Re: [PATCH] intel_rapl: Correct hotplug correction

[Borislav Petkov]

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 majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/