fastcall __page_cache_release(struc
 		struct zone *zone = page_zone(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);
 	}
@@ -248,7 +248,7 @@ void release_pages(struct page **pages, 
 				spin_lock_irq(&zone->lru_lock);
 			}
 			BUG_ON(!PageLRU(page));
-			ClearPageLRU(page);
+			__ClearPageLRU(page);
 			del_page_from_lru(zone, page);
 		}
 
Index: linux-2.6/include/linux/mm_inline.h
===================================================================
--- linux-2.6.orig/include/linux/mm_inline.h
+++ linux-2.6/include/linux/mm_inline.h
@@ -32,7 +32,7 @@ del_page_from_lru(struct zone *zone, str
 {
 	list_del(&page->lru);
 	if (PageActive(page)) {
-		ClearPageActive(page);
+		__ClearPageActive(page);
 		zone->nr_active--;
 	} else {
 		zone->nr_inactive--;

  parent reply	other threads:[~2006-01-18 10:41 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-01-18 10:40 [patch 0/4] mm: de-skew page refcount Nick Piggin
2006-01-18 10:40 ` [patch 1/4] mm: page refcount use atomic primitives Nick Piggin
2006-01-18 10:40 ` [patch 2/4] mm: PageLRU no testset Nick Piggin
2006-01-19 17:48   ` Nikita Danilov
2006-01-19 18:10     ` Nick Piggin
2006-01-18 10:40 ` [patch 3/3] mm: PageActive " Nick Piggin
2006-01-18 14:13   ` Marcelo Tosatti
2006-01-19 14:50     ` Nick Piggin
2006-01-19 16:52       ` Marcelo Tosatti
2006-01-19 20:02         ` Nick Piggin
2006-01-19 21:41           ` Marcelo Tosatti
2006-01-18 10:41 ` Nick Piggin [this message]
2006-01-18 16:38 ` [patch 0/4] mm: de-skew page refcount Linus Torvalds
2006-01-18 17:05   ` Nick Piggin
2006-01-18 19:27     ` Linus Torvalds
2006-01-19 14:00       ` Nick Piggin
2006-01-19 16:36         ` Linus Torvalds
2006-01-19 17:06           ` Nick Piggin
2006-01-19 17:27             ` Linus Torvalds
2006-01-19 17:38               ` Nick Piggin
  -- strict thread matches above, loose matches on Subject: below --
2006-01-08  5:23 [patch 0/4] mm: de-skew page_count Nick Piggin
2006-01-08  5:25 ` [patch 4/4] mm: less atomic ops Nick Piggin
2005-12-05 11:59 [patch 0/4] mm: optimisations Nick Piggin
2005-12-05 12:01 ` [patch 4/4] mm: less atomic ops Nick Piggin

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