From: ko1@... Date: 2021-01-05T08:08:54+00:00 Subject: [ruby-core:101931] [Ruby master Bug#17497] Ractor performance issue Issue #17497 has been updated by ko1 (Koichi Sasada). master_ruby and ruby was same, so not needed. with version information: ``` 26_mini ruby 2.6.7p148 (2020-06-14 revision 67884) [x86_64-linux] 27_mini ruby 2.7.3p139 (2020-10-11 revision d1ba554551) [x86_64-linux] miniruby ruby 3.1.0dev (2021-01-05T07:50:00Z master e91160f757) [x86_64-linux] 26_ruby ruby 2.6.7p148 (2020-06-14 revision 67884) [x86_64-linux] 27_ruby ruby 2.7.3p139 (2020-10-11 revision d1ba554551) [x86_64-linux] ruby ruby 3.1.0dev (2021-01-05T07:50:00Z master e91160f757) [x86_64-linux] method: task_range_inject user system total real serial/26_mini 0 0.000330 0.000000 1.334362 ( 1.334173) serial/27_mini 0 0.000401 0.000000 1.111259 ( 1.111157) serial/miniruby 0 0.000388 0.000000 1.803708 ( 1.803610) serial/26_ruby 0 0.000283 0.000000 1.274182 ( 1.274051) serial/27_ruby 0 0.000243 0.000000 1.102547 ( 1.102493) serial/ruby 0 0.000340 0.000000 1.892771 ( 1.892611) r_serial/26_mini N/A r_serial/27_mini N/A r_serial/miniruby 1 0.000271 0.000000 2.484844 ( 2.485867) r_serial/26_ruby N/A r_serial/27_ruby N/A r_serial/ruby 1 0.000308 0.000000 2.736252 ( 2.737059) r_parallel/26_mini N/A r_parallel/27_mini N/A r_parallel/miniruby 1 0.000232 0.000000 20.958254 ( 5.828039) r_parallel/26_ruby N/A r_parallel/27_ruby N/A r_parallel/ruby 1 0.000396 0.000000 22.323984 ( 6.165640) ``` ---------------------------------------- Bug #17497: Ractor performance issue https://bugs.ruby-lang.org/issues/17497#change-89779 * Author: marcandre (Marc-Andre Lafortune) * Status: Open * Priority: Normal * Assignee: ko1 (Koichi Sasada) * ruby -v: ruby 3.0.0p0 (2020-12-25 revision 95aff21468) [x86_64-darwin18] * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- There's a strange performance issue with Ractor (at least on MacOS, didn't run on other OS). I ran a benchmark doing 3 different types of work: * "fib": method calls (naive fibonacci calculation) * "cpu": `(0...1000).inject(:+)` * "sleep": call `sleep` I get the kind of results I was excepting for the `fib` and for sleeping, but the results for the "cpu" workload show a problem. It is so slow that my pure Ruby backport (using Threads) is 65x faster ���� on my Mac Pro (despite having 6 cores). Expected results would be 6x slower, so in that case Ractor is 400x slower than it should ���� On my MacBook (2 cores) the results are not as bad, the `cpu` workload is 3x faster with my pure-Ruby backport (only) instead of ~2x slower, so the factor is 6x too slow. ``` $ gem install backports Successfully installed backports-3.20.0 1 gem installed $ ruby ractor_test.rb :267: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues. fib: 110 ms | cpu: 22900 ms | sleep: 206 ms $ B=t ruby ractor_test.rb Using pure Ruby implementation fib: 652 ms | cpu: 337 ms | sleep: 209 ms ``` Notice the `sleep` run takes similar time, which is good, and `fib` is ~6x faster on my 6-core CPU (and ~2x faster on my 2-core MacBook), again that's good as the pure ruby version uses Threads and thus runs with a single GVL. The `cpu` version is the problem. Script is here: https://gist.github.com/marcandre/bfed626e538a3d0fc7cad38dc026cf0e -- https://bugs.ruby-lang.org/ Unsubscribe: