RE: Synchronizing Bit operations V2

[Christoph Lameter]

On Fri, 31 Mar 2006, Chen, Kenneth W wrote:

> > I think we could say that lock semantics are different from barriers. They 
> > are more like acquire and release on IA64. The problem with smb_mb_*** is 
> > that the coder *explicitly* requested a barrier operation and we do not 
> > give it to him.
> 
> I was browsing sparc64 code and it defines:
> 
> include/asm-sparc64/bitops.h:
> #define smp_mb__after_clear_bit()      membar_storeload_storestore()
> 
> With my very naïve knowledge of sparc64, it doesn't look like a full barrier.
> Maybe sparc64 is broken too ...

Dave, how does sparc64 handle this situation?