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 028def32e48f94646d81d6454d0188d4a2f9cdf9..452e44fdea710ef33533546ed70b07ec7f902c20 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1866,6 +1866,7 @@ 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);