[PATCH 3.8 091/166] mm: numa: clear numa hinting information on mprotect

Kamal Mostafa
2014-01-15T21:51:45Z

From: Mel Gorman <mgorman@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@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Kamal Mostafa <kamal@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 594b3c1..a67726d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1504,6 +1504,8 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
ret = 1;
if (!prot_numa) {
entry = pmdp_get_and_clear(mm, addr, pmd);
+ if (pmd_numa(entry))
+ entry = pmd_mknonnuma(entry);
entry = pmd_modify(entry, newprot);
ret = HPAGE_PMD_NR;
BUG_ON(pmd_write(entry));
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 79abf13..c477655 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