[PATCH] numa: fix /proc/<pid>/numa_maps on s390

From: Michael Holzheu
Date: Wed Jan 20 2016 - 13:18:15 EST


When working with huge page pmds in general is not valid to directly
use pte functions like pte_present() because the hardware bit layout
of pmds and ptes can be different. This is the case on s390. Therefore
we have to convert the pmds first into a valid pte encoding with
huge_ptep_get(). So add the two missing functions calls to do this.

Reviewed-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
Signed-off-by: Michael Holzheu <holzheu@xxxxxxxxxxxxxxxxxx>
---
fs/proc/task_mmu.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 65a1b6c..e287e32 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1520,7 +1520,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
pte_t *pte;

if (pmd_trans_huge_lock(pmd, vma, &ptl)) {
- pte_t huge_pte = *(pte_t *)pmd;
+ pte_t huge_pte = huge_ptep_get((pte_t *)pmd);
struct page *page;

page = can_gather_numa_stats(huge_pte, vma, addr);
@@ -1548,18 +1548,19 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
unsigned long addr, unsigned long end, struct mm_walk *walk)
{
+ pte_t huge_pte = huge_ptep_get(pte);
struct numa_maps *md;
struct page *page;

- if (!pte_present(*pte))
+ if (!pte_present(huge_pte))
return 0;

- page = pte_page(*pte);
+ page = pte_page(huge_pte);
if (!page)
return 0;

md = walk->private;
- gather_stats(page, md, pte_dirty(*pte), 1);
+ gather_stats(page, md, pte_dirty(huge_pte), 1);
return 0;
}

--
2.3.9