[3.8.y.z extended stable] Patch "mm: Account for a THP NUMA hinting update as one PTE update" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    mm: Account for a THP NUMA hinting update as one PTE update

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.13.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 27b2d5c54874bc04c15ba6c1a59a643774cd6961 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman at suse.de>
Date: Mon, 7 Oct 2013 11:28:47 +0100
Subject: mm: Account for a THP NUMA hinting update as one PTE update

commit 0255d491848032f6c601b6410c3b8ebded3a37b1 upstream.

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 at suse.de>
Reviewed-by: Rik van Riel <riel at redhat.com>
Cc: Andrea Arcangeli <aarcange at redhat.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Srikar Dronamraju <srikar at linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz at infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-10-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 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 */
--
1.8.1.2