change_heap_limit.js

// $ node -v
// v8.4.0
// node --max-old-space-size=8192

"use strict";
var v8 = require("v8");
console.log(v8.getHeapStatistics());

// { total_heap_size: 9437184,
//   total_heap_size_executable: 3145728,
//   total_physical_size: 6571632,
//   total_available_size: 8612939144,
//   used_heap_size: 5360816,
//   heap_size_limit: 8623489024,
//   malloced_memory: 8192,
//   peak_malloced_memory: 5079792,
//   does_zap_garbage: 0 }