Re: [PATCH 8/8] intel_idle: create a native cpuidle driver for selectintel processors

From: Len Brown
Date: Thu May 27 2010 - 23:58:02 EST



> ... What happens when an additional CPU is brought online?
> It melts? ;)

With the current driver, processors hot-added after modprobe
will use C1 only, and not use deeper C-states.

Taking online processors offline and bringing them back online
(like we do during suspend) works fine.

> > + dev->cpu = i;
> > + if (cpuidle_register_device(dev)) {
> > + pr_debug(PREFIX "cpuidle_register_device %d failed!\n", i);
> > + free_percpu(intel_idle_cpuidle_devices);
> > + return -EIO;
>
> Should this unregister all the thus-far-registered devices?

yes, that was a bug!

thanks,
Len Brown, Intel Open Source Technology Center

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