mm: numa: Introduce last_nid to the page frame
This patch introduces a last_nid field to the page struct. This is used
to build a two-stage filter in the next patch that is aimed at
mitigating a problem whereby pages migrate to the wrong node when
referenced by a process that was running off its home node.
Signed-off-by: Mel Gorman <mgorman@suse.de>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d04c2f0..d87f9ec 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -693,6 +693,36 @@
}
#endif
+#ifdef CONFIG_NUMA_BALANCING
+static inline int page_xchg_last_nid(struct page *page, int nid)
+{
+ return xchg(&page->_last_nid, nid);
+}
+
+static inline int page_last_nid(struct page *page)
+{
+ return page->_last_nid;
+}
+static inline void reset_page_last_nid(struct page *page)
+{
+ page->_last_nid = -1;
+}
+#else
+static inline int page_xchg_last_nid(struct page *page, int nid)
+{
+ return page_to_nid(page);
+}
+
+static inline int page_last_nid(struct page *page)
+{
+ return page_to_nid(page);
+}
+
+static inline void reset_page_last_nid(struct page *page)
+{
+}
+#endif
+
static inline struct zone *page_zone(const struct page *page)
{
return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];