richard_damon wrote on Thursday, January 19, 2012:
What do you need a high tick rate for? High Data rates do NOT need high tick rates. You should only need a high tick rate if you have activities that happen at a high rate BASED STRICTLY ON A TIMER, and not a “data ready” interrupt from a device, or if you need to precisely control timeouts.
You say that your high priority task is “polling”, if you are truly doing that, that is killing your system. One of the biggest purposes of a RTOS is to remove polling, and converting activities to interrupt based and run on demand.
If your polling is at a 1KHz rate you are sending out messages to a bunch of devices and waiting for replies, (and all the I/o is being interrupt driven), and that is saturating your processor, then you need more processor or a more efficient I/O system.
ALL devices should be running interrupt based, with the interrupt handling a minimal data gathering step and passing that on to a task to process. Then you will probably find that you can use a 10ms or maybe even a 100ms tick rate (those are about right for the timeouts needed by those protocols.