Re: [Gems-users] Ruby_cycles != opal0.cycle ?!

["Min Xu (Hsu)" <xu@xxxxxxxxxxx>]

Weihang,

First question first, the multiplier is used to allow us to
use the in-order simics cpu model to approximate a N-way issue
super-scalar processor. In other words, every ruby cycle, we
could allow N-instructions to be executed in simics.

However, when running with opal, the multiplier should be set
to 1, because every opal cycle, up to X number of instructions
are executed. There is no need to allow opal advance N cycles
for every 1 ruby cycle, unless you want to simulate a slower
memory somehow.

As to your second question, when opal is running with ruby,
its own cache model is not used. So the parameters you listed
are safe to ignore. The only case where opal's own cache model
is used is when running single processor simulation without
ruby. Opal's own cache model doesn't support coherence yet.

-Min

On Thu, 03 Mar 2005 Weihang Jiang wrote :
> One related question:
> opal0.listparam lists configuration related to Memory System:
> 
> IL1_ASSOC                                   :                1
> IL1_SET_BITS                                :                8
> IL1_BLOCK_BITS                              :                6
> IL1_MSHR_ENTRIES                            :              256
> IL1_STREAM_BUFFERS                          :                0
> IL1_IDEAL                                   :                0
> IL1_NL_TYPE                                 :                0
> IL1_NL_LINES                                :                0
> IL1_MSHR_QUEUE_SIZE                         :               32
> IL1_MSHR_QUEUE_ISSUE_WIDTH                  :                2
> DL1_ASSOC                                   :                1
> DL1_SET_BITS                                :                8
> DL1_BLOCK_BITS                              :                6
> DL1_MSHR_ENTRIES                            :              256
> DL1_STREAM_BUFFERS                          :                0
> DL1_IDEAL                                   :                0
> L2_ASSOC                                    :                4
> L2_SET_BITS                                 :               12
> L2_BLOCK_BITS                               :                6
> L2_MSHR_ENTRIES                             :              128
> L2_STREAM_BUFFERS                           :                0
> L2_LATENCY                                  :                6
> L2_IDEAL                                    :                0
> MEMORY_DRAM_LATENCY                         :               80
> 
> Most of them can also be found in ruby. Do I need to unify these
> values between ruby and opal? Or it is only useful when opal is used
> alone?
> 
> 
> On Thu, 3 Mar 2005 21:58:28 -0600, Weihang Jiang
> <weihang.jiang@xxxxxxxxx> wrote:
> > Min:
> > Yes, it has been set to 2. What is the exact use of "multiplier"? When
> > should it be used?
> > 
> > Thanks
> > 
> > 
> > On Thu, 3 Mar 2005 21:06:19 -0600, Min Xu (Hsu) <xu@xxxxxxxxxxx> wrote:
> > > Weihang,
> > >
> > > I notice the opal cycle is exactly twice of the ruby cycle.
> > > I think the difference came from the ruby/opal multiplier.
> > > Did you set the multiplier to 2?
> > >
> > > -Min
> > >
> > > On Thu, 03 Mar 2005 Weihang Jiang wrote :
> > > > Hi,
> > > >     opal0.cycle tells me that "The current cycle is: 228737428". But
> > > > ruby0.dump-stats tells
> > > > me that "Ruby_cycles: 114368714". Why?
> > > >
> > > >
> > > >
> > > >
> > > > --
> > > > Weihang Jiang
> > > > _______________________________________________
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> > 
> > --
> > Weihang Jiang
> > 
> 
> 
> -- 
> Weihang Jiang