It has been three years when that same question was made:
At that time Richard said that there wasn’t so many people interested in the topic. Three years later, power-savings is a big concern for a lot of engineers.
Changing the clock frequency as the system is running makes a lot of sense, and virtually all microcontrollers are able to run from different clock sources:
1.- From very innacurate low frequency internal clock (the one used for the watchdog, for example)
2.- From an accurate RC internal clock
3.- From an accurate external 32KHz (RTC)
4.- And the king of all, external high frequency and very accurate crystal based oscillator.
(5.- And all of them
So it would be nice to move from one source to another as the power requirements dictates. The (any) RTOS should adapt to the application, and not in the opposite direction.
As far as I know the newest FreeRTOS feature towards power-saving is the tickless one, that in its own is a big step.
So the question is: FreeRTOS has a mechanism that follows any dynamic clock frequency change?