Great news, up until now there was no good Lua profiler.<p>You can thank GIANTS Software for this one: <a href="http://luajit.org/sponsors.html" rel="nofollow">http://luajit.org/sponsors.html</a><p><i>GIANTS Software GmbH is sponsoring the development of a low-overhead profiling functionality for LuaJIT 2.1, starting in June 2013. GIANTS Software develops a variety of simulation games for desktop, mobile and consoles. These games make extensive use of Lua for scripting and modding. Switching to LuaJIT was instrumental in reducing the CPU load and sustaining the required frame rates on all platforms.<p>Existing profilers for Lua and LuaJIT are based on Lua hooks and debug queries. The use of these generic mechanisms incurs a high overhead. Execution of a program under control of such a profiler causes substantial slow-downs. Actual use of the program (gameplay) may be impossible in some cases.<p>The goal is to design and implement a new profiling functionality that has a much lower overhead, better control of detail and high flexibility.</i>