‘gem install ruby-prof` then add ?profile=process_time to any URL to profile the page load and download a calltree file. Open it with kcachegrind.
Add an around_filter :action_profiler to ApplicationController:
around_filter :action_profiler unless Rails.env.production?
Enable live profiling in production accessible to specific IP addresses:
ALLOWED_IPS = ['127.0.0.1', '1.2.3.4'] around_filter :action_profiler, :if => lambda { |c| ALLOWED_IPS.include?(c.request.remote_ip) }
If you’re using Ruby Enterprise Edition or a patched Ruby 1.8, you can profile memory and object allocation also: ?profile=memory or allocations.
This plugin uses an around_filter to profile the controller action only. Rack::Profiler, part of rack-contrib, can profile the entire Rails request.
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