ruby/benchmark
eileencodes e8ae922b62 Add a cache for class variables
This change implements a cache for class variables. Previously there was
no cache for cvars. Cvar access is slow due to needing to travel all the
way up th ancestor tree before returning the cvar value. The deeper the
ancestor tree the slower cvar access will be.

The benefits of the cache are more visible with a higher number of
included modules due to the way Ruby looks up class variables. The
benchmark here includes 26 modules and shows with the cache, this branch
is 6.5x faster when accessing class variables.

```
compare-ruby: ruby 3.1.0dev (2021-03-15T06:22:34Z master 9e5105ca45) [x86_64-darwin19]
built-ruby: ruby 3.1.0dev (2021-03-15T12:12:44Z add-cache-for-clas.. c6be0093ae) [x86_64-darwin19]

|         |compare-ruby|built-ruby|
|:--------|-----------:|---------:|
|vm_cvar  |      5.681M|   36.980M|
|         |           -|     6.51x|
```

Benchmark.ips calling `ActiveRecord::Base.logger` from within a Rails
application. ActiveRecord::Base.logger has 71 ancestors. The more
ancestors a tree has, the more clear the speed increase. IE if Base had
only one ancestor we'd see no improvement. This benchmark is run on a
vanilla Rails application.

Benchmark code:

```ruby
require "benchmark/ips"
require_relative "config/environment"

Benchmark.ips do |x|
  x.report "logger" do
    ActiveRecord::Base.logger
  end
end
```

Ruby 3.0 master / Rails 6.1:

```
Warming up --------------------------------------
              logger   155.251k i/100ms
Calculating -------------------------------------
```

Ruby 3.0 with cvar cache /  Rails 6.1:

```
Warming up --------------------------------------
              logger     1.546M i/100ms
Calculating -------------------------------------
              logger     14.857M (± 4.8%) i/s -     74.198M in   5.006202s
```

Lastly we ran a benchmark to demonstate the difference between master
and our cache when the number of modules increases. This benchmark
measures 1 ancestor, 30 ancestors, and 100 ancestors.

Ruby 3.0 master:

```
Warming up --------------------------------------
            1 module     1.231M i/100ms
          30 modules   432.020k i/100ms
         100 modules   145.399k i/100ms
Calculating -------------------------------------
            1 module     12.210M (± 2.1%) i/s -     61.553M in   5.043400s
          30 modules      4.354M (± 2.7%) i/s -     22.033M in   5.063839s
         100 modules      1.434M (± 2.9%) i/s -      7.270M in   5.072531s

Comparison:
            1 module: 12209958.3 i/s
          30 modules:  4354217.8 i/s - 2.80x  (± 0.00) slower
         100 modules:  1434447.3 i/s - 8.51x  (± 0.00) slower
```

Ruby 3.0 with cvar cache:

```
Warming up --------------------------------------
            1 module     1.641M i/100ms
          30 modules     1.655M i/100ms
         100 modules     1.620M i/100ms
Calculating -------------------------------------
            1 module     16.279M (± 3.8%) i/s -     82.038M in   5.046923s
          30 modules     15.891M (± 3.9%) i/s -     79.459M in   5.007958s
         100 modules     16.087M (± 3.6%) i/s -     81.005M in   5.041931s

Comparison:
            1 module: 16279458.0 i/s
         100 modules: 16087484.6 i/s - same-ish: difference falls within error
          30 modules: 15891406.2 i/s - same-ish: difference falls within error
```

Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>
2021-05-11 12:04:27 -07:00
..
2018-09-28 05:28:12 +00:00
2019-08-05 09:04:32 +09:00
2020-07-18 23:45:00 +09:00
2020-07-18 23:45:00 +09:00
2020-07-18 23:45:00 +09:00
2020-07-18 23:45:25 +09:00
2021-02-10 19:42:00 +09:00
2019-06-01 20:07:50 +09:00
2019-08-10 11:26:23 +09:00
2018-12-27 06:12:09 +00:00
2018-12-27 06:12:09 +00:00
2018-12-27 06:12:09 +00:00
2019-01-07 02:05:21 +00:00
2021-05-11 12:04:27 -07:00
2020-12-16 10:29:48 +09:00

ruby/benchmark

This directory has benchmark definitions to be run with benchmark_driver.gem.

Normal usage

Execute gem install benchmark_driver and run a command like:

# Run a benchmark script with the ruby in the $PATH
benchmark-driver benchmark/app_fib.rb

# Run benchmark scripts with multiple Ruby executables or options
benchmark-driver benchmark/*.rb -e /path/to/ruby -e '/path/to/ruby --jit'

# Or compare Ruby versions managed by rbenv
benchmark-driver benchmark/*.rb --rbenv '2.5.1;2.6.0-preview2 --jit'

# You can collect many metrics in many ways
benchmark-driver benchmark/*.rb --runner memory --output markdown

# Some are defined with YAML for complex setup or accurate measurement
benchmark-driver benchmark/*.yml

See also:

Usage: benchmark-driver [options] RUBY|YAML...
    -r, --runner TYPE                Specify runner type: ips, time, memory, once (default: ips)
    -o, --output TYPE                Specify output type: compare, simple, markdown, record (default: compare)
    -e, --executables EXECS          Ruby executables (e1::path1 arg1; e2::path2 arg2;...)
        --rbenv VERSIONS             Ruby executables in rbenv (x.x.x arg1;y.y.y arg2;...)
        --repeat-count NUM           Try benchmark NUM times and use the fastest result or the worst memory usage
        --repeat-result TYPE         Yield "best", "average" or "worst" result with --repeat-count (default: best)
        --bundler                    Install and use gems specified in Gemfile
        --filter REGEXP              Filter out benchmarks with given regexp
        --run-duration SECONDS       Warmup estimates loop_count to run for this duration (default: 3)
    -v, --verbose                    Verbose mode. Multiple -v options increase visibility (max: 2)

make benchmark

Using make benchmark, make update-benchmark-driver automatically downloads the supported version of benchmark_driver, and it runs benchmarks with the downloaded benchmark_driver.

# Run all benchmarks with the ruby in the $PATH and the built ruby
make benchmark

# Or compare with specific ruby binary
make benchmark COMPARE_RUBY="/path/to/ruby --jit"

# Run vm benchmarks
make benchmark ITEM=vm

# Run some limited benchmarks in ITEM-matched files
make benchmark ITEM=vm OPTS=--filter=block

# You can specify the benchmark by an exact filename instead of using the default argument:
# ARGS = $$(find $(srcdir)/benchmark -maxdepth 1 -name '*$(ITEM)*.yml' -o -name '*$(ITEM)*.rb')
make benchmark ARGS=benchmark/erb_render.yml

# You can specify any option via $OPTS
make benchmark OPTS="--help"

# With `make benchmark`, some special runner plugins are available:
#   -r peak, -r size, -r total, -r utime, -r stime, -r cutime, -r cstime
make benchmark ITEM=vm_bigarray OPTS="-r peak"