> This could be achieved if s390 (or if we had a generic one, this is
> another story...) had a for_each_cpu type iterator, which would also
> cover aforementioned mask &= cpu_online_map issue, but as an aside, it is
> harder to track down lockups from things like IPIs to invalid cpus than a busy loop
> waiting for num_cpus.
I'm not sure I understand what you mean here. In any case, at least
on S/390, doing a SIGP to an invalid CPU will simply get you an
'not operational' indication (condition code 3), so in fact the
only problem *is* the busy loop on num_cpus ...
Bye,
Ulrich
-- Dr. Ulrich Weigand weigand@informatik.uni-erlangen.de - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/