Re: [Gems-users] Different numbers of instructions, msgs, etc when running Ruby on the same workload

["Lide Duan" <leaderduan@xxxxxxxxx>]

Oh... so if some msgs finish their traverses more quickly due to the different routing algorithm, they might affect the following behaviors of the application, thus generating different amount of msgs in different runs, right? 

If so, how can I make a fair comparison between the performances using different routing algorithms? CPI?

Lide

On 11/1/07, Mike Marty < mikem@xxxxxxxxxxx> wrote:

If your routing algorithm changes the timing in any way, this can and
usually will affect the execution path of a multithreaded program

--Mike


Lide Duan wrote:
> Hello there,
>
> I have got some confusion about Ruby running on the same checkpoint...
>
> Basically I modified the routing algorithm utilized in the on-chip
> interconnect of Ruby, and compared the output results with the unmodified
> Ruby version. For both simulations, the checkpoint has been run from one
> magic instruction to the other, implying the same amount of work. I assumed
> that the msgs injected into the interconnect (from the components) should be
> the same for both cases because the only difference is the routing
> algorithm, which should not affect the behaviors on the cache level since
> all the msgs finally arrive to their corresponding destinations.
>
> However, the numbers of the injected msgs of the two runs have 5%
> difference, and the msgs generated in the interconnect (all of them are
> Invalidate_Control, to my observation) have more the 10% difference. The
> numbers of instructions of the two simulations are also different (but not
> much) although the two runs were from the same start point to the same end
> point.
>
> On the other hand, if I run Ruby twice without making any modification
> between the two runs (i.e. the same Ruby on the same workload), the results
> are exactly the same. So I don't think there is any random effect to cause
> the above difference. Then, are the results I have got reasonable?
>
> Thanks,
> Lide
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Gems-users mailing list
> Gems-users@xxxxxxxxxxx
> https://lists.cs.wisc.edu/mailman/listinfo/gems-users
> Use Google to search the GEMS Users mailing list by adding "site:https://lists.cs.wisc.edu/archive/gems-users/ " to your search.
>
>

_______________________________________________
Gems-users mailing list
Gems-users@xxxxxxxxxxx
https://lists.cs.wisc.edu/mailman/listinfo/gems-users
Use Google to search the GEMS Users mailing list by adding "site:https://lists.cs.wisc.edu/archive/gems-users/ " to your search.