From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Date: Thu, 13 Sep 2012 01:01:01 +0000 (+1000)
Subject: thp: khugepaged_prealloc_page() forgot to reset the page alloc indicator
X-Git-Tag: next-20120913~4^2~116
X-Git-Url: https://git.kernelconcepts.de/?a=commitdiff_plain;h=07902801896fb71081224fb660b2de58a986b1b0;p=karo-tx-linux.git

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>
---

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1b327a42f9e6..d50d574cd67e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1822,6 +1822,7 @@ 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);