From 28bd65781c848d95ba6a7f58b5c4b8265a804ec6 Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan.kim@gmail.com>
Date: Tue, 25 Jan 2011 15:07:26 -0800
Subject: [PATCH] mm: migration: clarify migrate_pages() comment

Callers of migrate_pages should putback_lru_pages to return pages
isolated to LRU or free list.  Now comment is rather confusing.  It says
caller always have to call it.

It is more clear to point out that the caller has to call it if
migrate_pages's return value isn't zero.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/migrate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 46fe8cc13d67f3..9f29a3b7aac224 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -888,7 +888,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
  * are movable anymore because to has become empty
  * or no retryable pages exist anymore.
  * Caller should call putback_lru_pages to return pages to the LRU
- * or free list.
+ * or free list only if ret != 0.
  *
  * Return: Number of pages not migrated or error code.
  */