Un-suspending the scheduler is slow?

alainm3 wrote on Tuesday, August 11, 2009:

Hi Richard,

in FreeRTOS manual it says: “but resuming (or ‘un-suspending’) the scheduler has the potential of being a potentialy lengthy operation…”

Could you elaborate on this, please? Am I right in assuming that it can be lengthy in case of a task-switch? Would it not be a time that had to be lost anyway?


davedoors wrote on Tuesday, August 11, 2009:

Tick interrupts that occur while the scheduler is suspended are held pending and instead processed when the scheduler is un suspended. I think this is what it is referring to. It should not really be a long operation unless the scheduler has been suspended for a long time and there are a lot of pending ticks to process, but that would be bad practice anyway. The scheduler should only be suspended for very short periods.