mm: Account for a THP NUMA hinting update as one PTE update
authorMel Gorman <mgorman@suse.de>
Mon, 7 Oct 2013 10:28:47 +0000 (11:28 +0100)
committerIngo Molnar <mingo@kernel.org>
Wed, 9 Oct 2013 10:39:46 +0000 (12:39 +0200)
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.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-10-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
mm/mprotect.c

index 94722a4..2bbb648 100644 (file)
@@ -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 */