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

["Daniele Bordes" <daniele.bordes@xxxxxxxxx>]

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.

>     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.

>     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).
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.