From: Michael Genereux Date: 2011-05-16T07:31:14+09:00 Subject: [ruby-core:36208] [Ruby 1.9 - Bug #3924] Performance bug (in require?) Issue #3924 has been updated by Michael Genereux. Yes on the red herring of lstat. I removed the recursive lstat'ing (it's checking the path for symbolic links) and there was no speed increase. ---------------------------------------- Bug #3924: Performance bug (in require?) http://redmine.ruby-lang.org/issues/3924 Author: Carsten Bormann Status: Open Priority: Normal Assignee: Category: core Target version: 1.9.3 ruby -v: ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-darwin10] =begin Running irb < /dev/null in 1.9.2 causes 3016 calls to lstat64. For instance, there is a sequence of 28 repetitions each of lstat calls to all 6 non-empty path prefixes of /opt/local/lib/ruby1.9/1.9.1/irb.rb -- a total of 170 lstats apparently just to load this file; another set of lstats then occurs later for another 18 (times 6) times. Clearly, something is running amok in the calling sequence rb_require_safe -> realpath_rec -> lstat. Another example: Running a simple test with the baretest gem causes 17008 calls to lstat. According to perftools.rb, 80 % of the 1.2 seconds of CPU is used in Kernel#gem_original_require (and another 12 in GC, some of which may be caused by this). =end -- http://redmine.ruby-lang.org