RTOS: windows ce: can I perform all my calculations in kernel mode for a PID control loop?

In Windows CE, 开发者_StackOverflow社区can I do all my calucation for a PID(Proportional-Integral-Derivative) control loop in "kernel mode" and avoid using "user mode"? I will transfering data over TCP=IP to another machine for the end result to keep the system in "kernel mode". My understanding is that switching from "kernel mode" to "user mode" and vice versa costs time..ie 40us round trip.

I think you can do that, you should call SetKMode function to put your thread out or in of kernel mode. More details in these two blog posts from CE team: What is Kernel Mode? and Inside Windows CE API Calls.