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>

1 files changed, 1 insertions, 0 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7cf8b0ec11ec..7153e0d18670 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);