Module phase_timer 

PMAT-284: Lightweight sub-phase timing for CPU-GPU pipelining analysis

PhaseTimer captures named sub-phases within a hot loop with minimal overhead when disabled. Designed for iteration-scheduler-level instrumentation where BrickProfiler (GPU-side) and InferenceTracer (model-level) don’t apply.

Usage

let mut timer = PhaseTimer::from_env("PMAT_283_TIMING");

loop {
    timer.start();
    timer.mark("lock");      // write lock acquired
    // ... scheduling ...
    timer.mark("sched");     // scheduling done
    // ... decode step ...
    timer.mark("decode");    // GPU decode done
    // ... token distribution ...
    timer.mark("dist");      // tokens distributed
    timer.emit(iteration, batch_size);  // prints if enabled + interval
}

Output: [PMAT-283] iter=42, m=4: lock=3µs sched=12µs decode=7412µs dist=84µs total=7511µs

Structs

PhaseTimer

Lightweight sub-phase timer for hot-path instrumentation.