lkml.org 
[lkml]   [2014]   [Jan]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v9 3/5] qrwlock, x86 - Treat all data type not bigger than long as atomic in x86
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


\
 
 \ /
  Last update: 2014-01-21 17:21    [W:0.157 / U:1.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site