[PATCH 1/2] mm: thp: Return the correct value for change_huge_pmd
From: Mel Gorman <mgorman@suse.de>
Date: 2015-03-05 23:55:04
Also in:
linux-mm, linux-xfs, lkml
Subsystem:
memory management, memory management - thp (transparent huge page), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds
The wrong value is being returned by change_huge_pmd since commit
10c1045f28e8 ("mm: numa: avoid unnecessary TLB flushes when setting
NUMA hinting entries") which allows a fallthrough that tries to adjust
non-existent PTEs. This patch corrects it.
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
mm/huge_memory.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index fc00c8cb5a82..194c0f019774 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c@@ -1482,6 +1482,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { pmd_t entry; + ret = 1; /* * Avoid trapping faults against the zero page. The read-only
@@ -1490,11 +1491,10 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, */ if (prot_numa && is_huge_zero_pmd(*pmd)) { spin_unlock(ptl); - return 0; + return ret; } if (!prot_numa || !pmd_protnone(*pmd)) { - ret = 1; entry = pmdp_get_and_clear_notify(mm, addr, pmd); entry = pmd_modify(entry, newprot); ret = HPAGE_PMD_NR;
--
2.1.2