Hi Ali,

  command line:
    /home/tracy/m5_2.0b/m5/build/ALPHA_FS/m5.opt
    -d /home/tracy/m5_2.0b/simulation/result/
    --stats-file=/home/tracy/m5_2.0b/simulation/result/ValStream_seq.sta
    /home/tracy/m5_2.0b/simulation/configs/seq/fs.py
    -b ValStream

  config file:
    cpu = TimingSimpleCPU()
    mem_mode = 'timing'
    cpu.clock = '2GHz'

    root = Root(clock = '1THz',
                system = makeLinuxAlphaSystem(mem_mode, bm[0]))
    root.system.cpu = cpu
    root.system.physmem = DetailedSdram(range = AddrRange(bm[0].mem()))
    root.system.physmem.port = root.system.membus.port
    cpu.connectMemPorts(root.system.membus)
    cpu.mem = root.system.physmem
    cpu.max_insts_all_threads = 1000000000

    DetailedSdram: I define my page placement policy in this python class.

  Here are stat files for different CPU model and page placement policies
(running 1 billion instructions):
(TimingSimpleCPU model, DRAM model in full system)
sim_ticks                               2345003956674
system.physmem.average_dram_latency         17.893534
system.physmem.row_conflict_rate             0.381053                     
 system.physmem.row_empty_rate                0.029279                    
  system.physmem.row_hit_rate                  0.589668
system.physmem.total_access                1255245361
system.physmem.total_row_conflict           478314873                     
 system.physmem.total_row_empty               36752550                    
  system.physmem.total_row_hit                740177934

(TimingSimpleCPU model, DRAM model with least_used_bank policy)
sim_ticks                               2345002809841
system.physmem.average_dram_latency         10.066127
system.physmem.row_conflict_rate             0.000148
system.physmem.row_empty_rate                0.000100
system.physmem.row_hit_rate                  0.999747
system.physmem.total_access                1255245862
system.physmem.total_row_conflict              186367
system.physmem.total_row_empty                 125238
system.physmem.total_row_hit               1254928724

(AtomicSimpleCPU, DRAM model in full system)
sim_ticks                               2216005337300
system.physmem.average_dram_latency         20.982500
system.physmem.row_conflict_rate             0.379750                     
 system.physmem.row_empty_rate                0.032733                    
  system.physmem.row_hit_rate                  0.587517
system.physmem.total_access                1256533655
system.physmem.total_row_conflict           477168551                     
 system.physmem.total_row_empty               41130200                    
  system.physmem.total_row_hit                738234896

(AtomicSimpleCPU, DRAM model with least_used_bank policy)
sim_ticks                               2216005337027
system.physmem.average_dram_latency         16.343905
system.physmem.row_conflict_rate             0.044255
system.physmem.row_empty_rate                0.368228
system.physmem.row_hit_rate                  0.587517
system.physmem.total_access                1256533655
system.physmem.total_row_conflict            55607405
system.physmem.total_row_empty              462690794
system.physmem.total_row_hit                738235394



    My question is :
    1) why I only change the CPU model, the difference of row hit rate is
so high? By using TimingSimpleCPU model, the row hit rate is more than
99%.
    2) In TimingSimpleCPU model,why DRAM model with my page placement
policy has more than 40% decrease of average DRAM access latency
compared to the DRAM model without these policy, but no difference in
the sim_ticks.
    It seems like even in the TimingSimpleCPU model, the average DRAM
latency is still not being accounted for.

Thanks,
Tracy



> Tracy,
>
> Why don't you give us your command line, important bits of your
> config files and the stats file to take a look at. Like the warning
> that is printed when you used the DRAM model says, it's largely
> untested, so something could be broken, but I don't think it's that
> broken.
>
> Ali
>
> On Jul 31, 2007, at 4:51 PM, [EMAIL PROTECTED] wrote:
>
>> Hi Ali,
>>
>>    I was using AtomicSimpleCPU to run simulation for 1 billion
>> instructions.
>> Now I change to use TimingSimpleCPU to run for 1 billion
>> instructions. The
>> difference of average DRAM access latency is even higher(more than
>> 40%),
>> but still 0% difference in sim_tick. Is that because 1 billion
>> instruction
>> is not enough to see any changes?
>>    I don't find any memory access queue in full system. How this
>> calculated DRAM latency is used?
>>    In the code, this latency will be transfered to sendTiming(pkt,
>> latency), and this function will call SimpleTimingPort::SendEvent
>> (this,
>> pkt, time);
>> Will the latency be used in the mainEventQueue?
>>
>> Thanks,
>> Tracy
>>
>>
>>
>>> There are two possibilities.
>>> a) You were running for a set number of ticks, so you wouldn't see
>>> any change in sim_ticks because the number of ticks was controlling
>>> the length of the simulation.
>>> b) You were using the AtomicSimpleCPU instead of either the
>>> TimingSimpleCPU or the O3CPU, so the DRAM latency wasn't being
>>> accounted for.
>>>
>>> Ali
>>>
>>> On Jul 27, 2007, at 9:44 PM, [EMAIL PROTECTED] wrote:
>>>
>>>> Hi,
>>>>
>>>>    I implement different page allocation algorithms(virtual to
>>>> physical
>>>> address translation algorithm) based on current DRAM model in full
>>>> system(m5_2.0b). After running simulations(benchmark is
>>>> ValStream), I
>>>> could see more than 20% difference in average DRAM access latency
>>>> within all these algorithms, but almost 0% difference in sim_ticks.
>>>>    Is that because the caculated dram latency is not used? Can
>>>> anybody
>>>> explain that to me?
>>>>    Thanks.
>>>>
>>>> Tracy
>>>> _______________________________________________
>>>> m5-users mailing list
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>>>> http://m5sim.org/cgi-bin/mailman/listinfo/m5-users
>>>>
>>>
>>> _______________________________________________
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>>
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>
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