memory - How to determine maximum stack usage?

Question

What methods are available for determining the optimum stack size for embedded/memory constrained system? If it's too big then memory is wasted that could be used elsewhere. However, if it is too small then we get this website's namesake...

To try to jump start things: Jack Ganssle states in The Art of Designing Embedded Systems that, "With experience, one learns the standard, scientific way to compute the proper size for a stack: Pick a size at random and hope." Can anyone do better than that?

A more specific example was requested. So, how about a C program targeting an MSP430 MCU with 2 kB of RAM using the IAR Embedded Workbench toolchain without an operating system? This IDE can display the stack contents and usage while using a JTAG debugger.

Answer 1

The most common way to determine the deepest stack usage is to initialize the stack memory with some known but unusual value, then periodically (or at the end of a big test run) see where that pattern stops.

This is exactly how the IAR IDE determines the amount of stack used.