From: "Jonas Pfenniger (zimbatm)" <jonas@...>
Date: 2011-01-09T08:07:26+09:00
Subject: [ruby-core:34262] Re: Avoiding $LOAD_PATH pollution

Just a note for future references. While playing with require, I found
that 1.9 was particularly slow on startups because of require. I
suspect it has something to do with the path expansions.

$ touch Gemfile
$ rvm use ruby-1.9.2
Using /Users/zimbatm/.rvm/gems/ruby-1.9.2-p136
$ RUBYOPT=-rprofile bundle install 2>&1 >/dev/null | head -n 6
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 43.04     1.02      1.02      197     5.18    31.98
Kernel.gem_original_require
 15.19     1.38      0.36    41288     0.01     0.01  Hash#default
  2.53     1.44      0.06     1546     0.04     0.05  Kernel.===
  1.69     1.48      0.04      171     0.23     2.22  Array#each

$ rvm use ruby-1.8.7
Using /Users/zimbatm/.rvm/gems/ruby-1.8.7-p330
$ RUBYOPT=-rprofile bundle install 2>&1 >/dev/null | head -n 6
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 13.71     0.24      0.24      168     1.43    17.26
Kernel.gem_original_require
  9.14     0.40      0.16      139     1.15     8.56  Array#each
  4.00     0.47      0.07     3229     0.02     0.02  Module#method_added
  3.43     0.53      0.06     2127     0.03     0.03  Module#===

$ rvm use ruby-1.9.2
Using /Users/zimbatm/.rvm/gems/ruby-1.9.2-p136
$ RUBYOPT=-rprofile rails help 2>&1 >/dev/null | head -n 6
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 34.25     0.75      0.75      156     4.81    45.45
Kernel.gem_original_require
  7.31     0.91      0.16      385     0.42     0.62  Array#include?
  6.85     1.06      0.15    25979     0.01     0.01  Hash#default
  5.48     1.18      0.12      298     0.40     1.41  Array#each

$ rvm use ruby-1.8.7
Using /Users/zimbatm/.rvm/gems/ruby-1.8.7-p330
$ RUBYOPT=-rprofile rails help 2>&1 >/dev/null | head -n 6
  %   cumulative   self              self     total
 time   seconds   seconds    calls  ms/call  ms/call  name
 12.50     0.30      0.30      142     2.11    35.21
Kernel.gem_original_require
  9.58     0.53      0.23      271     0.85     8.60  Array#each
  8.75     0.74      0.21     1892     0.11     0.18  Array#include?
  5.83     0.88      0.14     7964     0.02     0.02  String#==