* [PATCH] zone gfp_flags generate from ZONE_ constants
@ 2006-01-17 15:52 Andy Whitcroft
2006-01-17 21:22 ` Andrew Morton
0 siblings, 1 reply; 2+ messages in thread
From: Andy Whitcroft @ 2006-01-17 15:52 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-mm, linux-kernel
zone gfp_flags generate from ZONE_ constants
Change the allocation of the __GFP_zone style zone modifiers so that
they are generated from the values of the ZONE_zone definitions.
Note that when no zone modifiers are specified select the default
zone, typically ZONE_NORMAL.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
---
gfp.h | 22 ++++++++++++++++------
mmzone.h | 2 ++
2 files changed, 18 insertions(+), 6 deletions(-)
diff -upN reference/include/linux/gfp.h current/include/linux/gfp.h
--- reference/include/linux/gfp.h
+++ current/include/linux/gfp.h
@@ -11,15 +11,25 @@ struct vm_area_struct;
/*
* GFP bitmasks..
*/
-/* 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)
+
+/*
+ * Generate the zone modifier bit. Zone ZONE_DEFAULT doesn't require a bit
+ * as the absence of all zone modifiers implies this zone. Renormalise the
+ * zone number such that ZONE_DEFAULT is at the bottom and discard it.
+ * These must fit within the bitmask GFP_ZONEMASK defined in linux/mmzone.h.
+ */
+#define __ZONE_BIT(x) (((x) ^ ZONE_DEFAULT) - 1)
+#define ZONE_MODIFIER(x) ((__force gfp_t)(((x) == ZONE_DEFAULT)? (0) : \
+ 1UL << __ZONE_BIT(x)))
+
+#define __GFP_DMA ZONE_MODIFIER(ZONE_DMA)
+#define __GFP_HIGHMEM ZONE_MODIFIER(ZONE_HIGHMEM)
#ifdef CONFIG_DMA_IS_DMA32
-#define __GFP_DMA32 ((__force gfp_t)0x01) /* ZONE_DMA is ZONE_DMA32 */
+#define __GFP_DMA32 ZONE_MODIFIER(ZONE_DMA) /* ZONE_DMA is ZONE_DMA32 */
#elif BITS_PER_LONG < 64
-#define __GFP_DMA32 ((__force gfp_t)0x00) /* ZONE_NORMAL is ZONE_DMA32 */
+#define __GFP_DMA32 ZONE_MODIFIER(ZONE_NORMAL) /* ZONE_NORMAL is ZONE_DMA32 */
#else
-#define __GFP_DMA32 ((__force gfp_t)0x04) /* Has own ZONE_DMA32 */
+#define __GFP_DMA32 ZONE_MODIFIER(ZONE_DMA32) /* Has own ZONE_DMA32 */
#endif
/*
diff -upN reference/include/linux/mmzone.h current/include/linux/mmzone.h
--- reference/include/linux/mmzone.h
+++ current/include/linux/mmzone.h
@@ -77,6 +77,8 @@ struct per_cpu_pageset {
#define MAX_NR_ZONES 4 /* Sync this with ZONES_SHIFT */
#define ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */
+/* Select the zone to use when no __GFP flags are selected. */
+#define ZONE_DEFAULT ZONE_NORMAL
/*
* When a memory allocation must conform to specific limitations (such
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] zone gfp_flags generate from ZONE_ constants
2006-01-17 15:52 [PATCH] zone gfp_flags generate from ZONE_ constants Andy Whitcroft
@ 2006-01-17 21:22 ` Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2006-01-17 21:22 UTC (permalink / raw)
To: Andy Whitcroft; +Cc: linux-mm, linux-kernel
Andy Whitcroft <apw@shadowen.org> wrote:
>
> +/*
> + * Generate the zone modifier bit. Zone ZONE_DEFAULT doesn't require a bit
> + * as the absence of all zone modifiers implies this zone. Renormalise the
> + * zone number such that ZONE_DEFAULT is at the bottom and discard it.
> + * These must fit within the bitmask GFP_ZONEMASK defined in linux/mmzone.h.
> + */
> +#define __ZONE_BIT(x) (((x) ^ ZONE_DEFAULT) - 1)
> +#define ZONE_MODIFIER(x) ((__force gfp_t)(((x) == ZONE_DEFAULT)? (0) : \
> + 1UL << __ZONE_BIT(x)))
> +
> +#define __GFP_DMA ZONE_MODIFIER(ZONE_DMA)
> +#define __GFP_HIGHMEM ZONE_MODIFIER(ZONE_HIGHMEM)
> #ifdef CONFIG_DMA_IS_DMA32
> -#define __GFP_DMA32 ((__force gfp_t)0x01) /* ZONE_DMA is ZONE_DMA32 */
> +#define __GFP_DMA32 ZONE_MODIFIER(ZONE_DMA) /* ZONE_DMA is ZONE_DMA32 */
> #elif BITS_PER_LONG < 64
> -#define __GFP_DMA32 ((__force gfp_t)0x00) /* ZONE_NORMAL is ZONE_DMA32 */
> +#define __GFP_DMA32 ZONE_MODIFIER(ZONE_NORMAL) /* ZONE_NORMAL is ZONE_DMA32 */
> #else
> -#define __GFP_DMA32 ((__force gfp_t)0x04) /* Has own ZONE_DMA32 */
> +#define __GFP_DMA32 ZONE_MODIFIER(ZONE_DMA32) /* Has own ZONE_DMA32 */
> #endif
eek. We often look at the hex value of gfp flags in debug output to work
out what sort of allocation is being attempted.
I guess we could print out the values of these things at boot time..
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2006-01-17 21:22 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2006-01-17 15:52 [PATCH] zone gfp_flags generate from ZONE_ constants Andy Whitcroft
2006-01-17 21:22 ` Andrew Morton
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).