mm: convert remove_migration_pte() to use page_vma_mapped_walk()
remove_migration_pte() also can easily be converted to
page_vma_mapped_walk().
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170129173858.45174-13-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.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>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/migrate.c b/mm/migrate.c
index 6807174..2c63ac0 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -193,82 +193,62 @@
/*
* Restore a potential migration pte to a working pte entry
*/
-static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
+static int remove_migration_pte(struct page *page, struct vm_area_struct *vma,
unsigned long addr, void *old)
{
- struct mm_struct *mm = vma->vm_mm;
+ struct page_vma_mapped_walk pvmw = {
+ .page = old,
+ .vma = vma,
+ .address = addr,
+ .flags = PVMW_SYNC | PVMW_MIGRATION,
+ };
+ struct page *new;
+ pte_t pte;
swp_entry_t entry;
- pmd_t *pmd;
- pte_t *ptep, pte;
- spinlock_t *ptl;
- if (unlikely(PageHuge(new))) {
- ptep = huge_pte_offset(mm, addr);
- if (!ptep)
- goto out;
- ptl = huge_pte_lockptr(hstate_vma(vma), mm, ptep);
- } else {
- pmd = mm_find_pmd(mm, addr);
- if (!pmd)
- goto out;
+ VM_BUG_ON_PAGE(PageTail(page), page);
+ while (page_vma_mapped_walk(&pvmw)) {
+ new = page - pvmw.page->index +
+ linear_page_index(vma, pvmw.address);
- ptep = pte_offset_map(pmd, addr);
+ get_page(new);
+ pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot)));
+ if (pte_swp_soft_dirty(*pvmw.pte))
+ pte = pte_mksoft_dirty(pte);
/*
- * Peek to check is_swap_pte() before taking ptlock? No, we
- * can race mremap's move_ptes(), which skips anon_vma lock.
+ * Recheck VMA as permissions can change since migration started
*/
-
- ptl = pte_lockptr(mm, pmd);
- }
-
- spin_lock(ptl);
- pte = *ptep;
- if (!is_swap_pte(pte))
- goto unlock;
-
- entry = pte_to_swp_entry(pte);
-
- if (!is_migration_entry(entry) ||
- migration_entry_to_page(entry) != old)
- goto unlock;
-
- get_page(new);
- pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot)));
- if (pte_swp_soft_dirty(*ptep))
- pte = pte_mksoft_dirty(pte);
-
- /* Recheck VMA as permissions can change since migration started */
- if (is_write_migration_entry(entry))
- pte = maybe_mkwrite(pte, vma);
+ entry = pte_to_swp_entry(*pvmw.pte);
+ if (is_write_migration_entry(entry))
+ pte = maybe_mkwrite(pte, vma);
#ifdef CONFIG_HUGETLB_PAGE
- if (PageHuge(new)) {
- pte = pte_mkhuge(pte);
- pte = arch_make_huge_pte(pte, vma, new, 0);
- }
+ if (PageHuge(new)) {
+ pte = pte_mkhuge(pte);
+ pte = arch_make_huge_pte(pte, vma, new, 0);
+ }
#endif
- flush_dcache_page(new);
- set_pte_at(mm, addr, ptep, pte);
+ flush_dcache_page(new);
+ set_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
- if (PageHuge(new)) {
- if (PageAnon(new))
- hugepage_add_anon_rmap(new, vma, addr);
+ if (PageHuge(new)) {
+ if (PageAnon(new))
+ hugepage_add_anon_rmap(new, vma, pvmw.address);
+ else
+ page_dup_rmap(new, true);
+ } else if (PageAnon(new))
+ page_add_anon_rmap(new, vma, pvmw.address, false);
else
- page_dup_rmap(new, true);
- } else if (PageAnon(new))
- page_add_anon_rmap(new, vma, addr, false);
- else
- page_add_file_rmap(new, false);
+ page_add_file_rmap(new, false);
- if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
- mlock_vma_page(new);
+ if (vma->vm_flags & VM_LOCKED && !PageTransCompound(new))
+ mlock_vma_page(new);
- /* No need to invalidate - it was non-present before */
- update_mmu_cache(vma, addr, ptep);
-unlock:
- pte_unmap_unlock(ptep, ptl);
-out:
+ /* No need to invalidate - it was non-present before */
+ update_mmu_cache(vma, pvmw.address, pvmw.pte);
+ }
+
return SWAP_AGAIN;
}