From: Xavier Shay Date: 2011-05-20T19:28:32+09:00 Subject: [ruby-core:36353] [Ruby 1.9 - Bug #3924] Performance bug (in require?) Issue #3924 has been updated by Xavier Shay. Progress update: Fixed the autoload problem, my fork now loads a moderate sized rails app in the same time as ruby 1.9.2 (and far faster that 1.9.3dev 20s compared to 46s), as well as passing all other tests/specs. This proves the algorithm I think, the next step is to optimize the inner functions (such as rb_locate_file_with_extensions), since they still use plenty of rb_funcall to do string manipulation which could be far faster done in C. There is also room for improvement by caching rb_locate_file. Code is still at https://github.com/xaviershay/ruby/tree/require-performance-fix I hope to have more time to work on it on Sunday. ---------------------------------------- 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