mm: numa: do not trap faults on the huge zero page

Faults on the huge zero page are pointless and there is a BUG_ON to catch
them during fault time.  This patch reintroduces a check that avoids
marking the zero page PAGE_NONE.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/mm/memory.c b/mm/memory.c
index d7921760cf79..bf244f56b05a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3040,7 +3040,6 @@ static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 pte_unmap_unlock(ptep, ptl);
                 return 0;
         }
-        BUG_ON(is_zero_pfn(page_to_pfn(page)));
 
         /*
          * Avoid grouping on DSO/COW pages in specific and RO pages