Performance manul vs afl++

[mxmssh]

Manul in forkmode can reach ~450-500 exec/sec on Ubuntu 16.04
AFL++ in forkmode can reach ~2500 exec/sec on the same machine.

We need to understand why it is happening. Is it a general python issue or some inefficiency in Manul code?

[mxmssh]

It looks like the main problem is that Python pipes work slower than C implementation. The following function is the main source of performance problems:

manul/manul.py

Line 92 in f7aef52

def run_via_forkserver(self):