Re: [Gems-users] Garnet Network parameters

[Niket Agarwal <niketa@xxxxxxxxxxxxx>]

You should check if the linkBuffer is empty or has a flit which will  
leave this cycle. You are checking the link_srcQueue!
If neither of the condition is true, which means that no flit is being  
picked up form the link_srcQueue, I think you would also need to  
reschedule the link the next cycle.
-Niket

On Oct 14, 2009, at 11:16 PM, Edward Lee wrote:

> Thanks for the tip. I followed the guidelines as suggested in the link
> and came up with the following. Anything I am missing?
>
> void NetworkLink_d::wakeup()
> {
>    if(link_srcQueue->isEmpty())
>    {
>        flit_d *t_flit = link_srcQueue->getTopFlit();
>        t_flit->set_time(g_eventQueue_ptr->getTime() + m_latency);
>        linkBuffer->insert(t_flit);
>        g_eventQueue_ptr->scheduleEvent(link_consumer, m_latency);
>        m_link_utilized++;
>        m_vc_load[t_flit->get_vc()]++;
>    }
>    else
>    {
>        flit_d *t_flit = link_srcQueue->getTopFlit();
>        if((t_flit->get_time()) <= (g_eventQueue_ptr->getTime()))
>        {
>            t_flit->set_time(g_eventQueue_ptr->getTime() + m_latency);
>            linkBuffer->insert(t_flit);
>            g_eventQueue_ptr->scheduleEvent(link_consumer, m_latency);
>            m_link_utilized++;
>            m_vc_load[t_flit->get_vc()]++;
>        }
>    }
> }
>
> -- Ed
>
> On Wed, Oct 14, 2009 at 7:52 PM, Niket Agarwal  
> <niketa@xxxxxxxxxxxxx> wrote:
> > You can model lower bandwidth links as you said. Please follow
> > https://lists.cs.wisc.edu/archive/gems-users/2009-April/ 
> > msg00076.shtml
> > -Niket
> >
> > Edward Lee wrote:
> > > Hi all,
> > >
> > > I would like to verify the meaning of some simulation parameters to
> > > come up with realistic network parameters.
> > > I am running a 2GHz serengeti machine with 16 processors using
> > > MOESI_SMP_directory protocol to simulate a 16-core CMP with private
> > > caches.
> > >
> > > Here are some configuration values:
> > >
> > > SIMICS_RUBY_MULTIPLIER: 4 --> does this mean Ruby clock is 2GHz/4  
> > > = 0.5GHz?
> > > network is 4x4 MESH via GARNET
> > > g_FLIT_SIZE: 16
> > >
> > > a snapshot of network parameters:
> > >
> > > ....
> > >
> > > ext_node:L1Cache:0 int_node:0 link_latency:1
> > > ext_node:Directory:0 int_node:0 link_latency:4
> > > int_node:0 int_node:1 link_latency:8 link_weight:1
> > >
> > > ...
> > >
> > > So, since FLIT_SIZE refers to bytes/cycle and it is suggested to  
> > > tune
> > > the latencies for lower bandwidths. Would it be accurate to make the
> > > following assumtions?
> > >
> > > 16 bytes/cycle * 0.5 Ghz / link_latency = link_bandwidth
> > >
> > > Accordingly,
> > >
> > > bandwidth to caches 8GB/s, bandwidth to memory/directory 2 GB/s,
> > > bandwidth between cores is 1GB/s
> > >
> > > Thanks for any input in advance,
> > >
> > > Ed
> > > _______________________________________________
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