summary refs log tree commit diff
path: root/mm/huge_memory.c
diff options
context:
space:
mode:
authorMel Gorman <mgorman@suse.de>2013-12-18 17:08:36 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-12-18 19:04:51 -0800
commit5a6dac3ec5f583cc8ee7bc53b5500a207c4ca433 (patch)
tree471c00fcd2c7666cdf91132c6557efb34264ace6 /mm/huge_memory.c
parent67f87463d3a3362424efcbe8b40e4772fd34fc61 (diff)
downloadlinux-5a6dac3ec5f583cc8ee7bc53b5500a207c4ca433.tar.gz
mm: numa: do not clear PMD during PTE update scan
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 <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
-rw-r--r--mm/huge_memory.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 51f069303ab9..420826efda48 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1539,7 +1539,7 @@ 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;
 			}