benchmark/benchmark.rb in asciidoctor-1.5.1 vs benchmark/benchmark.rb in asciidoctor-1.5.2

@@ -19,12 +19,14 @@
 
 .Ruby < 2.1
  $ RUBY_GC_MALLOC_LIMIT=90000000 RUBY_FREE_MIN=650000 ruby benchmark.rb userguide-loop 10
 
 .Ruby >= 2.1
- $ RUBY_GC_MALLOC_LIMIT=128000000 RUBY_GC_OLDMALLOC_LIMIT=128000000 RUBY_GC_HEAP_INIT_SLOTS=800000 RUBY_GC_HEAP_FREE_SLOTS=800000 RUBY_GC_HEAP_GROWTH_MAX_SLOTS=250000 RUBY_GC_HEAP_GROWTH_FACTOR=1.5 ruby benchmark.rb userguide-loop 10
+ $ RUBY_GC_MALLOC_LIMIT=128000000 RUBY_GC_OLDMALLOC_LIMIT=128000000 RUBY_GC_HEAP_INIT_SLOTS=800000 RUBY_GC_HEAP_FREE_SLOTS=800000 RUBY_GC_HEAP_GROWTH_MAX_SLOTS=250000 RUBY_GC_HEAP_GROWTH_FACTOR=2 ruby benchmark.rb userguide-loop 10
 
 Asciidoctor starts with ~ 12,500 objects, adds ~ 300,000 each run, so tune RUBY_GC_HEAP_* accordingly
+
+See http://globaldev.co.uk/2014/05/ruby-2-1-in-detail/#gc-tuning-environment-variables
 
 Execute Ruby using the `--disable=gems` flag to speed up the initial load time, as shown below:
 
  $ ruby --disable=gems ...