From 053837fce7aa79025ed57656855df09f80175527 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@suse.de>
Date: Wed, 18 Jan 2006 17:42:27 -0800
Subject: [PATCH] mm: migration page refcounting fix

Migration code currently does not take a reference to target page
properly, so between unlocking the pte and trying to take a new
reference to the page with isolate_lru_page, anything could happen to
it.

Fix this by holding the pte lock until we get a chance to elevate the
refcount.

Other small cleanups while we're here.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 mm/rmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'mm/rmap.c')

diff --git a/mm/rmap.c b/mm/rmap.c
index dfbb89f99a15..d85a99d28c03 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -33,7 +33,7 @@
  *     mapping->i_mmap_lock
  *       anon_vma->lock
  *         mm->page_table_lock or pte_lock
- *           zone->lru_lock (in mark_page_accessed)
+ *           zone->lru_lock (in mark_page_accessed, isolate_lru_page)
  *           swap_lock (in swap_duplicate, swap_info_get)
  *             mmlist_lock (in mmput, drain_mmlist and others)
  *             mapping->private_lock (in __set_page_dirty_buffers)
-- 
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