On Fri, 31 Mar 2006, Andi Kleen wrote: > On Friday 31 March 2006 18:22, Hans Boehm wrote: > > > My impression is that approach (1) tends not to stick, since it involves > > a substantial performance hit on architectures on which the fence is > > not implicitly included in atomic operations. Those include Itanium and > > PowerPC. > > At least the PPC people are eating the overhead because back when they > didn't they had a long string of subtle powerpc only bugs caused by that PPC has barriers for both smb_mb_before/after cases. IMHO we should do the same for ia64 and not fuzz around. > It's a stability/maintainability vs performance issue. I doubt the > performance advantage would be worth the additional work. I guess > with the engineering time you would need to spend getting all this right > you could do much more fruitful optimizations. Agreed. - : send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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