[PATCH] pagemap: fix order of pmd_trans_unstable() and pmd_trans_huge_lock()

Naoya Horiguchi
2012-03-29T09:26:43Z

pmd_trans_unstable() in pagemap_pte_range() comes before pmd_trans_huge_lock()
now, which means that pagewalk kicked by reading /proc/pid/pagemap does not
run over thp. This patch fixes it.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
---
fs/proc/task_mmu.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git linux-3.3.0-6658a6991ce.orig/fs/proc/task_mmu.c linux-3.3.0-6658a6991ce/fs/proc/task_mmu.c
index 06d2b70..0105ba1 100644
--- linux-3.3.0-6658a6991ce.orig/fs/proc/task_mmu.c
+++ linux-3.3.0-6658a6991ce/fs/proc/task_mmu.c
@@ -781,9 +781,6 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
int err = 0;
pagemap_entry_t pme = make_pme(PM_NOT_PRESENT);

- if (pmd_trans_unstable(pmd))
- return 0;
-
/* find the first VMA at or above 'addr' */
vma = find_vma(walk->mm, addr);
if (pmd_trans_huge_lock(pmd, vma) == 1) {
@@ -801,6 +798,9 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
return err;
}

+ if (pmd_trans_unstable(pmd))
+ return 0;
+
for (; addr != end; addr += PAGE_SIZE) {

/* check to see if we've left 'vma' behind
--
1.7.7.6