From: jbarnes@sgi.com (Jesse Barnes)
Now that we have a proper NODES_SHIFT value, we need to use it to define
ZONE_SHIFT otherwise we'll spill over 8 bits if we have more than 85 nodes.
25-akpm/include/linux/mm.h | 4 +++-
25-akpm/include/linux/mmzone.h | 5 ++++-
2 files changed, 7 insertions(+), 2 deletions(-)
diff -puN include/linux/mm.h~ZONE_SHIFT-from-NODES_SHIFT include/linux/mm.h
--- 25/include/linux/mm.h~ZONE_SHIFT-from-NODES_SHIFT Fri Nov 7 13:51:22 2003
+++ 25-akpm/include/linux/mm.h Fri Nov 7 13:55:11 2003
@@ -322,8 +322,10 @@ static inline void put_page(struct 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 log2(MAX_NUMNODES * MAX_NR_ZONES) zones
+ * total, so we use NODES_SHIFT here to get enough bits.
*/
-#define ZONE_SHIFT (BITS_PER_LONG - 8)
+#define ZONE_SHIFT (BITS_PER_LONG - NODES_SHIFT - MAX_NR_ZONES_SHIFT)
struct zone;
extern struct zone *zone_table[];
diff -puN include/linux/mmzone.h~ZONE_SHIFT-from-NODES_SHIFT include/linux/mmzone.h
--- 25/include/linux/mmzone.h~ZONE_SHIFT-from-NODES_SHIFT Fri Nov 7 13:51:49 2003
+++ 25-akpm/include/linux/mmzone.h Fri Nov 7 13:57:19 2003
@@ -159,7 +159,10 @@ struct zone {
#define ZONE_DMA 0
#define ZONE_NORMAL 1
#define ZONE_HIGHMEM 2
-#define MAX_NR_ZONES 3
+
+#define MAX_NR_ZONES 3 /* Sync this with MAX_NR_ZONES_SHIFT */
+#define MAX_NR_ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */
+
#define GFP_ZONEMASK 0x03
/*
_