Christoph Lameter wrote on Thursday, March 30, 2006 7:02 PM > We are talking about IA64 and IA64 only generates an single instruction > with either release or acquire semantics for the case in which either > smb_mb__before/after_clear_bit does nothing. > > Neither acquire nor release is a memory barrier on IA64. The use of smp_mb__before_clear_bit(); clear_bit( ... ); is: all memory operations before this call will be visible before the clear_bit(). To me, that's release semantics. On ia64, we map the following: #define Smp_mb__before_clear_bit do { } while (0) #define clear_bit clear_bit_mode(..., RELEASE) Which looked perfect fine to me. I don't understand why you say it does not provide memory ordering. - Ken - : 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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