luanti/doc/developing/misc.md

Miscellaneous

Profiling Minetest on Linux

We will be using a tool called "perf", which you can get by installing perf or linux-perf or linux-tools-common.

For best results build Minetest and Irrlicht with debug symbols (-DCMAKE_BUILD_TYPE=RelWithDebInfo or -DCMAKE_BUILD_TYPE=Debug).

Run the client (or server) like this and do whatever you wanted to test:

perf record -z --call-graph dwarf -- ./bin/minetest

This will leave a file called "perf.data".

You can open this file with perf built-in tools but much more interesting is the visualization using a GUI tool: Hotspot. It will give you flamegraphs, per-thread, per-function views and much more.