Re: [Gems-users] How is ruby configured?

[Dan Gibson <degibson@xxxxxxxx>]

Bravo Daniele! Its great to see Gems users answering gems-users questions =).
Let me make a couple additional comments to each of your questions, Derin.

Daniele Bordes wrote:

2006/7/25, mehmetderin.harmanci@xxxxxxx <mehmetderin.harmanci@xxxxxxx>:
  

 Hello,

   I'm a new GEMS user. I have a few question about the usage of ruby.

   1) Is the memory hierarchy configurable in ruby (e.g. can we design a
      system with private I & D L1 caches followed by a shared L2 cache
      (shared between L1 caches of all processors), similarlarly can we
      configure a system with private L1 and L2 caches for each processors?)
      If we can configure the systems how is it done? in rubyconfig.defaults?

    

You can configure memory parameters editing rubyconfig.defaults only
BEFORE compiling ruby;
if you use simics, you can change the parameters at run-time by using
simics commands like this ones:

ruby0.setparam L1_CACHE_ASSOC 12
ruby0.setparam g_NUM_PROCESSORS 4

and so on...

If you use the tester.exec, you can change only some parameters by
using some command line options: for instance:

tester.exec -p 8

which set g_NUM_PROCESSORS = 8

Take a look inside /GEMS/ruby/tester/test_framework.C:  you will find
all command line options you can use to change parameters; obviously,
you can add command line flags in test_framework.C and recompile ruby
and the tester.
  

Most of the latency, bandwidth, cache size, etc. numbers are controlled by rubyconfig.defaults and/or subsequent run-time specification of parameters via ruby.setparam [paramname] [paramval].
However, the exact topology is determined by the "network" parameter. This can be one of the "built in networks", PT_TO_PT is an example, OR the network can be "FILE_SPECIFIED", in which case the network is built at runtime by reading a network input file. These reside in $GEMS/ruby/network/simple/Network_Files, and can be used as templates to build your own topologies. Unfortunately, I'm not aware of a great reference on the network files, other than simply staring at them until they make sense. BUT, you should DEFINATELY check out the WIKI page that Daniele recommended,

http://www.cs.wisc.edu/gems/doc/wiki/moin.cgi/How_do_I_understand_a_Protocol

    2) I compiled and finally managed to run ruby. However I'm not sure it
       works properly. Is there a way to test if it functions properly?
       (I compiled the protocol which is pointed in the Documentation -
        Quickstart page) Does the tester do this?

    

At first, I think you should read this:

http://www.cs.wisc.edu/gems/doc/wiki/moin.cgi/How_do_I_understand_a_Protocol

Tester.exec allows you to perform trace-driven simulations; the url
I've given shows you only two kind of memory operations:  data load
(LD) and data store (ST); to find other kind of possible operations, I
think you should find a file containing the definition of
"string_to_CacheRequestType" function; this function is called in
TraceRecord::input, and is used to "interpret" the operations (which
could be LD, ST and many others...) you specify in the trace file.
  

The best way to test ruby would be to load a checkpoint within Simics, run for a few cycles (say, 100000 or so), and have a look at ruby's output, as it shows in the QuickStart portion of the WIKI. Naturally, you'll need a checkpoint first, which is quite a chore in itself.

The second best way is to use the tester. After Ruby is built, the tester can be found in $GEMS/ruby/[platform]/bin/tester.exec ... its various functions are printed to the command line when invoked with no arguments.

    3) For measuring average memory request latency do we need to add some
       extra code or is this already given in the statistics created by
       ruby0.dump-stats (I looked into the file but there are many
       statistics that I'm not sure of).

    

No additional code is needed here. All miss latencies are profiled into a histogram by ruby automatically. Just open up a Ruby .stats file and search for miss_latency... you should see something like:
 miss_latency: [binsize: 16 max: 2265 count: 1296724 average: 60.9435 .... (etc)

The various latencies are also broken down by access type and cache.

Well, I think you don't need to add extra code, but I'm not sure; try
to look inside output files and search for "latency".

I hope this information are useful for you; well, this is all I know,
surely Gems's Authors will be more and more accurate.
  

Regards,
Dan

_______________________________________________
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.