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

[Niket <niketa@xxxxxxxxxxxxx>]

Can you tell more about the changes that you made.

I think that the interconnect might generate different amount of 
messages due to routing.
Also, I am surprised that running Ruby twice gave you exactly the same 
result. It is surprising that the OS did not cause any randomizations.
-Niket

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
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