mm: fix handling PTE-mapped THPs in page_idle_clear_pte_refs()

For PTE-mapped THP page_check_address_transhuge() is not adequate: it
cannot find all relevant PTEs, only the first one.i

Let's switch it to page_vma_mapped_walk().

I don't think it's subject for stable@: it's not fatal.

Link: http://lkml.kernel.org/r/20170129173858.45174-5-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov 2017-02-24 14:57:51 -08:00 committed by Linus Torvalds
parent 8eaedede82
commit 699fa21680

View file

@ -54,27 +54,27 @@ static int page_idle_clear_pte_refs_one(struct page *page,
struct vm_area_struct *vma,
unsigned long addr, void *arg)
{
struct mm_struct *mm = vma->vm_mm;
pmd_t *pmd;
pte_t *pte;
spinlock_t *ptl;
struct page_vma_mapped_walk pvmw = {
.page = page,
.vma = vma,
.address = addr,
};
bool referenced = false;
if (!page_check_address_transhuge(page, mm, addr, &pmd, &pte, &ptl))
return SWAP_AGAIN;
if (pte) {
referenced = ptep_clear_young_notify(vma, addr, pte);
pte_unmap(pte);
} else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
referenced = pmdp_clear_young_notify(vma, addr, pmd);
} else {
/* unexpected pmd-mapped page? */
WARN_ON_ONCE(1);
while (page_vma_mapped_walk(&pvmw)) {
addr = pvmw.address;
if (pvmw.pte) {
referenced = ptep_clear_young_notify(vma, addr,
pvmw.pte);
} else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
referenced = pmdp_clear_young_notify(vma, addr,
pvmw.pmd);
} else {
/* unexpected pmd-mapped page? */
WARN_ON_ONCE(1);
}
}
spin_unlock(ptl);
if (referenced) {
clear_page_idle(page);
/*