Why not, just put a bus in between CPUs and L1? But why would you do so? Jack Harvard
On Fri, Nov 23, 2012 at 4:06 PM, Pavlos Maniotis <[email protected]>wrote: > Thanks Andreas, > > I would like to ask you one more thing: > Do you believe it is feasible to simulate > a system with L1 shared cache among cpus (either with ruby or with > Classic Memory System)? I have searched the mailing list but > I couldn't find some helpful info. > > On Fri, 2012-11-23 at 14:38 +0000, Andreas Hansson wrote: > > Hi Pavlos, > > > > There have been numerous discussions around the CPU to L1 > > bandwidth/latency, and by default it is not limited (i.e. it is just two > > ports connected together). IF you want (and as Steve has previously > > pointed out) you can insert a CoherentBus between the CPU and L1 if you > > want, but you will have to change the config scripts. > > > > Good luck. > > > > Andreas > > > > On 23/11/2012 14:34, "Pavlos Maniotis" <[email protected]> wrote: > > > > >Hi Andreas, > > > > > >Thanks for the info, does it also apply for the Classic Memory System? > > >I was thinking that there was a bus between CPU and L1 with some width > > >and some frequency, for example 64bit and 2GHz. I wanted to test two > > >different systems and compare the performance between them: > > > > > >1) CPU (2GHz) <--------[bus 64 width, 2GHz]---------> L1 (2GHz) ->to L2 > > >2) CPU (2GHz) <--------[bus 32 width, 4GHz]---------> L1 (4GHz) ->to L2 > > > > > >Do you think that I cannot use gem5 to do this experiment? > > > > > >Thanks again, > > >Pavlos > > >On Fri, 2012-11-23 at 14:14 +0000, Andreas Hansson wrote: > > >> Hi Pavlos, > > >> > > >> There is no bus between the CPU core and the L1, just a "port" > > >>connection. > > >> The PIO bus is only used for PIO, and should not have a great impact > on > > >> your benchmark unless it is very I/O intensive. > > >> > > >> Andreas > > >> > > >> On 23/11/2012 12:29, "Pavlos Maniotis" <[email protected]> wrote: > > >> > > >> >Hello everyone, > > >> > > > >> >I use ruby (MOESI_CMP_directory) and I want to simulate a system > > >> >with one CPU (frequency=2GHz) and L1 and L2 caches (frequency=4GHz). > > >> >I also want the bus between cpu and cache > > >> >to run at 4GHz with width 32 bits. So I have to set the cpu > > >> >frequency equal to 4GHz (ruby_fs.py -> CPUClass.clock = '2GHz') > > >> >and ruby frequency equal to 2GHz > > >> >(Ruby.py -> system.ruby = RubySystem(clock = 4, > > >> > stats_filename = options.ruby_stats, > > >> > no_mem_vec = options.use_map)). > > >> > > > >> >I suppose these changes are right, my main concern is: > > >> > > > >> >Do I have to change system.piobus frequency > > >> >to 4GHz and width to 4 bytes (file FSConfig.py, function > > >> >makeLinuxAlphaRubySystem)? > > >> >Is this the bus between cpu and L1 cache? If it is not > > >> >how can I configure the bus between L1 and CPU? > > >> > > > >> >I am little bit confused about the interconnection system. > > >> > > > >> >Thanks in advance for any help, > > >> >Pavlos > > >> > > > >> > > > >> >_______________________________________________ > > >> >gem5-users mailing list > > >> >[email protected] > > >> >http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > > >> > > > >> > > >> > > >> -- IMPORTANT NOTICE: The contents of this email and any attachments > are > > >>confidential and may also be privileged. If you are not the intended > > >>recipient, please notify the sender immediately and do not disclose the > > >>contents to any other person, use it for any purpose, or store or copy > > >>the information in any medium. Thank you. > > >> > > >> _______________________________________________ > > >> gem5-users mailing list > > >> [email protected] > > >> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > > > > > > > > >_______________________________________________ > > >gem5-users mailing list > > >[email protected] > > >http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > > > > > > > > > -- IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended > recipient, please notify the sender immediately and do not disclose the > contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. > > > > _______________________________________________ > > gem5-users mailing list > > [email protected] > > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > > > _______________________________________________ > gem5-users mailing list > [email protected] > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >
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