Re: [PATCH v4 05/13] clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()

Naoya Horiguchi
2014-07-10T13:28:17Z

On Thu, Jul 10, 2014 at 02:32:19PM +0300, Kirill A. Shutemov wrote:
> On Tue, Jul 01, 2014 at 01:07:23PM -0400, Naoya Horiguchi wrote:
> > @@ -822,38 +844,14 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
> > };
> > struct mm_walk clear_refs_walk = {
> > .pmd_entry = clear_refs_pte_range,
> > + .test_walk = clear_refs_test_walk,
> > .mm = mm,
> > .private = &cp,
> > };
> > down_read(&mm->mmap_sem);
> > if (type == CLEAR_REFS_SOFT_DIRTY)
> > mmu_notifier_invalidate_range_start(mm, 0, -1);
> > - for (vma = mm->mmap; vma; vma = vma->vm_next) {
> > - cp.vma = vma;
> > - if (is_vm_hugetlb_page(vma))
> > - continue;
> > - /*
> > - * Writing 1 to /proc/pid/clear_refs affects all pages.
> > - *
> > - * Writing 2 to /proc/pid/clear_refs only affects
> > - * Anonymous pages.
> > - *
> > - * Writing 3 to /proc/pid/clear_refs only affects file
> > - * mapped pages.
> > - *
> > - * Writing 4 to /proc/pid/clear_refs affects all pages.
> > - */
> > - if (type == CLEAR_REFS_ANON && vma->vm_file)
> > - continue;
> > - if (type == CLEAR_REFS_MAPPED && !vma->vm_file)
> > - continue;
> > - if (type == CLEAR_REFS_SOFT_DIRTY) {
> > - if (vma->vm_flags & VM_SOFTDIRTY)
> > - vma->vm_flags &= ~VM_SOFTDIRTY;
> > - }
> > - walk_page_range(vma->vm_start, vma->vm_end,
> > - &clear_refs_walk);
> > - }
> > + walk_page_range(0, ~0UL, &clear_refs_walk);
>
> 'vma' variable is now unused in the clear_refs_write().

Yes, will remove it.

Naoya