Awesome
yjit-bench
Small set of benchmarks and scripts for the YJIT Ruby JIT compiler project, which lives in the Shopify/yjit repository.
The benchmarks are found in the benchmarks
directory. Individual Ruby files
in benchmarks
are microbenchmarks. Subdirectories under benchmarks
are
larger macrobenchmarks. Each benchmark relies on a harness found in
./harness/harness.rb. The harness controls the number of times a benchmark is
run, and writes timing values into an output file.
The run_benchmarks.rb
script (optional) traverses the benchmarks
directory and
runs the benchmarks in there. It reads the
output file written by the benchmarking harness. The output is written to
multiple files at the end -- CSV, text and JSON -- so that results can be easily viewed or
graphed in any spreadsheet editor.
Installation
Clone this repository:
git clone https://github.com/Shopify/yjit-bench.git yjit-bench
Benchmarking YJIT
yjit-bench supports benchmarking any Ruby implementation. But if you want to benchmark YJIT, follow these instructions to build and install YJIT.
If you install it with the name ruby-yjit
on chruby,
you should enable it before running ./run_benchmarks.rb
:
chruby ruby-yjit
Usage
To run all the benchmarks and record the data:
cd yjit-bench
./run_benchmarks.rb
This runs for a few minutes and produces a table like this in the console (results below not up to date):
------------- ----------- ---------- --------- ---------- ----------- ------------
bench interp (ms) stddev (%) yjit (ms) stddev (%) interp/yjit yjit 1st itr
30k_ifelse 2372.0 0.0 447.6 0.1 5.30 4.16
30k_methods 6328.3 0.0 963.4 0.0 6.57 6.25
activerecord 171.7 0.8 144.2 0.7 1.19 1.15
binarytrees 445.8 2.1 389.5 2.5 1.14 1.14
cfunc_itself 105.7 0.2 58.7 0.7 1.80 1.80
fannkuchredux 6697.3 0.1 6714.4 0.1 1.00 1.00
fib 245.3 0.1 77.1 0.4 3.18 3.19
getivar 97.3 0.9 44.3 0.6 2.19 0.98
lee 1269.7 0.9 1172.9 1.0 1.08 1.08
liquid-render 204.5 1.0 172.4 1.3 1.19 1.18
nbody 121.9 0.1 121.6 0.3 1.00 1.00
optcarrot 6260.2 0.5 4723.1 0.3 1.33 1.33
railsbench 3827.9 0.9 3581.3 1.3 1.07 1.05
respond_to 259.0 0.6 197.1 0.4 1.31 1.31
setivar 73.1 0.2 53.3 0.7 1.37 1.00
------------- ----------- ---------- --------- ---------- ----------- ------------
The interp/yjit
column is the ratio of the average time taken by the interpreter over the
average time taken by YJIT after a number of warmup iterations. Results above 1 represent
speedups. For instance, 1.14 means "YJIT is 1.14 times as fast as the interpreter".
Specific categories
By default, run_benchmarks.rb
runs all three benchmark categories,
--category headline,other,micro
. You can run only benchmarks with specific categories:
./run_benchmarks.rb --category micro
You can also only the headline benchmarks with the --headline
option:
./run_benchmarks.rb --headline
Specific benchmarks
To run one or more specific benchmarks and record the data:
./run_benchmarks.rb fib lee optcarrot
Running a single benchmark
This is the easiest way to run a single benchmark. It requires no setup at all and assumes nothing about the Ruby you are benchmarking. It's also convenient for profiling, debugging, etc, especially since all benchmarked code runs in that process.
ruby benchmarks/some_benchmark.rb
Ruby options
By default, yjit-bench benchmarks the Ruby used for run_benchmarks.rb
.
If the Ruby has --yjit
option, it compares two Ruby commands, -e "interp::ruby"
and -e "yjit::ruby --yjit
.
However, if you specify -e
yourself, you can override what Ruby is benchmarked.
# "xxx::" prefix can be used to specify a shorter name/alias, but it's optional.
./run_benchmarks.rb -e "ruby" -e "yjit::ruby --yjit"
# You could also measure only a single Ruby
./run_benchmarks.rb -e "3.1.0::/opt/rubies/3.1.0/bin/ruby"
# With --chruby, you can easily specify rubies managed by chruby
./run_benchmarks.rb --chruby "3.1.0" --chruby "3.1.0+YJIT::3.1.0 --yjit"
# ";" can be used to specify multiple executables in a single option
./run_benchmarks.rb --chruby "3.1.0;3.1.0+YJIT::3.1.0 --yjit"
YJIT options
You can use --yjit_opts
to specify YJIT command-line options:
./run_benchmarks.rb --yjit_opts="--yjit-version-limit=10" fib lee optcarrot
Running pre-init code
It is possible to use run_benchmarks.rb
to run arbitrary code before
each benchmark run using the --with-pre-init
option.
For example: to run benchmarks with GC.auto_compact
enabled a
pre-init.rb
file can be created, containing GC.auto_compact=true
,
and this can be passed into the benchmarks in the following way:
./run_benchmarks.rb --with-pre-init=./pre-init.rb
This file will then be passed to the underlying Ruby interpreter with
-r
.
Harnesses
You can find several test harnesses in this repository:
- harness - the normal default harness, with duration controlled by warmup iterations and time/count limits
- harness-bips - a harness that measures iterations/second until stable
- harness-continuous - a harness that adjusts the batch sizes of iterations to run in stable iteration size batches
- harness-once - a simplified harness that simply runs once
- harness-perf - a simplified harness that runs for exactly the hinted number of iterations
- harness-stackprof - a harness to profile the benchmark with stackprof
- harness-stats - count method calls and loop iterations
- harness-vernier - a harness to profile the benchmark with vernier
- harness-warmup - a harness which runs as long as needed to find warmed up (peak) performance
To use it, run a benchmark script directly, specifying a harness directory with -I
:
ruby -Iharness benchmarks/railsbench/benchmark.rb
There is also a robust but complex CI harness in the yjit-metrics repo.
Iterations and duration
With the default harness, the number of iterations and duration can be controlled by the following environment variables:
WARMUP_ITRS
: The number of warm-up iterations, ignored in the final comparison (default: 15)MIN_BENCH_ITRS
: The minimum number of benchmark iterations (default: 10)MIN_BENCH_TIME
: The minimum seconds for benchmark (default: 10)
You can also use --warmup
, --bench
, or --once
to set these environment variables:
# same as: WARMUP_ITRS=2 MIN_BENCH_ITRS=3 MIN_BENCH_TIME=0 ./run_benchmarks.rb railsbench
./run_benchmarks.rb railsbench --warmup=2 --bench=3
# same as: WARMUP_ITRS=0 MIN_BENCH_ITRS=1 MIN_BENCH_TIME=0 ./run_benchmarks.rb railsbench
./run_benchmarks.rb railsbench --once
There is also a handy script for running benchmarks just once using
WARMUP_ITRS=0 MIN_BENCH_ITRS=1 MIN_BENCH_TIME=0
, for example
with the --yjit-stats
command-line option:
./run_once.sh --yjit-stats benchmarks/railsbench/benchmark.rb
Using perf
There is also a harness to use Linux perf. By default, it only runs a fixed number of iterations.
If PERF
environment variable is present, it starts the perf subcommand after warmup.
# Use `perf record` for both warmup and benchmark
perf record ruby --yjit-perf=map -Iharness-perf benchmarks/railsbench/benchmark.rb
# Use `perf record` only for benchmark
PERF=record ruby --yjit-perf=map -Iharness-perf benchmarks/railsbench/benchmark.rb
This is the only harness that uses run_benchmark
's argument, num_itrs_hint
.
Measuring memory usage
--rss
option of run_benchmarks.rb
allows you to measure RSS after benchmark iterations.
./run_benchmarks.rb --rss
Rendering a graph
--graph
option of run_benchmarks.rb
allows you to render benchmark results as a graph.
# Write a graph at data/output_XXX.png (it will print the path)
./run_benchmarks.rb --graph
Installation
Before using this option, you might need to install the dependencies of Gruff:
# macOS
brew install imagemagick
# Ubuntu
sudo apt-get install libmagickwand-dev
Changing font size
You can regenerate a graph with misc/graph.rb
, changing its font size.
Usage: misc/graph.rb [options] CSV_PATH
--title SIZE title font size
--legend SIZE legend font size
--marker SIZE marker font size
Disabling CPU Frequency Scaling
To disable CPU frequency scaling with an Intel CPU, edit /etc/default/grub
or /etc/default/grub.d/50-cloudimg-settings.cfg
and add intel_pstate=no_hwp
to GRUB_CMDLINE_LINUX_DEFAULT
. It’s a space-separated list.
Then:
sudo update-grub
sudo reboot
sudo sh -c 'echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo'
To verify things worked:
cat /proc/cmdline
to see theintel_pstate=no_hwp
parameter is in therels /sys/devices/system/cpu/intel_pstate/
andhwp_dynamic_boost
should not existcat /sys/devices/system/cpu/intel_pstate/no_turbo
should say1
Helpful docs: