mm: Account for a THP NUMA hinting update as one PTE update
[linux-3.10.git] / mm / mmzone.c
index 4596d81..2ac0afb 100644 (file)
@@ -1,7 +1,7 @@
 /*
  * linux/mm/mmzone.c
  *
- * management codes for pgdats and zones.
+ * management codes for pgdats, zones and page flags
  */
 
 
@@ -96,3 +96,21 @@ void lruvec_init(struct lruvec *lruvec)
        for_each_lru(lru)
                INIT_LIST_HEAD(&lruvec->lists[lru]);
 }
+
+#if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_NID_NOT_IN_PAGE_FLAGS)
+int page_nid_xchg_last(struct page *page, int nid)
+{
+       unsigned long old_flags, flags;
+       int last_nid;
+
+       do {
+               old_flags = flags = page->flags;
+               last_nid = page_nid_last(page);
+
+               flags &= ~(LAST_NID_MASK << LAST_NID_PGSHIFT);
+               flags |= (nid & LAST_NID_MASK) << LAST_NID_PGSHIFT;
+       } while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags));
+
+       return last_nid;
+}
+#endif