[PATCH] reduce MAX_NR_ZONES: make ZONE_HIGHMEM optional
Make ZONE_HIGHMEM optional
- ifdef out code and definitions related to CONFIG_HIGHMEM
- __GFP_HIGHMEM falls back to normal allocations if there is no
ZONE_HIGHMEM
- GFP_ZONEMASK becomes 0x01 if there is no DMA32 and no HIGHMEM
zone.
[jdike@addtoit.com: build fix]
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index adae3c9..76d33e6 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -123,6 +123,7 @@
* transfers to all addressable memory.
*/
ZONE_NORMAL,
+#ifdef CONFIG_HIGHMEM
/*
* A memory area that is only addressable by the kernel through
* mapping portions into its own address space. This is for example
@@ -132,11 +133,10 @@
* access.
*/
ZONE_HIGHMEM,
-
+#endif
MAX_NR_ZONES
};
-#define ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */
/*
* When a memory allocation must conform to specific limitations (such
@@ -163,12 +163,34 @@
*
* NOTE! Make sure this matches the zones in <linux/gfp.h>
*/
-#define GFP_ZONETYPES ((GFP_ZONEMASK + 1) / 2 + 1) /* Loner */
#ifdef CONFIG_ZONE_DMA32
+
+#ifdef CONFIG_HIGHMEM
+#define GFP_ZONETYPES ((GFP_ZONEMASK + 1) / 2 + 1) /* Loner */
#define GFP_ZONEMASK 0x07
+#define ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */
#else
+#define GFP_ZONETYPES ((0x07 + 1) / 2 + 1) /* Loner */
+/* Mask __GFP_HIGHMEM */
+#define GFP_ZONEMASK 0x05
+#define ZONES_SHIFT 2
+#endif
+
+#else
+#ifdef CONFIG_HIGHMEM
+
#define GFP_ZONEMASK 0x03
+#define ZONES_SHIFT 2
+#define GFP_ZONETYPES 3
+
+#else
+
+#define GFP_ZONEMASK 0x01
+#define ZONES_SHIFT 1
+#define GFP_ZONETYPES 2
+
+#endif
#endif
struct zone {
@@ -409,7 +431,11 @@
static inline int is_highmem_idx(enum zone_type idx)
{
+#ifdef CONFIG_HIGHMEM
return (idx == ZONE_HIGHMEM);
+#else
+ return 0;
+#endif
}
static inline int is_normal_idx(enum zone_type idx)
@@ -425,7 +451,11 @@
*/
static inline int is_highmem(struct zone *zone)
{
+#ifdef CONFIG_HIGHMEM
return zone == zone->zone_pgdat->node_zones + ZONE_HIGHMEM;
+#else
+ return 0;
+#endif
}
static inline int is_normal(struct zone *zone)
