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-rw-r--r--include/linux/mm.h53
-rw-r--r--include/linux/mmzone.h19
-rw-r--r--mm/page_alloc.c2
3 files changed, 52 insertions, 22 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1813b162b0a..57b2ead51db 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -395,19 +395,41 @@ static inline void put_page(struct page *page)
/*
* The zone field is never updated after free_area_init_core()
* sets it, so none of the operations on it need to be atomic.
- * We'll have up to (MAX_NUMNODES * MAX_NR_ZONES) zones total,
- * so we use (MAX_NODES_SHIFT + MAX_ZONES_SHIFT) here to get enough bits.
*/
-#define NODEZONE_SHIFT (sizeof(page_flags_t)*8 - MAX_NODES_SHIFT - MAX_ZONES_SHIFT)
+
+/* Page flags: | NODE | ZONE | ... | FLAGS | */
+#define NODES_PGOFF ((sizeof(page_flags_t)*8) - NODES_SHIFT)
+#define ZONES_PGOFF (NODES_PGOFF - ZONES_SHIFT)
+
+/*
+ * Define the bit shifts to access each section. For non-existant
+ * sections we define the shift as 0; that plus a 0 mask ensures
+ * the compiler will optimise away reference to them.
+ */
+#define NODES_PGSHIFT (NODES_PGOFF * (NODES_SHIFT != 0))
+#define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_SHIFT != 0))
+
+/* NODE:ZONE is used to lookup the zone from a page. */
+#define ZONETABLE_SHIFT (NODES_SHIFT + ZONES_SHIFT)
+#define ZONETABLE_PGSHIFT ZONES_PGSHIFT
+
+#if NODES_SHIFT+ZONES_SHIFT > FLAGS_RESERVED
+#error NODES_SHIFT+ZONES_SHIFT > FLAGS_RESERVED
+#endif
+
#define NODEZONE(node, zone) ((node << ZONES_SHIFT) | zone)
+#define ZONES_MASK ((1UL << ZONES_SHIFT) - 1)
+#define NODES_MASK ((1UL << NODES_SHIFT) - 1)
+#define ZONETABLE_MASK ((1UL << ZONETABLE_SHIFT) - 1)
+
static inline unsigned long page_zonenum(struct page *page)
{
- return (page->flags >> NODEZONE_SHIFT) & (~(~0UL << ZONES_SHIFT));
+ return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
}
static inline unsigned long page_to_nid(struct page *page)
{
- return (page->flags >> (NODEZONE_SHIFT + ZONES_SHIFT));
+ return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
}
struct zone;
@@ -415,13 +437,26 @@ extern struct zone *zone_table[];
static inline struct zone *page_zone(struct page *page)
{
- return zone_table[page->flags >> NODEZONE_SHIFT];
+ return zone_table[(page->flags >> ZONETABLE_PGSHIFT) &
+ ZONETABLE_MASK];
+}
+
+static inline void set_page_zone(struct page *page, unsigned long zone)
+{
+ page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
+ page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
+}
+static inline void set_page_node(struct page *page, unsigned long node)
+{
+ page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
+ page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
}
-static inline void set_page_zone(struct page *page, unsigned long nodezone_num)
+static inline void set_page_links(struct page *page, unsigned long zone,
+ unsigned long node)
{
- page->flags &= ~(~0UL << NODEZONE_SHIFT);
- page->flags |= nodezone_num << NODEZONE_SHIFT;
+ set_page_zone(page, zone);
+ set_page_node(page, node);
}
#ifndef CONFIG_DISCONTIGMEM
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index b79633d3a97..39e912708e2 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -414,30 +414,25 @@ extern struct pglist_data contig_page_data;
#include <asm/mmzone.h>
+#endif /* !CONFIG_DISCONTIGMEM */
+
#if BITS_PER_LONG == 32 || defined(ARCH_HAS_ATOMIC_UNSIGNED)
/*
* with 32 bit page->flags field, we reserve 8 bits for node/zone info.
* there are 3 zones (2 bits) and this leaves 8-2=6 bits for nodes.
*/
-#define MAX_NODES_SHIFT 6
+#define FLAGS_RESERVED 8
+
#elif BITS_PER_LONG == 64
/*
* with 64 bit flags field, there's plenty of room.
*/
-#define MAX_NODES_SHIFT 10
-#endif
+#define FLAGS_RESERVED 32
-#endif /* !CONFIG_DISCONTIGMEM */
-
-#if NODES_SHIFT > MAX_NODES_SHIFT
-#error NODES_SHIFT > MAX_NODES_SHIFT
-#endif
+#else
-/* There are currently 3 zones: DMA, Normal & Highmem, thus we need 2 bits */
-#define MAX_ZONES_SHIFT 2
+#error BITS_PER_LONG not defined
-#if ZONES_SHIFT > MAX_ZONES_SHIFT
-#error ZONES_SHIFT > MAX_ZONES_SHIFT
#endif
#endif /* !__ASSEMBLY__ */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bf1dd881909..1958358e29b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1653,7 +1653,7 @@ void __init memmap_init_zone(unsigned long size, int nid, unsigned long zone,
struct page *page;
for (page = start; page < (start + size); page++) {
- set_page_zone(page, NODEZONE(nid, zone));
+ set_page_links(page, zone, nid);
set_page_count(page, 0);
reset_page_mapcount(page);
SetPageReserved(page);