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 <mgor...@suse.de>
---
include/linux/mm.h | 30 ++++++++++++++++++++++++++++++
include/linux/mm_types.h | 4 ++++
mm/page_alloc.c | 2 ++
3 files changed, 36 insertions(+)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 34f8ce9..f290cc9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -693,6 +693,36 @@ static inline int page_to_nid(const struct page *page)
}
#endif
+#ifdef CONFIG_BALANCE_NUMA
+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)];
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index b40f4ef..6b478ff 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -175,6 +175,10 @@ struct page {
*/
void *shadow;
#endif
+
+#ifdef CONFIG_BALANCE_NUMA
+ int _last_nid;
+#endif
}
/*
* The struct page can be forced to be double word aligned so that atomic ops
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8827523..cc1ca7e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -608,6 +608,7 @@ static inline int free_pages_check(struct page *page)
bad_page(page);
return 1;
}
+ reset_page_last_nid(page);
if (page->flags & PAGE_FLAGS_CHECK_AT_PREP)
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
return 0;
@@ -3826,6 +3827,7 @@ void __meminit memmap_init_zone(unsigned long size, int
nid, unsigned long zone,
mminit_verify_page_links(page, zone, nid, pfn);
init_page_count(page);
reset_page_mapcount(page);
+ reset_page_last_nid(page);
SetPageReserved(page);
/*
* Mark the block movable so that blocks are reserved for
--
1.7.9.2
--
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