Re: [PATCH 3/7] idle, thermal, acpi: Remove home grown idle implementations

Arjan van de Ven
2013-11-20T17:23:57Z

On 11/20/2013 9:23 AM, Thomas Gleixner wrote:
> On Wed, 20 Nov 2013, Arjan van de Ven wrote:
>
>> On 11/20/2013 8:04 AM, Peter Zijlstra wrote:
>>> This does not fully preseve existing behaviour in that the generic
>>> idle cycle function calls into the normal cpuidle governed idle
>>> routines and should thus respect things like QoS parameters and the
>>> like.
>>
>>
>> NAK on the powerclamp side.
>>
>> powerclamp MUST NOT do that....
>> it is needed to go to the deepest state no matter what
>> (this is for when your system is overheating. there is not a lot of choice
>> here... alternative is an emergency reset that the hardware does for safety)
>
> So that whole machinery falls apart when the thing which is running on
> that hot core is a while(1) loop with a higher or equal FIFO priority
> than this thread. Even if you'd run at prio 99, then there is no
> guarantee that the cpu hog does not run with prio 99 as well and due
> to FIFO and being on the CPU it's not going to let you on.

the idea was to at least give people who know what they're doing a chance to run