[PATCH 3/6] Optional ZONE_DMA in the VM

Christoph Lameter
2006-09-11T22:27:44Z

Make ZONE_DMA optional in core code.

- ifdef definitions for ZONE_DMA and related code following
the example for ZONE_DMA32 and ZONE_HIGHMEM.

- Without ZONE_DMA, ZONE_HIGHMEM and ZONE_DMA32 we get to a
ZONES_SHIFT of 0.

- Modify the VM statistics to work correctly without a DMA
zone.

- Modify slab to not create DMA slabs if there is no
ZONE_DMA.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.18-rc6-mm1/include/linux/mmzone.h
=================================--- linux-2.6.18-rc6-mm1.orig/include/linux/mmzone.h 2006-09-11 16:44:16.000000000 -0500
+++ linux-2.6.18-rc6-mm1/include/linux/mmzone.h 2006-09-11 16:45:01.863158377 -0500
@@ -90,6 +90,7 @@
#endif

enum zone_type {
+#ifdef CONFIG_ZONE_DMA
/*
* ZONE_DMA is used when there are devices that are not able
* to do DMA to all of addressable memory (ZONE_NORMAL). Then we
@@ -110,6 +111,7 @@
* <16M.
*/
ZONE_DMA,
+#endif
#ifdef CONFIG_ZONE_DMA32
/*
* x86_64 needs two ZONE_DMAs because it supports devices that are
@@ -147,7 +149,11 @@
*/

#if !defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_HIGHMEM)
+#if !defined(CONFIG_ZONE_DMA)
+#define ZONES_SHIFT 0
+#else
#define ZONES_SHIFT 1
+#endif
#else
#define ZONES_SHIFT 2
#endif
@@ -447,7 +453,11 @@

static inline int is_dma(struct zone *zone)
{
+#ifdef CONFIG_ZONE_DMA
return zone = zone->zone_pgdat->node_zones + ZONE_DMA;
+#else
+ return 0;
+#endif
}

/* These two functions are used to setup the per zone pages min values */
Index: linux-2.6.18-rc6-mm1/mm/page_alloc.c
=================================--- linux-2.6.18-rc6-mm1.orig/mm/page_alloc.c 2006-09-11 16:44:51.000000000 -0500
+++ linux-2.6.18-rc6-mm1/mm/page_alloc.c 2006-09-11 16:45:01.883667932 -0500
@@ -71,7 +71,9 @@
* don't need any ZONE_NORMAL reservation
*/
int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
+#ifdef CONFIG_ZONE_DMA
256,
+#endif
#ifdef CONFIG_ZONE_DMA32
256,
#endif
@@ -90,7 +92,9 @@
EXPORT_SYMBOL(zone_table);

static char *zone_names[MAX_NR_ZONES] = {
+#ifdef CONFIG_ZONE_DMA
"DMA",
+#endif
#ifdef CONFIG_ZONE_DMA32
"DMA32",
#endif
Index: linux-2.6.18-rc6-mm1/include/linux/gfp.h
=================================--- linux-2.6.18-rc6-mm1.orig/include/linux/gfp.h 2006-09-11 16:44:16.000000000 -0500
+++ linux-2.6.18-rc6-mm1/include/linux/gfp.h 2006-09-11 16:45:01.902224197 -0500
@@ -80,8 +80,10 @@

static inline enum zone_type gfp_zone(gfp_t flags)
{
+#ifdef CONFIG_ZONE_DMA
if (flags & __GFP_DMA)
return ZONE_DMA;
+#endif
#ifdef CONFIG_ZONE_DMA32
if (flags & __GFP_DMA32)
return ZONE_DMA32;
Index: linux-2.6.18-rc6-mm1/mm/slab.c
=================================--- linux-2.6.18-rc6-mm1.orig/mm/slab.c 2006-09-11 16:44:16.000000000 -0500
+++ linux-2.6.18-rc6-mm1/mm/slab.c 2006-09-11 16:45:01.919803815 -0500
@@ -1441,13 +1443,14 @@
ARCH_KMALLOC_FLAGS|SLAB_PANIC,
NULL, NULL);
}
-
+#ifdef CONFIG_ZONE_DMA
sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
sizes->cs_size,
ARCH_KMALLOC_MINALIGN,
ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA|
SLAB_PANIC,
NULL, NULL);
+#endif
sizes++;
names++;
}
@@ -2275,8 +2278,10 @@
cachep->slab_size = slab_size;
cachep->flags = flags;
cachep->gfpflags = 0;
+#ifdef CONFIG_ZONE_DMA
if (flags & SLAB_CACHE_DMA)
cachep->gfpflags |= GFP_DMA;
+#endif
cachep->buffer_size = size;

if (flags & CFLGS_OFF_SLAB) {
Index: linux-2.6.18-rc6-mm1/include/linux/slab.h
=================================--- linux-2.6.18-rc6-mm1.orig/include/linux/slab.h 2006-09-11 16:44:16.000000000 -0500
+++ linux-2.6.18-rc6-mm1/include/linux/slab.h 2006-09-11 16:45:01.931523561 -0500
@@ -72,7 +72,11 @@
struct cache_sizes {
size_t cs_size;
kmem_cache_t *cs_cachep;
+#ifdef CONFIG_ZONE_DMA
kmem_cache_t *cs_dmacachep;
+#else
+#define cs_dmacachep cs_cachep
+#endif
};
extern struct cache_sizes malloc_sizes[];

Index: linux-2.6.18-rc6-mm1/mm/vmstat.c
=================================--- linux-2.6.18-rc6-mm1.orig/mm/vmstat.c 2006-09-11 16:44:16.000000000 -0500
+++ linux-2.6.18-rc6-mm1/mm/vmstat.c 2006-09-11 16:45:01.940313371 -0500
@@ -437,6 +437,12 @@
.show = frag_show,
};

+#ifdef CONFIG_ZONE_DMA
+#define TEXT_FOR_DMA(xx) xx "_dma",
+#else
+#define TEXT_FOR_DMA(xx)
+#endif
+
#ifdef CONFIG_ZONE_DMA32
#define TEXT_FOR_DMA32(xx) xx "_dma32",
#else
@@ -449,7 +455,7 @@
#define TEXT_FOR_HIGHMEM(xx)
#endif

-#define TEXTS_FOR_ZONES(xx) xx "_dma", TEXT_FOR_DMA32(xx) xx "_normal", \
+#define TEXTS_FOR_ZONES(xx) TEXT_FOR_DMA(xx) TEXT_FOR_DMA32(xx) xx "_normal", \
TEXT_FOR_HIGHMEM(xx)

static char *vmstat_text[] = {
Index: linux-2.6.18-rc6-mm1/include/linux/vmstat.h
=================================--- linux-2.6.18-rc6-mm1.orig/include/linux/vmstat.h 2006-09-11 16:44:16.000000000 -0500
+++ linux-2.6.18-rc6-mm1/include/linux/vmstat.h 2006-09-11 16:45:01.949103180 -0500
@@ -17,6 +17,12 @@
* generated will simply be the increment of a global address.
*/

+#ifdef CONFIG_ZONE_DMA
+#define DMA_ZONE(xx) xx##_DMA,
+#else
+#define DMA_ZONE(xx)
+#endif
+
#ifdef CONFIG_ZONE_DMA32
#define DMA32_ZONE(xx) xx##_DMA32,
#else
@@ -29,7 +35,7 @@
#define HIGHMEM_ZONE(xx)
#endif

-#define FOR_ALL_ZONES(xx) xx##_DMA, DMA32_ZONE(xx) xx##_NORMAL HIGHMEM_ZONE(xx)
+#define FOR_ALL_ZONES(xx) DMA_ZONE(xx) DMA32_ZONE(xx) xx##_NORMAL HIGHMEM_ZONE(xx)

enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
FOR_ALL_ZONES(PGALLOC),
@@ -88,7 +94,8 @@
#endif /* CONFIG_VM_EVENT_COUNTERS */

#define __count_zone_vm_events(item, zone, delta) \
- __count_vm_events(item##_DMA + zone_idx(zone), delta)
+ __count_vm_events(item##_NORMAL - ZONE_NORMAL + \
+ zone_idx(zone), delta)

/*
* Zone based page accounting with per cpu differentials.
@@ -135,14 +142,16 @@
struct zone *zones = NODE_DATA(node)->node_zones;

return
+#ifdef CONFIG_ZONE_DMA
+ zone_page_state(&zones[ZONE_DMA], item) +
+#endif
#ifdef CONFIG_ZONE_DMA32
zone_page_state(&zones[ZONE_DMA32], item) +
#endif
- zone_page_state(&zones[ZONE_NORMAL], item) +
#ifdef CONFIG_HIGHMEM
zone_page_state(&zones[ZONE_HIGHMEM], item) +
#endif
- zone_page_state(&zones[ZONE_DMA], item);
+ zone_page_state(&zones[ZONE_NORMAL], item);
}

extern void zone_statistics(struct zonelist *, struct zone *);