Thank you for your answer, but I want to know how auto tune judge whether a config is fit your device well. Because I also encountered a error code 6 with compilation timeout, but if I skip the tune process and take the error config as input to build(with autotvm.apply_history_best(‘error config’), it’s also have a good performance result. (I also tried to increase the value of timeout, but it‘s seem not work). So do you know why? Thanks