* Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > > i might be missing something fundamental here, but why not just > > have per CPU helper threads, all on the same waitqueue, and wake > > them up via a single wake_up() call? That would remove the SMP > > cross call (wakeups do immediate cross-calls already). > > My concern with this is that the cache misses accessing all the > processes on this single waitqueue would be serialized, slowing > things down. In contrast, the bitmask that smp_call_function() > traverses delivers on the order of a thousand CPUs' worth of bits > per cache miss. I will give it a try, though. At least if you go via the migration threads, you can queue up requests to them locally. But there's going to be cachemisses _anyway_, since you have to access them all from a single CPU, and then they have to fetch details about what to do, and then have to notify the originator about completion. Ingo -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
