Benchmark setup, 56s for 1.9.3, 50s for 2.0.0

myapp/app/workers/lazy_worker.rb

@@ -0,0 +1,6 @@
+class LazyWorker
+  include Sidekiq::Worker
+
+  def perform
+  end
+end

myapp/bench.rb

@@ -0,0 +1,11 @@
+require 'sidekiq'
+
+Sidekiq.configure_client do |config|
+  config.redis = { :namespace => 'foo' }
+end
+
+jobs = []
+20_000.times do
+  jobs << []
+end
+Sidekiq::Client.push_bulk 'class' => 'LazyWorker', 'args' => jobs