Re: Struct is slow

Sylvain Joyeux wrote:
I'm not sure whether you are familiar with Benchmark#bmbm which does a
rehearsal - personally I rather not switch off GC since in realistic
situations GC time belongs into the mix. But results are rather
similar:
Sure. GC does belong to the mix. Now, if GC is enabled you are not able to compare anything. Let's assume that GC runs during 'array init', you will say 'hey, struct init is faster'. Now, if GC runs during 'struct init' the result may change ...

Keeping GC is meaningful when benchmarking a whole application. In microbenchmarks like these, it is simply noise.

For fairness, you could do it this way (assuming REP is large enough):

...
Benchmark.bmbm 15 do |x|
GC.start
x.report 'struct init' do
REP.times { Foo.new data, data }
GC.start
end

GC.start
x.report 'array init' do
REP.times { [data, data] }
GC.start
end
...

--
vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

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Relevant Pages

  • Re: Struct is slow
    ... rehearsal - personally I rather not switch off GC since in realistic ... situations GC time belongs into the mix. ... if GC runs during 'struct init' the ... microbenchmarks like these, it is simply noise. ...
    (comp.lang.ruby)
  • Re: Struct is slow
    ... situations GC time belongs into the mix. ... if GC runs during 'struct init' the ... if you allocate a lot of memory ... IMHO cost of memory GC overhead is also part of the runtime ...
    (comp.lang.ruby)
  • Re: Struct is slow
    ... situations GC time belongs into the mix. ... if GC runs during 'struct init' the ... IMHO cost of memory GC overhead is also part of the runtime ...
    (comp.lang.ruby)