Hello! On Fri, Sep 19, 2014 at 7:25 PM, joe wrote: > However when JIT compilation > is enabled, we actually experience a significant performance decrease > compared to when it is disabled, roughly 15-20%. Will you try the on-CPU flame graph tools to generate a graph for your loaded game hot on CPU? See https://github.com/openresty/nginx-systemtap-toolkit#sample-bt Perferrably, you can generate another graph for the same game with JIT disabled so that we can compare. By looking at the flame graphs, we can immediately know if it is LuaJIT VM entry/exit being hot, or anything else. Regards, -agentzh