struct zone *zone = page_zone(page);
spin_lock_irq(&zone->lru_lock);
- if (PageLRU(page)) {
+ if (PageLRU(page) && get_page_unless_zero(page)) {
ret = 0;
- get_page(page);
ClearPageLRU(page);
if (PageActive(page))
del_page_from_active_list(zone, page);
void **pslot;
if (!mapping) {
- /* Anonymous page */
+ /* Anonymous page without mapping */
if (page_count(page) != 1)
return -EAGAIN;
return 0;
*/
__put_page(page);
+ /*
+ * If moved to a different zone then also account
+ * the page for that zone. Other VM counters will be
+ * taken care of when we establish references to the
+ * new page and drop references to the old page.
+ *
+ * Note that anonymous pages are accounted for
+ * via NR_FILE_PAGES and NR_ANON_PAGES if they
+ * are mapped to swap space.
+ */
+ __dec_zone_page_state(page, NR_FILE_PAGES);
+ __inc_zone_page_state(newpage, NR_FILE_PAGES);
+
write_unlock_irq(&mapping->tree_lock);
return 0;
goto unlock;
wait_on_page_writeback(page);
}
-
/*
- * Establish migration ptes or remove ptes
+ * By try_to_unmap(), page->mapcount goes down to 0 here. In this case,
+ * we cannot notice that anon_vma is freed while we migrates a page.
+ * This rcu_read_lock() delays freeing anon_vma pointer until the end
+ * of migration. File cache pages are no problem because of page_lock()
*/
+ rcu_read_lock();
+ /*
+ * This is a corner case handling.
+ * When a new swap-cache is read into, it is linked to LRU
+ * and treated as swapcache but has no rmap yet.
+ * Calling try_to_unmap() against a page->mapping==NULL page is
+ * BUG. So handle it here.
+ */
+ if (!page->mapping)
+ goto rcu_unlock;
+ /* Establish migration ptes or remove ptes */
try_to_unmap(page, 1);
+
if (!page_mapped(page))
rc = move_to_new_page(newpage, page);
if (rc)
remove_migration_ptes(page, page);
+rcu_unlock:
+ rcu_read_unlock();
unlock:
+
unlock_page(page);
if (rc != -EAGAIN) {
*result = &pm->status;
- return alloc_pages_node(pm->node, GFP_HIGHUSER | GFP_THISNODE, 0);
+ return alloc_pages_node(pm->node,
+ GFP_HIGHUSER_MOVABLE | GFP_THISNODE, 0);
}
/*
err = -EFAULT;
vma = find_vma(mm, pp->addr);
- if (!vma)
+ if (!vma || !vma_migratable(vma))
goto set_status;
page = follow_page(vma, pp->addr, FOLL_GET);