Re: [RFC PATCH 3/3] sched: introduce synchronized idle injection

Arjan van de Ven
2015-11-05T14:23:00Z

On 11/5/2015 2:09 AM, Peter Zijlstra wrote:

> I can see such a scheme having a fairly big impact on latency, esp. with
> forced idleness such as this. That's not going to be popular for many
> workloads.

idle injection is a last ditch effort in thermal management, before
this gets used the hardware already has clamped you to a low frequency,
reduced memory speeds, probably dimmed your screen etc etc.

at this point there are 3 choices
1) Shut off the device
2) do uncoordinated idle injection for 40% of the time
3) do coordinated idle injection for 5% of the time

as much as force injecting idle in a synchronized way sucks, the alternatives are worse.

>