Re: cyclictest better values with system load than without (OMAP3530 target)

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On 11/29/2013 04:10 PM, Carsten Emde wrote:
> BTW: Power saving and real-time do not necessarily exclude each other.
> If a - still deterministic - but a little longer latency is acceptable,
> some light sleep states and a somewhat lower clock frequency may be
> allowed which still may result in considerable energy saving. If,
> however, the fastest possible real-time response is required, C states
> and P states must be disabled (or set to polling and maximum speed,
> repsectively) and the power bill must be payed.

Well, I do not fully agree. To be sure that you can clock down the 
processor for executing a task which has sufficient time to meet its 
deadline, your system must be "time triggered", all the timer events 
must be known in advance. Because on a fully dynamic system, you may 
make that decision, but a new timer may be scheduled which causes the 
system to miss its deadline whereas it would not have missed it if it 
had run at full speed.

-- 
					    Gilles.