Snabb processes analysis

Latency

Latency histogram data records the duration of each breath that the engine takes. Every breath is counted into one of ~500 bins corresponding to durations from one microsecond up to one second.

VMProfile

VMProfile data records code profiler samples. One sample is taken each microsecond and each sample is counted in a bin keyed by both the class of the app that is currently running and the virtual machine state. The apps are presented here separately.

States:

• asm when the JIT is assembling machine code.
• c when running a Lua-C API call (typically into the LuaJIT runtime system.)
• exit when a trace exit handler is running.
• foreign when running machine code not assembled by the JIT (typically via FFI.)
• gc when garbage collecting.
• interp when interpreting Lua bytecodes.
• head when running JIT machine code that is not part of a trace loop.
• loop when running JIT machine code that is part of a trace loop.
• record when the JIT is recording a bytecode trace.

Timeline

Breaths efficiency

Callback efficiency