$ node
> var PerfCounters = require('perf-counters');
> PerfCounters.init();
> var start = PerfCounters.getCounters(); console.log('test'); var end = PerfCounters.getCounters();
test
> start
{ instructions: 1382, loads: 421, stores: 309 }
> end
{ instructions: 647633, loads: 195771, stores: 133246 }
>