Permit overriding maximum stack size

[Alan-Jowett]

Permit overriding maximum stack size at compile time.

Resolves: #65

Signed-off-by: Alan Jowett alan.jowett@microsoft.com

[coveralls]

Coverage remained the same at 95.541% when pulling ebd802c on Alan-Jowett:issue65 into 6492b7a on iovisor:master.

[jpsamaroo]

I think you meant this resolves #65, which it doesn't seem to, since you keep the default stack size at 128. Maybe bump it to 512 here as well?

[Alan-Jowett]

The intent is to leave the default at 128 (not sure why that value was picked, but don't want to break anyone's code that depends on it).

By wrapping this in a #if !defined(STACK_SIZE) I can override it at compile time.

[rlane]

Could you move the #define to ubpf.h, and add a "UBPF_" prefix to it? That way the config option is better documented.

[Alan-Jowett]

Great idea, moved both limits to ubpf.h and added a note that they are defaults values.