[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.
[[email protected]: cleanup]
[[email protected]: build fix]
[[email protected]: Simplify calculation of the number of bits we need for ZONES_SHIFT]
Signed-off-by: Christoph Lameter <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Kyle McMartin <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Paul Mundt <[email protected]>
Signed-off-by: Andy Whitcroft <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 063799e..2a7d15b 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -85,8 +85,10 @@
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;
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 398f2ec..ee9e314 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -96,6 +96,7 @@
#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
@@ -116,6 +117,7 @@
* <16M.
*/
ZONE_DMA,
+#endif
#ifdef CONFIG_ZONE_DMA32
/*
* x86_64 needs two ZONE_DMAs because it supports devices that are
@@ -152,11 +154,27 @@
* match the requested limits. See gfp_zone() in include/linux/gfp.h
*/
-#if !defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_HIGHMEM)
+/*
+ * Count the active zones. Note that the use of defined(X) outside
+ * #if and family is not necessarily defined so ensure we cannot use
+ * it later. Use __ZONE_COUNT to work out how many shift bits we need.
+ */
+#define __ZONE_COUNT ( \
+ defined(CONFIG_ZONE_DMA) \
+ + defined(CONFIG_ZONE_DMA32) \
+ + 1 \
+ + defined(CONFIG_HIGHMEM) \
+)
+#if __ZONE_COUNT < 2
+#define ZONES_SHIFT 0
+#elif __ZONE_COUNT <= 2
#define ZONES_SHIFT 1
-#else
+#elif __ZONE_COUNT <= 4
#define ZONES_SHIFT 2
+#else
+#error ZONES_SHIFT -- too many zones configured adjust calculation
#endif
+#undef __ZONE_COUNT
struct zone {
/* Fields commonly accessed by the page allocator */
@@ -523,7 +541,11 @@
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 */
diff --git a/include/linux/slab_def.h b/include/linux/slab_def.h
index 4b463e6..5e43646 100644
--- a/include/linux/slab_def.h
+++ b/include/linux/slab_def.h
@@ -19,7 +19,9 @@
struct cache_sizes {
size_t cs_size;
struct kmem_cache *cs_cachep;
+#ifdef CONFIG_ZONE_DMA
struct kmem_cache *cs_dmacachep;
+#endif
};
extern struct cache_sizes malloc_sizes[];
@@ -39,9 +41,12 @@
__you_cannot_kmalloc_that_much();
}
found:
- return kmem_cache_alloc((flags & GFP_DMA) ?
- malloc_sizes[i].cs_dmacachep :
- malloc_sizes[i].cs_cachep, flags);
+#ifdef CONFIG_ZONE_DMA
+ if (flags & GFP_DMA)
+ return kmem_cache_alloc(malloc_sizes[i].cs_dmacachep,
+ flags);
+#endif
+ return kmem_cache_alloc(malloc_sizes[i].cs_cachep, flags);
}
return __kmalloc(size, flags);
}
@@ -62,9 +67,12 @@
__you_cannot_kzalloc_that_much();
}
found:
- return kmem_cache_zalloc((flags & GFP_DMA) ?
- malloc_sizes[i].cs_dmacachep :
- malloc_sizes[i].cs_cachep, flags);
+#ifdef CONFIG_ZONE_DMA
+ if (flags & GFP_DMA)
+ return kmem_cache_zalloc(malloc_sizes[i].cs_dmacachep,
+ flags);
+#endif
+ return kmem_cache_zalloc(malloc_sizes[i].cs_cachep, flags);
}
return __kzalloc(size, flags);
}
@@ -88,9 +96,13 @@
__you_cannot_kmalloc_that_much();
}
found:
- return kmem_cache_alloc_node((flags & GFP_DMA) ?
- malloc_sizes[i].cs_dmacachep :
- malloc_sizes[i].cs_cachep, flags, node);
+#ifdef CONFIG_ZONE_DMA
+ if (flags & GFP_DMA)
+ return kmem_cache_alloc_node(malloc_sizes[i].cs_dmacachep,
+ flags, node);
+#endif
+ return kmem_cache_alloc_node(malloc_sizes[i].cs_cachep,
+ flags, node);
}
return __kmalloc_node(size, flags, node);
}
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 77caf91..7ba91f2 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -19,6 +19,12 @@
* 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
@@ -31,7 +37,7 @@
#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),
@@ -96,7 +102,8 @@
#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.
@@ -143,14 +150,16 @@
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 *);
