This is a tiny adaptation of the cluster example at http://nodejs.org/api/cluster.html to illustrate the problem i'm seeing in https://github.com/joyent/node/issues/3241

test.js

// a tiny adaptation of the cluster example at http://nodejs.org/api/cluster.html
// 1. save as test.js
// 2. run with "./node test.js > pid.log"
// 3. from another shell do "siege -t1m -c 50 http://localhost:8000"
// 5. wait for the siege to finish
// 6. ctrl-c the node process
// 7. sort pid.log | uniq -c

// The left side is # of requests served, the right side is pid. 
// If it's balanced (as it is for me on the 2.6.32 linux kernel) then yay! 
// If it's nowhere near balanced (as it is for me on the the 3.2.0 linux kernel) then oh no!

var cluster = require('cluster');
var http = require('http');
var numCPUs = Math.max(1, Math.floor(require('os').cpus().length / 2));

if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

  cluster.on('exit', function(worker, code, signal) {
    console.log('worker ' + worker.process.pid + ' died');
  });
} else {
  // Workers can share any TCP connection
  // In this case its a HTTP server
  http.createServer(function(req, res) {
    res.writeHead(200);
    res.end("hello world from pid " + process.pid + "\n");
    console.log(process.pid);
  }).listen(8000);