[PATCH 09/63] mm: Account for a THP NUMA hinting update as one PTE update

From: Mel Gorman
Date: Mon Oct 07 2013 - 06:41:31 EST


A THP PMD update is accounted for as 512 pages updated in vmstat. This is
large difference when estimating the cost of automatic NUMA balancing and
can be misleading when comparing results that had collapsed versus split
THP. This patch addresses the accounting issue.

Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
---
mm/mprotect.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 94722a4..2bbb648 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -145,7 +145,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
split_huge_page_pmd(vma, addr, pmd);
else if (change_huge_pmd(vma, pmd, addr, newprot,
prot_numa)) {
- pages += HPAGE_PMD_NR;
+ pages++;
continue;
}
/* fall through */
--
1.8.4

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