Re: [Gems-users] about the network link bandwidth

[guo fei <gsta_guofei@xxxxxxxxxxxx>]

Thanks for your reply.

But when I look at the code, I have a question.

the link utilization is calculated as follow

double Throttle::getUtilization() const
{
  return (100.0 * double(m_links_utilized)) / (double(g_eventQueue_ptr->getTime()-m_ruby_start));
}

the m_links_utilized is accumulated for every message by following code:
      m_links_utilized += ratio;
where ratio is the percentage of occupied network bandwidth for 
transfering this message.

In the getUtilization() function, the dominator is the total number of
execution cycles, why the link usage is calculated like this?

I ask this question because in my simulation, the L2->Dir link utilization value
is 1.67 which is larger than 1. I dont understand what this mean?
The link is always busy or the link is overloaded? 

Thank you!

Fei




Mike Marty
 <mikem@xxxxxxxxxxx> 写道：
>  > I have some questions about the network bandwidth.
> > I notice that in ruby default configuration, there is a variable
> >
> > g_endpoint_bandwidth:10000
> > what does this value mean?
> >
>
> The bandwidth for each link is multiplied by this value.  The unit for
> bandwidth is "thousandths of a byte".  Thus if the link specifies a
> multiplier of "10" and the g_endpoint_bandwidth is 10000, then that link
> can deliver 100000 thousandths of a byte per cycle...or 100 bytes.
>
> > and when I dump the ruby stat file, in the network stats
> > section:  it shows the links_utilized_percent_swich_X_link_X:
> > the first value gets from "throttle_ptr->getUtilization()" function,
> > what does this value mean?
> >
>
> The utilization of the link
>
> All of the
>  networking code is in $GEMS/ruby/simple/network
>
>
> > Finally, in the slicc files (I am looking at
> > "MSI_MOESI_CMP" architecture), I did not find how the
> > NETWORK_LINK_LATENCY value is applied to the latency of
> > L2->dir requests when they are put into
> > "DirRequestIntraChipL2Network_out" queue,
> > where can I find the code that dealing with adding latencies
> > to requests according to the network topology.
> >
>
> NETWORK_LINK_LATENCY is used by some of the auto-generated networks in
> $GEMS/ruby/network/simple/Topology.C
>
> _______________________________________________
> 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.

---

Mp3疯狂搜-新歌热歌高速下