Re: [PATCH v3 09/13] memcg: apply walk_page_vma()

Kirill A. Shutemov
2014-06-30T12:20:31Z

On Fri, Jun 20, 2014 at 04:11:35PM -0400, Naoya Horiguchi wrote:
> pagewalk.c can handle vma in itself, so we don't have to pass vma via
> walk->private. And both of mem_cgroup_count_precharge() and
> mem_cgroup_move_charge() walk over all vmas (not interested in outside vma,)
> so using walk_page_vma() is preferable.
>
> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>

My first thought was to suggest walk_page_range(0, -1, &walk) instead
since we walk over all vmas. But walk_page_range() uses find_vma() on each
iteration, which is expensive.
Is there a reason why we cannot use vma->vm_next in walk_page_range()?

--
Kirill A. Shutemov