Investigate flaky parallel/test-performance #19197

assert.js:249
    throw err;
    ^

AssertionError [ERR_ASSERTION]: The expression evaluated to a falsy value:

  assert(Math.abs(delta) < 1000)

    at checkNodeTiming (/home/iojs/build/workspace/node-test-commit-aix/nodes/aix61-ppc64/test/parallel/test-performance.js:118:7)
    at Object.<anonymous> (/home/iojs/build/workspace/node-test-commit-aix/nodes/aix61-ppc64/test/parallel/test-performance.js:125:1)
    at Module._compile (module.js:670:30)
    at Object.Module._extensions..js (module.js:681:10)
    at Module.load (module.js:581:32)
    at tryModuleLoad (module.js:521:12)
    at Function.Module._load (module.js:513:3)
    at Function.Module.runMain (module.js:711:10)
    at startup (bootstrap_node.js:223:16)
    at bootstrapNodeJSCore (bootstrap_node.js:562:3)