Skip to content
C Ruby
Find file
Pull request Compare This branch is 53 commits behind master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.


google-perftools for ruby code
  (c) 2009 Aman Gupta (tmm1)

=== Usage

  Run the profiler with a block:

    require 'perftools'
    PerfTools::CpuProfiler.start("/tmp/add_numbers_profile") do
      5_000_000.times{ 1+2+3+4+5 }

  Start and stop the profiler manually:

    require 'perftools'
    5_000_000.times{ 1+2+3+4+5 }

  Profile an existing ruby application without modifying it:

    $ CPUPROFILE=/tmp/my_app_profile RUBYOPT="-r`gem which perftools | tail -1`" ruby my_app.rb

  Change the sampling interval (defaults to 100 times a second, valid range is 1-4000):

    $ CPUPROFILE_FREQUENCY=500 ruby my_app.rb

  Use walltime instead of cputime profiling:

    $ CPUPROFILE_REALTIME=1 ruby my_app.rb

  Profile object allocations instead of cpu/wall time:

    $ CPUPROFILE_OBJECTS=1 ruby my_app.rb

  Profile method calls:

    $ CPUPROFILE_METHODS=1 ruby my_app.rb

=== Reporting

  pprof.rb --text /tmp/add_numbers_profile

  pprof.rb --pdf /tmp/add_numbers_profile > /tmp/add_numbers_profile.pdf

  pprof.rb --gif /tmp/add_numbers_profile > /tmp/add_numbers_profile.gif

  pprof.rb --callgrind /tmp/add_numbers_profile > /tmp/add_numbers_profile.grind
  kcachegrind /tmp/add_numbers_profile.grind

  pprof.rb --gif --focus=Integer /tmp/add_numbers_profile > /tmp/add_numbers_custom.gif

  pprof.rb --text --ignore=Gem /tmp/my_app_profile

  For more options, see

=== Examples

  pprof.rb --text

    Total: 1735 samples
        1487  85.7%  85.7%     1735 100.0% Integer#times
         248  14.3% 100.0%      248  14.3% Fixnum#+

  pprof.rb --gif

    Simple require 'rubygems' profile

    Comparing redis-rb with and without SystemTimer based socket timeouts

    Sinatra vs. Merb vs. Rails

    C-level profile of EventMachine + epoll + Ruby threads

    C-level profile of the ruby interpreter
      12% time spent in re_match_exec because of excessive calls to rb_str_sub_bang by Date.parse
      easily fixed by using the ThirdBase gem

=== Installation

  Just install the gem, which will download, patch and compile google-perftools for you:

    sudo gem install perftools.rb

  Or use the dev gem from github:

    gem install -s tmm1-perftools.rb

  Or build your own gem:

    git clone git://
    cd perftools.rb
    gem build perftools.rb.gemspec
    gem install perftools.rb

  You'll also need graphviz to generate call graphs using dot:

    sudo port install graphviz     # osx
    sudo apt-get install graphviz  # debian/ubuntu

=== Advantages over ruby-prof

  Sampling profiler

    perftools samples your process using setitimer() so it can be used in production with minimal overhead.

=== Profiling the Ruby VM and C extensions

  To profile C code, download and build an unpatched perftools (libunwind or ./configure --enable-frame-pointers required on x86_64):

    tar zxvf google-perftools-1.3.tar.gz
    cd google-perftools-1.3

    ./configure --prefix=/opt
    sudo make install

    export LD_PRELOAD=/opt/lib/                 # for linux
    export DYLD_INSERT_LIBRARIES=/opt/lib/libprofiler.dylib   # for osx
    CPUPROFILE=/tmp/ruby_interpreter.profile ruby -e' 5_000_000.times{ "hello world" } '

    pprof `which ruby` --text /tmp/ruby_interpreter.profile

=== TODO

  * Add support for heap profiling to find memory leaks (PerfTools::HeapProfiler)
  * Allow both C and Ruby profiling
  * Add setter for the sampling interval

=== Resources

  GoRuCo 2009 Lightning Talk on perftools.rb at 21:52

  Ilya Grigorik's introduction to perftools.rb

  Google Perftools

  Analyzing profiles and interpreting different output formats
Something went wrong with that request. Please try again.