[tesla-dev] re-initialize APIC timer

[Eric Saxe]

Liu, Jiang wrote:
> The processor in offline/sparse/faulted states will run idle thread with
> interrupt enabled or disabled. 
> But you can't rely on normal idleness prediction algorithm to put
> offline cpu into deep C state because there may be only one chance to
> put cpu into any C state before it is put online again.
> So to put offlined cpu into deep C state, you need to check cpu offline
> state before adopting normal idleness prediction algorithm to choose cpu
> C state. 
>   
Depending on what the idleness predication algorithm looks at, a CPU 
just marked as offline, that has already had it's cyclics juggled away, 
no timeouts pending, etc. might look like a good candidate for deep 
sleeping anyways (at least in terms of what is scheduled in the future).

-Eric