On Thu, May 22, 2014 at 05:24:33PM +0530, Srivatsa S. Bhat wrote: > That was just me trying to explain the current mess, not justifying > it! :-/
Yes, it is a mess - thanks for explaining it. > I think Oleg had a proposed patch to use per-cpu rwsem in CPU hotplug to > drastically simplify this whole locking scheme. I think we could look at > that again. And that is my question: why can't all be made to use a single dumb lock allowing only one task and lock everything hotplug with it? Maybe it is an oversimplification but why do I care about hotplug operations scaling - they're not on the fastpath anyway. And yes, we're trying to remove CPU_POST_DEAD - I have one user in MCE which I'm testing a removal patch for - and then we can all use get_/put_online_cpus() like we used to do and be happy. Having 2 + 1 aliased hotplug sync APIs is beyond insane and is simply not needed IMHO. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/