New users that are not from Linux-based embedded backgrounds often have an expectation of real-time performance. Linux is not a real-time operating system (RTOS). It is beyond the scope of this book to fully address this point but some clarification of potential confusion is needed.
Real-time performance means repeatable and predictable timing behavior. It does not mean higher performance as the name would suggest. Real-time performance is often needed in embedded devices so they can respond to external events in a timely manner. For example, maintaining a consistent motor speed from a BeagleBone requires the BeagleBone to respond to the motor speed measurements in a consistent manner.
On the BeagleBone systems running Linux, real-time behavior can be addressed in the following ways for noncritical systems:
Compared to many smaller embedded systems, the BeagleBone is considerably faster. This may be enough to approximate the real time for most of the...