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Date: Sat, 23 Aug 2008 11:58:07 +0200
From: Philippe Gerum <rpm@xenomai.org>
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Subject: Re: [Xenomai-core] [PATCH] Remove redundant LOCK prefix
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To: Jan Kiszka <jan.kiszka@domain.hid>
Cc: Xenomai-core@domain.hid

Jan Kiszka wrote:
> According to Linux and the Intel spec, this prefix is not needed.
>

Obviously, it's not, since the whole purpose of xchg() is to guarantee bus
locking for memory operands anyway. Please merge.

> ---
>  include/asm-x86/atomic_32.h |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: b/include/asm-x86/atomic_32.h
> ===================================================================
> --- a/include/asm-x86/atomic_32.h
> +++ b/include/asm-x86/atomic_32.h
> @@ -64,7 +64,7 @@ struct __xeno_xchg_dummy { unsigned long
>  static inline unsigned long xnarch_atomic_xchg (volatile void *ptr,
>  						unsigned long x)
>  {
> -	__asm__ __volatile__(LOCK_PREFIX "xchgl %0,%1"
> +	__asm__ __volatile__("xchgl %0,%1"
>  			     :"=r" (x)
>  			     :"m" (*__xeno_xg(ptr)), "0" (x)
>  			     :"memory");
> 
> 
> 
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-- 
Philippe.