[avr-gcc-list] when is it safe to use -mtiny-stack

[sjuid-avr]

I have an ATmega3290P app that I am trying to optimize for size.
I find that using the -mtiny-stack option gives me the last bit of size 
reduction I need to make it fit. 
However, from the one line description of this option I've found, it doesn't 
seem right that this option could be used blindly
So, while I'm happy about the code size, I have a sneaky feeling I might have 
runtime problems.

Are there any caveats to the use of this option?
How would one know if it is safe to use for a given code base?

thx.