3.8.13.16 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: Mel Gorman <[email protected]>

commit 5a6dac3ec5f583cc8ee7bc53b5500a207c4ca433 upstream.

If the PMD is flushed then a parallel fault in handle_mm_fault() will
enter the pmd_none and do_huge_pmd_anonymous_page() path where it'll
attempt to insert a huge zero page.  This is wasteful so the patch
avoids clearing the PMD when setting pmd_numa.

Signed-off-by: Mel Gorman <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Cc: Alex Thorlton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
---
 mm/huge_memory.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a72d5ca..5d7dc7c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1506,7 +1506,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t 
*pmd,
                        /* only check non-shared pages */
                        if (page_mapcount(page) == 1 &&
                            !pmd_numa(*pmd)) {
-                               entry = pmdp_get_and_clear(mm, addr, pmd);
+                               entry = *pmd;
                                entry = pmd_mknuma(entry);
                                ret = HPAGE_PMD_NR;
                        }
-- 
1.8.3.2

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