diff options
| author | Christoph Lameter <clameter@sgi.com> | 2007-02-10 01:43:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-11 10:51:18 -0800 |
| commit | 4b51d66989218aad731a721b5b28c79bf5388c09 (patch) | |
| tree | 8ff7acbd219f699c20c2f1fd201ffb3db5a64062 /include/linux/mmzone.h | |
| parent | 66701b1499a3ff11882c8c4aef36e8eac86e17b1 (diff) | |
[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>
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 398f2ec55f54..ee9e3143df4f 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -96,6 +96,7 @@ struct per_cpu_pageset { #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 @@ enum zone_type { * <16M. */ ZONE_DMA, +#endif #ifdef CONFIG_ZONE_DMA32 /* * x86_64 needs two ZONE_DMAs because it supports devices that are @@ -152,11 +154,27 @@ enum zone_type { * 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_dma32(struct zone *zone) 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 */ |