[PATCH] optional ZONE_DMA: optional ZONE_DMA in the VM
Make ZONE_DMA optional in core code.
- ifdef all code for ZONE_DMA and related definitions 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.
[akpm@osdl.org: cleanup]
[jdike@addtoit.com: build fix]
[apw@shadowen.org: Simplify calculation of the number of bits we need for ZONES_SHIFT]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/Kconfig b/mm/Kconfig
index 50f7cfc..79360cf 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -161,3 +161,9 @@
default 64BIT
help
This option allows memory and IO resources to be 64 bit.
+
+config ZONE_DMA_FLAG
+ int
+ default "0" if !ZONE_DMA
+ default "1"
+
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6cff138..d461b23 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -73,7 +73,9 @@
* 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
@@ -85,7 +87,9 @@
EXPORT_SYMBOL(totalram_pages);
static char * const zone_names[MAX_NR_ZONES] = {
+#ifdef CONFIG_ZONE_DMA
"DMA",
+#endif
#ifdef CONFIG_ZONE_DMA32
"DMA32",
#endif
diff --git a/mm/slab.c b/mm/slab.c
index caa8f87..348396d 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -793,8 +793,10 @@
* has cs_{dma,}cachep==NULL. Thus no special case
* for large kmalloc calls required.
*/
+#ifdef CONFIG_ZONE_DMA
if (unlikely(gfpflags & GFP_DMA))
return csizep->cs_dmacachep;
+#endif
return csizep->cs_cachep;
}
@@ -1493,13 +1495,15 @@
ARCH_KMALLOC_FLAGS|SLAB_PANIC,
NULL, NULL);
}
-
- sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
+#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++;
}
@@ -2321,7 +2325,7 @@
cachep->slab_size = slab_size;
cachep->flags = flags;
cachep->gfpflags = 0;
- if (flags & SLAB_CACHE_DMA)
+ if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
cachep->gfpflags |= GFP_DMA;
cachep->buffer_size = size;
cachep->reciprocal_buffer_size = reciprocal_value(size);
@@ -2643,10 +2647,12 @@
static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
{
- if (flags & GFP_DMA)
- BUG_ON(!(cachep->gfpflags & GFP_DMA));
- else
- BUG_ON(cachep->gfpflags & GFP_DMA);
+ if (CONFIG_ZONE_DMA_FLAG) {
+ if (flags & GFP_DMA)
+ BUG_ON(!(cachep->gfpflags & GFP_DMA));
+ else
+ BUG_ON(cachep->gfpflags & GFP_DMA);
+ }
}
static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 5ffa8c2..6c488d6 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -408,6 +408,12 @@
.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
@@ -420,7 +426,7 @@
#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 const char * const vmstat_text[] = {