Messages in this thread Patch in this message | | | From | Paul Jackson <> | Date | Wed, 14 May 2008 08:15:23 -0700 | Subject | [PATCH 4/10] x86 boot: simplify pageblock_bits enum declaration |
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From: Paul Jackson <pj@sgi.com>
The use of #defines with '##' pre-processor concatenation is a useful way to form several symbol names with a common pattern. But when there is just a single name obtained from that #define, it's just obfuscation. Better to just write the plain symbol name, as is.
The following patch is a result of my wasting ten minutes looking through the kernel to figure out what 'PB_migrate_end' meant, and forgetting what I came to do, by the time I figured out that the #define PB_range macro defined it.
Signed-off-by: Paul Jackson <pj@sgi.com>
--- include/linux/pageblock-flags.h | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
--- linux.orig/include/linux/pageblock-flags.h 2008-05-13 05:42:39.869811856 -0700 +++ linux/include/linux/pageblock-flags.h 2008-05-13 05:51:47.994829315 -0700 @@ -25,13 +25,11 @@ #include <linux/types.h> -/* Macro to aid the definition of ranges of bits */ -#define PB_range(name, required_bits) \ - name, name ## _end = (name + required_bits) - 1 - /* Bit indices that affect a whole block of pages */ enum pageblock_bits { - PB_range(PB_migrate, 3), /* 3 bits required for migrate types */ + PB_migrate, + PB_migrate_end = PB_migrate + 3 - 1, + /* 3 bits required for migrate types */ NR_PAGEBLOCK_BITS }; -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson <pj@sgi.com> 1.650.933.1373
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