[PATCH -mm v5 06/13] pagemap: use walk->vma instead of calling find_vma()

From: Naoya Horiguchi
Date: Fri Jul 11 2014 - 14:36:42 EST

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@xxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
fs/proc/task_mmu.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git mmotm-2014-07-09-17-08.orig/fs/proc/task_mmu.c mmotm-2014-07-09-17-08/fs/proc/task_mmu.c
index 4baf34230191..e4c6cdb9647b 100644
--- mmotm-2014-07-09-17-08.orig/fs/proc/task_mmu.c
+++ mmotm-2014-07-09-17-08/fs/proc/task_mmu.c
@@ -1073,15 +1073,12 @@ 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;
flags2 = 0;

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