From: Chuck Remes <cremes.devlist@...>
Date: 2008-11-25T04:09:26+09:00
Subject: Re: Sieve of Zakiya


On Nov 24, 2008, at 11:25 AM, jzakiya wrote:

> On Nov 21, 1:31 am, Charles Oliver Nutter <charles.nut...@sun.com>
> wrote:
>> Charles Oliver Nutter wrote:
>>> brab...@gmail.com wrote:
>>>> $ jruby -J-Xmn128m -J-Xms1024m -J-Xmx1024m -J-server  
>>>> SieveOfZakiya.rb
>>
>>>> Error, could not compile; pass -d or
>>>> -J-Djruby.jit.logging.verbose=true for more details
>>
>>> Odd...the main script, or a method in it, must be gi-frigging- 
>>> gantic to
>>> blow out the bytecode cap. Glad to see in your results below that  
>>> with a
>>> bit of tweaking we're on par with 1.9. I'll look into the  
>>> compilation
>>> issue; I know there are a few cases that can still pop the compiler,
>>> like really big arrays that require a lot of init.
>>
>> Yeah, there's several methods there that could easily blow the cap  
>> and
>> have to remain interpreted. The inability to compile the whole file  
>> as a
>> result is probably a large part of the lower perf. The algorithm is  
>> also
>> *extremely* memory-intensive; logging GC on JRuby it had to do  
>> multiple
>> full collections before the first iteration even came back.
>>
>> - Charlie
>
> I just uploaded a more memory efficient and faster upgrade.
>
> Please check it out.

On a Mac Pro (2.8 Ghz). Jruby 1.1.5

cremes$  jruby -J-Xmn128m -J-Xms1024m -J-Xmx1024m -J-server  
SieveOfZakiya.rb
                     user     system      total        real
primes up to 10000001:   3.106000   0.000000   3.106000 (  3.105799)
primes up to 10000001:   5.774000   0.000000   5.774000 (  5.773820)
primes up to 10000001:   2.893000   0.000000   2.893000 (  2.893756)
primes up to 10000001:   7.883000   0.000000   7.883000 (  7.883993)
primes up to 10000001:   5.714000   0.000000   5.714000 (  5.714248)
primes up to 10000001:   4.792000   0.000000   4.792000 (  4.791677)
primes up to 10000001:   4.697000   0.000000   4.697000 (  4.697211)
primes up to 10000001:   4.066000   0.000000   4.066000 (  4.065598)
primes up to 10000001:   3.395000   0.000000   3.395000 (  3.394890)
primes up to 10000001:   3.232000   0.000000   3.232000 (  3.232953)
primes up to 10000001:   3.245000   0.000000   3.245000 (  3.244323)


Rubinius (built as of 5 minutes ago from latest git pull).

I cancelled the run after an hour. It had not yet completed a single  
run.

cr