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>
diff --git a/mm/page_idle.c b/mm/page_idle.c
index ae11aa9..b0ee56c 100644
--- a/mm/page_idle.c
+++ b/mm/page_idle.c
@@ -54,27 +54,27 @@
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);
/*