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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-01-12 17:57:35 -0800 |
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committer | H. Peter Anvin <hpa@zytor.com> | 2010-01-13 22:38:51 -0800 |
commit | 5d0b7235d83eefdafda300656e97d368afcafc9a (patch) | |
tree | 4d6d7036b4f89780dcce1b39ce17cc47038b2a6c /arch/x86/Kconfig.cpu | |
parent | 3bef444797f7624f8fbd27f4e0334ce96a108725 (diff) | |
download | linux-5d0b7235d83eefdafda300656e97d368afcafc9a.tar.bz2 |
x86: clean up rwsem type system
The fast version of the rwsems (the code that uses xadd) has
traditionally only worked on x86-32, and as a result it mixes different
kinds of types wildly - they just all happen to be 32-bit. We have
"long", we have "__s32", and we have "int".
To make it work on x86-64, the types suddenly matter a lot more. It can
be either a 32-bit or 64-bit signed type, and both work (with the caveat
that a 32-bit counter will only have 15 bits of effective write
counters, so it's limited to 32767 users). But whatever type you
choose, it needs to be used consistently.
This makes a new 'rwsem_counter_t', that is a 32-bit signed type. For a
64-bit type, you'd need to also update the BIAS values.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <alpine.LFD.2.00.1001121755220.17145@localhost.localdomain>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/Kconfig.cpu')
0 files changed, 0 insertions, 0 deletions