On Thu, Nov 05, 2015 at 03:07:26PM +0300, Vladimir Davydov wrote:
> @@ -849,30 +836,23 @@ static int page_referenced_one(struct page *page, struct vm_area_struct *vma,
> if (pmd_page(*pmd) != page)
> goto unlock_pmd;
>
> - if (vma->vm_flags & VM_LOCKED) {
> - pra->vm_flags |= VM_LOCKED;
> - ret = SWAP_FAIL; /* To break the loop */
> - goto unlock_pmd;
> - }
> -
> - if (pmdp_clear_flush_young_notify(vma, address, pmd))
> - referenced++;
> - spin_unlock(ptl);
> + pte = (pte_t *)pmd;
pmd_t and pte_t are not always compatible. We shouldn't pretend they are.
And we shouldn't use pte_unmap_unlock() to unlock pmd table.
What about interface like this (I'm not sure about helper's name):
void page_check_address_transhuge(struct page *page, struct mm_struct *mm,
unsigned long address,
pmd_t **pmdp, pte_t **ptep,
spinlock_t **ptlp);
page_check_address_transhuge(page, mm, address, &pmd, &pte, &ptl);
if (pmd) {
/* handle pmd... */
} else if (pte) {
/* handle pte... */
} else {
return SWAP_AGAIN;
}
/* common stuff */
if (pmd)
spin_unlock(ptl);
else
pte_unmap_unlock(pte, ptl);
/* ... */
The helper shouldn't set pmd if the page is tracked to pte.
--
Kirill A. Shutemov
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