Re: [Gems-users] Private L2 in a CMP...

[David Bonavila <david.bonavila@xxxxxxxxxxxxxxxxxx>]

Ruby says "Non-CMP protocol should set g_PROCS_PER_CHIP to 1" when using a SMP protocol and g_PROCS_PER_CHIP greater than 1, so I guess I will have to set g_PROCS_PER_CHIP to 1 and g_NUM_PROCESSORS to 2 to model a 2-core CMP.

There are 3 SMP protocols, and the first two of them use a unified L2 cache, so can I only use MOESI_SMP_hammer??

Which network latency parameters should I set to have a good approach of a CMP using 2 chips??

Thank you!!

2009/6/15 David Bonavila <david.bonavila@xxxxxxxxxxxxxxxxxx>

OK, thanks.
I need to model a 2-core CMP with private L2 for each of the cores.
Then, how should I configure these parameters?? I guess it should be something like this:

ruby0.setparam g_PROCS_PER_CHIP 1
ruby0.setparam g_NUM_PROCESSORS 2

Is that right?? Should I set any other parameters or configuration??
I have read something about making a fast interconnect between chips. Do I need any of that??

Thank you again!!

2009/6/15 David Bonavila <david.bonavila@xxxxxxxxxxxxxxxxxx>

Hi.

I need to configure a CMP with a private L2 cache, and I would like to know which of these configs I should use:

1)
ruby0.setparam g_PROCS_PER_CHIP 1
ruby0.setparam g_NUM_PROCESSORS 2

2)
ruby0.setparam g_PROCS_PER_CHIP 2
ruby0.setparam g_NUM_PROCESSORS 2
ruby0.setparam_str g_CACHE_DESIGN PRIVATE_L2

3)
ruby0.setparam g_PROCS_PER_CHIP 1
ruby0.setparam g_NUM_PROCESSORS 2
ruby0.setparam_str g_CACHE_DESIGN PRIVATE_L2

As I want to simulate a CMP, I guess I should use config number 2, but I don't know if that is the right way to do what I want.
Does config number 1 (without the g_CACHE_DESIGN parameter) provide a private L2 cache??
Or is any of them acceptable and the result will be the same??

Thanks!!