# Multi-cpu and ruby Threading **URL:** \ **Category:** Ruby\ **Created:** [June 29, 2010, 4:52pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865 "2010-06-29T16:52:05Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![raubarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@raubarede](https://www.ruby-forum.com/u/raubarede)\ **Post date:** [June 29, 2010, 4:52pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865/1 "2010-06-29T16:52:05Z")
Hello, We receive a new PC based on I Core 7 on Windows 7. So i try to compare the use processors resources of each Ruby interpretor (JRuby,IronRuby,Ruby 1.9.1 ). I do the same (stupid) treatment by 1 to 8 threads, and measure the global duration. (test program is on attachment) Here is the result. c:\usr\ruby\local\>jruby thread\_bench.rb 1.8.7, java, 2010-05-12 1000 iterations by 1 threads , Duration = 2772 ms 500 iterations by 2 threads , Duration = 2076 ms 333 iterations by 3 threads , Duration = 1884 ms 250 iterations by 4 threads , Duration = 1848 ms 200 iterations by 5 threads , Duration = 1814 ms 166 iterations by 6 threads , Duration = 1755 ms 142 iterations by 7 threads , Duration = 1866 ms 125 iterations by 8 threads , Duration = 1538 ms c:\usr\ruby\local\>ir thread\_bench.rb 1.8.6, i386-mswin32, 2009-03-31 1000 iterations by 1 threads , Duration = 2257 ms 500 iterations by 2 threads , Duration = 1305 ms 333 iterations by 3 threads , Duration = 1055 ms 250 iterations by 4 threads , Duration = 880 ms 200 iterations by 5 threads , Duration = 1026 ms 166 iterations by 6 threads , Duration = 940 ms 142 iterations by 7 threads , Duration = 989 ms 125 iterations by 8 threads , Duration = 1098 ms c:\usr\ruby\local\>ruby19 thread\_bench.rb 1.9.1, i386-mswin32, 2010-01-10 1000 iterations by 1 threads , Duration = 7318 ms 500 iterations by 2 threads , Duration = 7393 ms 333 iterations by 3 threads , Duration = 7335 ms 250 iterations by 4 threads , Duration = 7367 ms 200 iterations by 5 threads , Duration = 7450 ms 166 iterations by 6 threads , Duration = 7343 ms 142 iterations by 7 threads , Duration = 7349 ms 125 iterations by 8 threads , Duration = 7454 ms So it’s seem that IronRuby has better use of cpus than JRuby ? ---
**Author:** ![raubarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@raubarede](https://www.ruby-forum.com/u/raubarede)\ **Post date:** [June 29, 2010, 5:07pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865/2 "2010-06-29T17:07:48Z")
> So it’s seem that IronRuby has better use of cpus than JRuby ? I’ve seen a bit of slowdown on jruby when using multiple threads, as well. refs: [http://www.ruby-forum.com/topic/211415#new](http://www.ruby-forum.com/topic/211415#new) [http://en.wikibooks.org/wiki/Ruby\_Programming/Reference/Objects/Thread](http://en.wikibooks.org/wiki/Ruby_Programming/Reference/Objects/Thread) ---
**Author:** ![raubarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@raubarede](https://www.ruby-forum.com/u/raubarede)\ **Post date:** [June 29, 2010, 6:15pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865/3 "2010-06-29T18:15:39Z")
Roger P. wrote: > I’ve seen a bit of slowdown on jruby when using multiple threads, as > well. Result seem different on Linux.Here same test, on same machine, on ubunbtu 10.4/virtualbox with 8 processor affinity ; regis@regis-desktop:~/Ruby/local$ java -version java version “1.6.0\_18” OpenJDK Runtime Environment (IcedTea6 1.8) (6b18-1.8-0ubuntu1) OpenJDK Server VM (build 14.0-b16, mixed mode) regis@regis-desktop:~/Ruby/local$ jruby -v jruby 1.5.1 (ruby 1.8.7 patchlevel 249) (2010-06-06 f3a3480) (OpenJDK Client VM 1.6.0\_18) [i386-java] regis@regis-desktop:~/Ruby/local$ jruby thread\_bench.rb 1.8.7, java, 2010-06-06 1000 iterations by 1 threads , Duration = 3930 ms 500 iterations by 2 threads , Duration = 3723 ms 333 iterations by 3 threads , Duration = 3490 ms 250 iterations by 4 threads , Duration = 3470 ms 200 iterations by 5 threads , Duration = 3353 ms 166 iterations by 6 threads , Duration = 3378 ms 142 iterations by 7 threads , Duration = 3455 ms 125 iterations by 8 threads , Duration = 4032 ms regis@regis-desktop:~/Ruby/local$ ir -v IronRuby 0.9.0.0 on .NET 2.0.0.0 regis@regis-desktop:~/Ruby/local$ ir thread\_bench.rb 1.8.6, i386-mswin32, 2008-05-28 1000 iterations by 1 threads , Duration = 11091 ms 500 iterations by 2 threads , Duration = 7676 ms 333 iterations by 3 threads , Duration = 12243 ms 250 iterations by 4 threads , Duration = 7728 ms 200 iterations by 5 threads , Duration = 7767 ms 166 iterations by 6 threads , Duration = 7749 ms 142 iterations by 7 threads , Duration = 8184 ms 125 iterations by 8 threads , Duration = 8069 ms regis@regis-desktop:~/Ruby/local$ ---
**Author:** ![raubarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@raubarede](https://www.ruby-forum.com/u/raubarede)\ **Post date:** [June 29, 2010, 10:24pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865/4 "2010-06-29T22:24:06Z")
On Tue, Jun 29, 2010 at 9:52 AM, Regis d’Aubarede [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Here is the result. > 125 iterations by 8 threads  , Duration  = 1538 ms > Probably not running server VM, so pass --server. Overall times should > be better, but depending on the algorithm the remaining bottleneck for > JRuby may or may not be CPU-bound. The initial iteration’s time should probably be largely discounted, and the whole thing should probably be run a couple times to see the actual perf of a longer-running app. I don’t have IronRuby here, but here’s numbers for me on Java 6, server, OS X, Core 2 Duo 2.6GHz: (2nd time through in the same script, only the 1 and 2 processor runs): 1000 iterations by 1 threads , Duration = 2633 ms 500 iterations by 2 threads , Duration = 1628 ms If with --server on your system JRuby’s still slower than IronRuby, there may be a bug or bottleneck we can repair. I have been meaning to make blocks faster in JRuby, but they still come with a higher cost than some other impls. - Charlie ---
**Author:** ![raubarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@raubarede](https://www.ruby-forum.com/u/raubarede)\ **Post date:** [June 29, 2010, 10:32pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865/5 "2010-06-29T22:32:53Z")
On Tue, Jun 29, 2010 at 3:23 PM, Charles Oliver N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > If with --server on your system JRuby’s still slower than IronRuby, > there may be a bug or bottleneck we can repair. I have been meaning to > make blocks faster in JRuby, but they still come with a higher cost > than some other impls. Maybe also worth showing an experimental dynopt flag for JRuby that seem to improve performance dramatically, but at a small cost of some Ruby semantics (backtraces get a little funky, for example): ~/projects/jruby âž” jruby --server -J-Djruby.compile.dynopt=true thread\_bench.rb 1.8.7, java, 2010-06-17 1000 iterations by 1 threads , Duration = 400 ms 500 iterations by 2 threads , Duration = 188 ms 333 iterations by 3 threads , Duration = 192 ms 250 iterations by 4 threads , Duration = 149 ms 200 iterations by 5 threads , Duration = 167 ms 166 iterations by 6 threads , Duration = 214 ms 142 iterations by 7 threads , Duration = 177 ms 125 iterations by 8 threads , Duration = 163 ms 1000 iterations by 1 threads , Duration = 265 ms 500 iterations by 2 threads , Duration = 160 ms 333 iterations by 3 threads , Duration = 186 ms 250 iterations by 4 threads , Duration = 148 ms 200 iterations by 5 threads , Duration = 159 ms 166 iterations by 6 threads , Duration = 151 ms 142 iterations by 7 threads , Duration = 150 ms 125 iterations by 8 threads , Duration = 171 ms … Hopefully I can land this in JRuby 1.6, but it’s on master now. - Charlie ---
**Author:** ![raubarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@raubarede](https://www.ruby-forum.com/u/raubarede)\ **Post date:** [June 30, 2010, 5:20pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865/6 "2010-06-30T17:20:33Z")
Charles Nutter wrote: > > If with --server on your system JRuby’s still slower than IronRuby,… > > Maybe also worth showing an experimental dynopt flag for JRuby that seem to > > improve performance … Sorry for my bad english !! My test consist to verify that symetric multi-core (SMP) is well use by the VM. In this aspect, pure performence is not important. the decrease of duration calculation with the increase off used threads is my concern. ([The Great Ruby Shootout (Windows Edition) | Programming Zen](http://programmingzen.com/2010/06/28/the-great-ruby-shootout-windows-edition/) show that JRuby is superior to IronRuby…) For discrimination if the issue is in JRuby side or in JVM side, i run same JRubyCode, but invoke a pure Java traitement : (1…nb\_threads).map { Thread.new() { Calc.calc(p1,n1) } } with class Calc { public static long calc(int a, int b) { long res=0; for (int i=0;i\jruby thread\_bench2.rb 1.8.7, java, 2010-05-12 1000 iterations by 1 threads , Duration = 15404 ms 500 iterations by 2 threads , Duration = 8147 ms 333 iterations by 3 threads , Duration = 5812 ms 250 iterations by 4 threads , Duration = 4690 ms 200 iterations by 5 threads , Duration = 4648 ms 166 iterations by 6 threads , Duration = 4749 ms 142 iterations by 7 threads , Duration = 4371 ms 125 iterations by 8 threads , Duration = 4222 ms So JVM scale right 🙂 And my intel core i7 has realy 4 core… ---
**Author:** ![raubarede](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/d07c76/32.png) [@raubarede](https://www.ruby-forum.com/u/raubarede)\ **Post date:** [June 30, 2010, 7:58pm UTC](https://www.ruby-forum.com/t/multi-cpu-and-ruby-threading/190865/7 "2010-06-30T19:58:57Z")
On Wed, Jun 30, 2010 at 10:20 AM, Regis d’Aubarede [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Â Â Â for (int j=0;j\ Â Â Â for (int k=0;k\<1000;k++) > Â Â Â res+=i+j+k; > Â Â return(res); > Â } > } Yes, this result is not surprising to me. In the original case, the benchmark suffers mostly from all the objects being created. For example: - All the numeric loops (in JRuby) create at least one new Fixnum object for every iteration - All the math operations create Fixnum or Float objects as well Running an allocation profile of your benchmark (which actually runs pretty slow because there’s _so much_ allocation happening) shows the amount of data that’s being chewed up…it’s very likely that the bottleneck is in allocating all those closures and all those Fixnums for this particular case: ~/projects/jruby âž” jruby -J-Xrunhprof thread\_bench.rb 1.8.7, java, 2010-06-17 1000 iterations by 1 threads , Duration = 399267 ms ^CDumping Java heap … allocation sites … done. ~/projects/jruby âž” egrep “%|objs” java.hprof.txt | head -n 11 rank self accum bytes objs bytes objs trace name 1 65.18% 65.18% 13545024 423282 1133938432 35435576 302318 org.jruby.RubyFixnum 2 22.61% 87.79% 4697920 146810 381348672 11917146 302867 org.jruby.RubyFloat 3 1.32% 89.12% 274992 5350 274992 5350 300000 char[] 4 0.62% 89.74% 128488 5341 128488 5341 300000 java.lang.String 5 0.18% 89.92% 38184 1 38184 1 306423 short[] 6 0.18% 90.10% 38184 1 38184 1 306428 short[] 7 0.14% 90.24% 28720 718 29400 735 300521 java.util.WeakHashMap$Entry 8 0.13% 90.37% 27792 70 27792 70 300000 byte[] 9 0.13% 90.50% 26832 1118 35040 1460 300704 java.util.concurrent.ConcurrentHashMap$HashEntry 10 0.12% 90.63% 25232 166 25232 166 300557 org.jruby.MetaClass Note that this is only after the 1000-iteration run, and during execution over 1GB of memory was allocated and released, mostly in Fixnum objects with a smaller amount (380MB+) in Float objects. Running with verbose GC: ~/projects/jruby âž” jruby -J-verbose:gc thread\_bench.rb 1.8.7, java, 2010-06-17 [GC 13184K-\>1128K(63936K), 0.0108696 secs] [GC 14312K-\>2124K(63936K), 0.0077762 secs] [GC 15308K-\>1445K(63936K), 0.0010409 secs] [GC 14629K-\>1246K(63936K), 0.0031958 secs] … And adding up all the size changes (number of GC runs \* difference in live object size) produces roughly the same estimate; for the period the 1000-iteration part of the bench runs, it allocates a _lot_ of objects. IronRuby may do better here if they’re able to treat Fixnum objects as value types, which the CLR handles more efficiently than the JVM’s “every object is on the heap”. Ultimately this is largely an allocation-rate benchmark, at least on JRuby, since our Fixnum objects are “real” objects (or to put it in MRI’s favor…our Fixnum objects are forced to be “real” objects with heap lifecycles). The dynopt work is part of efforts in JRuby to bring math performance closer to Java, largely by eliminating te excessive object churn and layers of noise for math operations. - Charlie