Messages in this thread | | | Date | Tue, 21 Jan 2014 10:36:48 -0500 | From | Waiman Long <> | Subject | Re: [PATCH v9 3/5] qrwlock, x86 - Treat all data type not bigger than long as atomic in x86 |
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On 01/20/2014 10:03 AM, Peter Zijlstra wrote: > On Tue, Jan 14, 2014 at 11:44:05PM -0500, Waiman Long wrote: >> The generic __native_word() macro defined in include/linux/compiler.h >> only allows "int" and "long" data types to be treated as native and >> atomic. The x86 architecture, however, allow the use of char and short >> data types as atomic as well. >> >> This patch extends the data type allowed in the __native_word() macro to >> allow the use of char and short. >> >> Signed-off-by: Waiman Long<Waiman.Long@hp.com> >> --- >> arch/x86/include/asm/barrier.h | 8 ++++++++ >> 1 files changed, 8 insertions(+), 0 deletions(-) >> >> diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h >> index 04a4890..4d3e30a 100644 >> --- a/arch/x86/include/asm/barrier.h >> +++ b/arch/x86/include/asm/barrier.h >> @@ -24,6 +24,14 @@ >> #define wmb() asm volatile("sfence" ::: "memory") >> #endif >> >> +/* >> + * All data types<= long are atomic in x86 >> + */ >> +#ifdef __native_word >> +#undef __native_word >> +#endif >> +#define __native_word(t) (sizeof(t)<= sizeof(long)) > Yeah, not going to happen.
Does explicit list of acceptable sizes work for you?
#define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int ) || sizeof(t) == sizeof(long))
-Longman
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