update readme

README.md

@@ -43,6 +43,11 @@ Screen recording of AFL running on Rust code.
 
 ## Hints
 
+Before starting to fuzz you should reconfigure your system for optimal
+performance and better crash detection. This can be done with `cargo-afl afl system-config`
+but this requires root so it is run with sudo, hence you might need to enter
+your password.
+
 By default, the AFL++ [CMPLOG](https://github.com/AFLplusplus/AFLplusplus/blob/stable/instrumentation/README.cmplog.md)
 feature is activated, which helps to achieve good code coverage.
 However, it is not beneficial to activate CMPLOG on more than two instances.