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.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
---
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 deae592..5a5da50 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1529,7 +1529,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
*/
if (!is_huge_zero_page(page) &&
!pmd_numa(*pmd)) {
- entry = pmdp_get_and_clear(mm, addr, pmd);
+ entry = *pmd;
entry = pmd_mknuma(entry);
ret = HPAGE_PMD_NR;
}
--
1.8.4
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