mm: memcg/slab: cache page number in memcg_(un)charge_slab()

[linux-2.6-microblaze.git] / mm / internal.h

diff --git a/mm/internal.h b/mm/internal.h
index 3cf20ab..91d1d38 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -63,6 +63,29 @@ static inline unsigned long ra_submit(struct file_ra_state *ra,
                                        ra->start, ra->size, ra->async_size);
 }
 
+/**
+ * page_evictable - test whether a page is evictable
+ * @page: the page to test
+ *
+ * Test whether page is evictable--i.e., should be placed on active/inactive
+ * lists vs unevictable list.
+ *
+ * Reasons page might not be evictable:
+ * (1) page's mapping marked unevictable
+ * (2) page is part of an mlocked VMA
+ *
+ */
+static inline bool page_evictable(struct page *page)
+{
+       bool ret;
+
+       /* Prevent address_space of inode and swap cache from being freed */
+       rcu_read_lock();
+       ret = !mapping_unevictable(page_mapping(page)) && !PageMlocked(page);
+       rcu_read_unlock();
+       return ret;
+}
+
 /*
  * Turn a non-refcounted page (->_refcount == 0) into refcounted with
  * a count of one.