This heap emulates the growth characteristics of the Ruby default GC's
heap. By default, the heap grows by 40%, requires at least 20% empty
after a GC, and allows at most 65% empty before it shrinks the heap. This
is all configurable via the same environment variables the default GC
uses (`RUBY_GC_HEAP_FREE_SLOTS_GOAL_RATIO`, `RUBY_GC_HEAP_FREE_SLOTS_MIN_RATIO`,
`RUBY_GC_HEAP_FREE_SLOTS_MAX_RATIO`, respectively).
The Ruby heap can be enabled via the `MMTK_HEAP_MODE=ruby` environment
variable.
Compared to the dynamic heap in MMTk (which uses the MemBalancer algorithm),
the Ruby heap allows the heap to grow more generously, which uses a bit
more memory but offers significant performance gains because it runs GC
much less frequently.
We can see in the benchmarks below that this Ruby heap heap gives faster
performance than the dynamic heap in every benchmark, with over 2x faster
in many of them. We see that memory is often around 10-20% higher with
certain outliers that use significantly more memory like hexapdf and
erubi-rails. We can also see that this brings MMTk's Ruby heap much
closer in performance to the default GC.
Ruby heap benchmark results:
-------------- -------------- ---------- ---------
bench ruby heap (ms) stddev (%) RSS (MiB)
activerecord 233.6 10.7 85.9
chunky-png 457.1 1.1 79.3
erubi-rails 1148.0 3.8 133.3
hexapdf 1570.5 2.4 403.0
liquid-c 42.8 5.3 43.4
liquid-compile 41.3 7.6 52.6
liquid-render 102.8 3.8 55.3
lobsters 651.9 8.0 426.3
mail 106.4 1.8 67.2
psych-load 1552.1 0.8 43.4
railsbench 1707.2 6.0 145.6
rubocop 127.2 15.3 148.8
ruby-lsp 136.6 11.7 113.7
sequel 47.2 5.9 44.4
shipit 1197.5 3.6 301.0
-------------- -------------- ---------- ---------
Dynamic heap benchmark results:
-------------- ----------------- ---------- ---------
bench dynamic heap (ms) stddev (%) RSS (MiB)
activerecord 845.3 3.1 76.7
chunky-png 525.9 0.4 38.9
erubi-rails 2694.9 3.4 115.8
hexapdf 2344.8 5.6 164.9
liquid-c 73.7 5.0 40.5
liquid-compile 107.1 6.8 40.3
liquid-render 147.2 1.7 39.5
lobsters 697.6 4.5 342.0
mail 224.6 2.1 64.0
psych-load 4326.7 0.6 37.4
railsbench 3218.0 5.5 124.7
rubocop 203.6 6.1 110.9
ruby-lsp 350.7 3.2 79.0
sequel 121.8 2.5 39.6
shipit 1510.1 3.1 220.8
-------------- ----------------- ---------- ---------
Default GC benchmark results:
-------------- --------------- ---------- ---------
bench default GC (ms) stddev (%) RSS (MiB)
activerecord 148.4 0.6 67.9
chunky-png 440.2 0.7 57.0
erubi-rails 722.7 0.3 97.8
hexapdf 1466.2 1.7 254.3
liquid-c 32.5 3.6 42.3
liquid-compile 31.2 1.9 35.4
liquid-render 88.3 0.7 30.8
lobsters 633.6 7.0 305.4
mail 76.6 1.6 53.2
psych-load 1166.2 1.3 29.1
railsbench 1262.9 2.3 114.7
rubocop 105.6 0.8 95.4
ruby-lsp 101.6 1.4 75.4
sequel 27.4 1.2 33.1
shipit 1083.1 1.5 163.4
-------------- --------------- ---------- ---------
https://github.com/ruby/mmtk/commit/c0ca29922d
What is Ruby?
Ruby is an interpreted object-oriented programming language often used for web development. It also offers many scripting features to process plain text and serialized files, or manage system tasks. It is simple, straightforward, and extensible.
Features of Ruby
- Simple Syntax
- Normal Object-oriented Features (e.g. class, method calls)
- Advanced Object-oriented Features (e.g. mix-in, singleton-method)
- Operator Overloading
- Exception Handling
- Iterators and Closures
- Garbage Collection
- Dynamic Loading of Object Files (on some architectures)
- Highly Portable (works on many Unix-like/POSIX compatible platforms as well as Windows, macOS, etc.) cf. https://docs.ruby-lang.org/en/master/maintainers_md.html#label-Platform+Maintainers
How to get Ruby
For a complete list of ways to install Ruby, including using third-party tools like rvm, see:
https://www.ruby-lang.org/en/downloads/
You can download release packages and the snapshot of the repository. If you want to download whole versions of Ruby, please visit https://www.ruby-lang.org/en/downloads/releases/.
Download with Git
The mirror of the Ruby source tree can be checked out with the following command:
$ git clone https://github.com/ruby/ruby.git
There are some other branches under development. Try the following command to see the list of branches:
$ git ls-remote https://github.com/ruby/ruby.git
You may also want to use https://git.ruby-lang.org/ruby.git (actual master of Ruby source) if you are a committer.
How to build
See Building Ruby
Ruby home page
Documentation
Mailing list
There is a mailing list to discuss Ruby. To subscribe to this list, please send the following phrase:
join
in the mail subject (not body) to the address ruby-talk-request@ml.ruby-lang.org.
Copying
See the file COPYING.
Feedback
Questions about the Ruby language can be asked on the Ruby-Talk mailing list or on websites like https://stackoverflow.com.
Bugs should be reported at https://bugs.ruby-lang.org. Read "Reporting Issues" for more information.
Contributing
See "Contributing to Ruby", which includes setup and build instructions.
The Author
Ruby was originally designed and developed by Yukihiro Matsumoto (Matz) in 1995.