RE: Synchronizing Bit operations V2

From: Christoph Lameter <clameter_at_sgi.com>
Date: 2006-03-31 13:55:47
On Thu, 30 Mar 2006, Chen, Kenneth W wrote:

> By the way, this is the same thing on x86: look at include/asm-i386/bitops.h:
> 
> #define smp_mb__before_clear_bit()      barrier()
> #define smp_mb__after_clear_bit()       barrier()
> 
> A simple compiler barrier, nothing but
> #define barrier() __asm__ __volatile__("": : :"memory")
> 
> See, no memory ordering there, because clear_bit already has a LOCK prefix.

And that implies barrier behavior right?

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Received on Fri Mar 31 13:56:34 2006

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