On Thu, 9 Mar 2006, Zoltan Menyhart wrote: > In short: unless we use "srlz.d", how to make sure: > - the visibility of the "itc" instruction to generated purges is > guaranteed first > - issuing "ld" goes after ? The manual states that serialization is only necessary before a data access uses the mapping. We do not use the mapping in the function we are discussing and I would think that the rfi is certainly serialization enough. The manual also has a rather complex section on ptc purges. I think we need to refer to how our purges work under ia64. What we do in essence from the remote processor is: 1. We invalidate a pte (overwite the entry with zero) 2. We purge the caches (and then broadcast the purge?). So if the fault handlers run then they will discover that either the pte has been zapped or the cmpxchg will fail. In either case we just do nothing and redo the fault. I guess this scheme could fail if the remote processor would zap the pte and do the broadcast between the local processors cmpxchg and the itc. Thats only two bundles. Maybe we need some experts to explain the situation. Ken? David? - : 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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