Benchmark initializer load time

initializable.rb

# place in railties/lib/rails/initializable.rb

def run_initializers(group=:default, *args)
  return if instance_variable_defined?(:@ran)
  t0 = Time.now
  initializers.tsort.each do |initializer|
    t = Time.now
    initializer.run(*args) if initializer.belongs_to?(group)
    puts("%60s: %.3f sec" % [initializer.name, Time.now - t])
  end
  puts "%60s: %.3f sec" % ["for all", Time.now - t0]
  @ran = true
end