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

Kirill A. Shutemov
2014-07-10T11:32:40Z

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().

--
Kirill A. Shutemov