Re: [patch 2/3] intel_idle: disable auto_demotion for hotplugged CPUs

[Len Brown <lenb@kernel.org>]

Andrew,
Per reasoning from Thomas below, please drop this one.

thanks,
-Len

On 01/17/2012 05:56 AM, Thomas Renninger wrote:

> On Wednesday, January 11, 2012 12:48:20 AM akpm@linux-foundation.org wrote:
>> From: Shaohua Li <shaohua.li@intel.com>
>> Subject: intel_idle: disable auto_demotion for hotplugged CPUs
> 
> This one should not be necessary anymore with my intel_idle
> patch series I have to rebase and resend (will do that after lunch).
> 
> It provides a per cpu intel_idle init function which is called
> from processor.ko in physical cpu hotplug case.
> 
> From what I can see this patch does not change anything/much, because:
>   - CPUs onlined at bootup are initialized correctly already
>   - Soft offlining/onlining shouldn't matter in auto_demotion_disable
>     case as it's a HW MSR write and the CPU should still be in the
>     same state after off- and onlined again.
>   - Physically hotplugged/added CPUs are not registered with cpuidle
>     at all (this is what my patch series fixes), because intel_idle
>     does not offer any per cpu init() entry function.
>     With this patch they might be set into auto_demotion_disable now,
>     but no idle driver gets active for them.
> 
> I'll pick up patch 1/3 and 3/3, base my patches on top and resend
> everything, that should be easiest for everybody?
> 
>    Thomas
>