[PATCH 3.11 151/208] mm: numa: clear numa hinting information on mprotect

[Luis Henriques]

3.11.10.3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mel Gorman <mgorman at suse.de>

commit 1667918b6483b12a6496bf54151b827b8235d7b1 upstream.

On a protection change it is no longer clear if the page should be still
accessible.  This patch clears the NUMA hinting fault bits on a
protection change.

Signed-off-by: Mel Gorman <mgorman at suse.de>
Reviewed-by: Rik van Riel <riel at redhat.com>
Cc: Alex Thorlton <athorlton at sgi.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 mm/huge_memory.c | 2 ++
 mm/mprotect.c    | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0db1517..1385bf9 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1495,6 +1495,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 		pmd_t entry;
 		if (!prot_numa) {
 			entry = pmdp_get_and_clear(mm, addr, pmd);
+			if (pmd_numa(entry))
+				entry = pmd_mknonnuma(entry);
 			entry = pmd_modify(entry, newprot);
 			BUG_ON(pmd_write(entry));
 			set_pmd_at(mm, addr, pmd, entry);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 3277121..00edb75 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -56,6 +56,8 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 
 			if (!prot_numa) {
 				ptent = ptep_modify_prot_start(mm, addr, pte);
+				if (pte_numa(ptent))
+					ptent = pte_mknonnuma(ptent);
 				ptent = pte_modify(ptent, newprot);
 				updated = true;
 			} else {
-- 
1.8.3.2