[PATCH 09/18] mm: numa: Clear numa hinting information on mprotect

From: Mel Gorman
Date: Tue Dec 10 2013 - 10:54:53 EST


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.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
---
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 0f00b96..0ecaba2 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1522,6 +1522,8 @@ 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 0a07e2d..eb2f349 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -54,6 +54,8 @@ 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 {
--
1.8.4

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