Freeze due to performance_cx_lowest=LOW

[Nate Lawson]

Andriy Gapon wrote:
> on 29/05/2006 23:10 Nate Lawson said the following:
>> disable apic (hint.apic.0.disabled="1").  I isolated this a little while 
>> ago to the change to enable LAPIC timer.  However, there is currently no 
>> easy way to disable the LAPIC timer with APIC enabled so you have to 
>> disable APIC.  jhb@ and I have been discussing how to do this better but 
>> no easy answers apparently.
> 
> I am not sure what I am talking about, but is it potentially possible to
> drive timer system by more than one clock, actively using the most
> precise of them at any particular moment ? So that if LAPIC timer stops
> i8254 can be used instead.

That requires mixed mode delivery -- i8254 on legacy PIC irq and APIC 
mode for other interrupts.  jhb@ just killed this and isn't eager to add 
it back.  I'll let him explain if he has more to add.

-- 
Nate