[Gems-users] R: Comparing "ruby cycles" when running ruby alone and opal+ruby

["Alessandro Bardine" <alessandro.bardine@xxxxxxxxxxxx>]

Dan,
very thank you for your replies.
At this point I have another question:
The performances of the L2 cache in the two enviroments (in terms of
miss-rates) should be the same?
I think yes because, apart of different timing scales, in both enviroments I
should have (almost) the same requests to the L2.
 
> 
> Alessandro Bardine wrote:
> 
> >Hi,
> >I am trying to compare the ruby cycles value that I get
> >when I run a benchmark in opal+ruby environment ( with DNUCA cache
> >architecture) with the same value that I get when I only run ruby (with
> the
> >same DNUCA cache) driven directly by Simics.
> >My idea is to make a comparison for the "ruby cycles" values I get at
> some
> >fixed number of executed instruction in both environments.
> >To do this I step opal+ruby with the "sim-step" command and I collect the
> >ruby cicle value at regular interval, while for ruby alone I collect info
> >from the file generated with the "periodical-stat-file".
> >
> >What I expected was to get similar results but what I am getting from the
> >first simulations is quite different!!
> >
> >
> I would expect the value of ruby_cycles to vary greatly between
> Ruby-only and Opal+Ruby configurations. When Opal is NOT loaded, the
> processor model is that of an in-order, blocking machine. Opal simulates
> an out-of-order machine, and thus should behave very differently from
> (and probably perform better than) the Ruby-only configuration.
> 
> >Are the values of "ruby-cycles" for the two environments (intended at the
> >same number of total executed instruction) directly comparable?
> >
> >
> The two values will show the performance of an in-order core for
> Ruby-only, and the performance of an out-of-order core for Opal+Ruby.
> They both are a measure of "execution time".
> 
> >For the "ruby alone" I get the number of executed instruction in the
> file
> >generated with the "periodical-stat-file", what is hard to understand for
> me
> >is how ruby is able to know this value assumed that it is being driven by
> >Simics.
> >
> >
> >
> Ruby is aware of the number of instructions executed through the Simics
> API. That is, it is possible to simply ask Simics how many instructions
> have been executed on a given processor. See the Simics documentation
> (specifically, the Simics reference manual) for more information.
> 
> Regards,
> Dan Gibson
> 
> >
> >
> >_______________________________________________
> >Gems-users mailing list
> >Gems-users@xxxxxxxxxxx
> >https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> >
> >
> >
> _______________________________________________
> Gems-users mailing list
> Gems-users@xxxxxxxxxxx
> https://lists.cs.wisc.edu/mailman/listinfo/gems-users