From e3b4126c556ca3a07699adf202d44bed3f453638 Mon Sep 17 00:00:00 2001
From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Date: Mon, 8 Oct 2012 16:32:57 -0700
Subject: [PATCH] thp: khugepaged_prealloc_page() forgot to reset the page
 alloc indicator

If NUMA is enabled, the indicator is not reset if the previous page
request failed, ausing us to trigger the BUG_ON() in
khugepaged_alloc_page().

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/huge_memory.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7cf8b0e..7153e0d1 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1797,6 +1797,7 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
 			return false;
 
 		*wait = false;
+		*hpage = NULL;
 		khugepaged_alloc_sleep();
 	} else if (*hpage) {
 		put_page(*hpage);
-- 
2.7.4