Commit e53ef38d authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

[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: default avatarJeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarChristoph Lameter <clameter@engr.sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent fb0e7942
......@@ -226,7 +226,9 @@ void paging_init(void)
for(i=0;i<sizeof(zones_size)/sizeof(zones_size[0]);i++)
zones_size[i] = 0;
zones_size[ZONE_DMA] = (end_iomem >> PAGE_SHIFT) - (uml_physmem >> PAGE_SHIFT);
#ifdef CONFIG_HIGHMEM
zones_size[ZONE_HIGHMEM] = highmem >> PAGE_SHIFT;
#endif
free_area_init(zones_size);
/*
......
......@@ -9,17 +9,19 @@ struct vm_area_struct;
/*
* GFP bitmasks..
*
* Zone modifiers (see linux/mmzone.h - low three bits)
*
* These may be masked by GFP_ZONEMASK to make allocations with this bit
* set fall back to ZONE_NORMAL.
*
* Do not put any conditional on these. If necessary modify the definitions
* without the underscores and use the consistently. The definitions here may
* be used in bit comparisons.
*/
/* Zone modifiers in GFP_ZONEMASK (see linux/mmzone.h - low three bits) */
#define __GFP_DMA ((__force gfp_t)0x01u)
#define __GFP_HIGHMEM ((__force gfp_t)0x02u)
#ifndef CONFIG_ZONE_DMA32
#define __GFP_DMA32 ((__force gfp_t)0x01) /* ZONE_DMA is ZONE_DMA32 */
#elif BITS_PER_LONG < 64
#define __GFP_DMA32 ((__force gfp_t)0x00) /* ZONE_NORMAL is ZONE_DMA32 */
#else
#define __GFP_DMA32 ((__force gfp_t)0x04) /* Has own ZONE_DMA32 */
#endif
#define __GFP_DMA32 ((__force gfp_t)0x04u)
/*
* Action modifiers - doesn't change the zoning
......
......@@ -123,6 +123,7 @@ enum zone_type {
* 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 @@ enum zone_type {
* 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 @@ enum zone_type {
*
* 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 populated_zone(struct zone *zone)
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_normal_idx(enum zone_type idx)
*/
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)
......
......@@ -73,7 +73,9 @@ int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
#ifdef CONFIG_ZONE_DMA32
256,
#endif
#ifdef CONFIG_HIGHMEM
32
#endif
};
EXPORT_SYMBOL(totalram_pages);
......@@ -91,7 +93,9 @@ static char *zone_names[MAX_NR_ZONES] = {
"DMA32",
#endif
"Normal",
#ifdef CONFIG_HIGHMEM
"HighMem"
#endif
};
int min_free_kbytes = 1024;
......@@ -1375,8 +1379,10 @@ static int __meminit build_zonelists_node(pg_data_t *pgdat,
static inline int highest_zone(int zone_bits)
{
int res = ZONE_NORMAL;
#ifdef CONFIG_HIGHMEM
if (zone_bits & (__force int)__GFP_HIGHMEM)
res = ZONE_HIGHMEM;
#endif
#ifdef CONFIG_ZONE_DMA32
if (zone_bits & (__force int)__GFP_DMA32)
res = ZONE_DMA32;
......
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