[PATCH v3 06/13] pagemap: use walk->vma instead of calling find_vma()

Naoya Horiguchi
2014-06-20T20:12:22Z

Page table walker has the information of the current vma in mm_walk, so
we don't have to call find_vma() in each pagemap_hugetlb_range() call.

NULL-vma check is omitted because we assume that we never run hugetlb_entry()
callback on the address without vma. And even if it were broken, null pointer
dereference would be detected, so we can get enough information for debugging.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
---
fs/proc/task_mmu.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git v3.16-rc1.orig/fs/proc/task_mmu.c v3.16-rc1/fs/proc/task_mmu.c
index 3c42cd40ad36..74f87794afab 100644
--- v3.16-rc1.orig/fs/proc/task_mmu.c
+++ v3.16-rc1/fs/proc/task_mmu.c
@@ -1082,15 +1082,12 @@ static int pagemap_hugetlb_range(pte_t *pte, unsigned long hmask,
struct mm_walk *walk)
{
struct pagemapread *pm = walk->private;
- struct vm_area_struct *vma;
+ struct vm_area_struct *vma = walk->vma;
int err = 0;
int flags2;
pagemap_entry_t pme;

- vma = find_vma(walk->mm, addr);
- WARN_ON_ONCE(!vma);
-
- if (vma && (vma->vm_flags & VM_SOFTDIRTY))
+ if (vma->vm_flags & VM_SOFTDIRTY)
flags2 = __PM_SOFT_DIRTY;
else
flags2 = 0;
--
1.9.3