Re: [Gems-users] ruby parameter selection

[Olya Krachina <okrachin@xxxxxxxxxx>]

> > L1_RESPONSE_LATENCY - value: 1 - used in MOESI_CMP_directory?
> > L2_RESPONSE_LATENCY - value: 6 - used in MOESI_CMP_directory?
I am new to gems myself, but i know that for CMP protocols, response latency 
approximates tag latency.

> > L1_REQUEST_LATENCY - value: 1 - what is the difference between REQUEST and
> RESPONSE?
> > L2_REQUEST_LATENCY - value: 6 - what is the difference between REQUEST and
> RESPONSE?
request latency, not sure exactly, but if you look into gems/protocols .sm file 
which is the cache controller(s) (those are separate for L1 and L2 for CMP), 
the ACTIONS use these parameters to enqueue message buffers (i think from cache 
to network only) on TRANSITIONS. You should be able to figure out the 
difference from there.

Olya

> -----Original Message-----
> From: gems-users-bounces@xxxxxxxxxxx [mailto:gems-users-bounces@xxxxxxxxxxx]
> On Behalf Of Dan Gibson
> Sent: Friday, April 11, 2008 9:32 PM
> To: Gems Users
> Subject: Re: [Gems-users] ruby parameter selection
> 
> Most of the timing variables are protocol-dependent, unfortunately.
> Grep through MOESI_CMP_directory to discover which variables it uses, 
> and how. I'm no expert on that protocol, so I cannot answer your 
> question directly.
> 
> Regards,
> Dan
> 
> Mladen Nikitovic wrote:
> > Hi,
> >
> > I would like to model a pretty simple system with a L1 cache that has an 
> > access time of 1 cycle and an L2 access time of 6 cycles + latency of 
> > the network.
> >
> > I have a problem with setting up these parameters in ruby, especially 
> > the L1 latency.
> >
> > There are many parameters that seem related but it seems some are used 
> > in some protocols, not all.
> >
> > I'm using the MOESI_CMP_directory protocol.
> >
> > I managed to reduce the execution time of the application by changing 
> > the ruby_mutliplier from 2 to 1.
> >
> > The parameters that I'm hesitating about regarding cache latency are the 
> > following:
> >
> > DIRECTORY_CACHE_LATENCY - value: 6 - this latency is used when accessing 
> > the L2, right?
> > ISSUE_LATENCY - value: 2 - what type of issue is this? where is this 
> > issue performed?
> >
> > CACHE_RESPONSE_LATENCY - value: 12 -  Is this L1 or L2? Is it used in 
> > MOESI_CMP_directory protocol?
> > L1_RESPONSE_LATENCY - value: 1 - used in MOESI_CMP_directory?
> > L2_RESPONSE_LATENCY - value: 6 - used in MOESI_CMP_directory?
> >
> > RECYCLE_LATENCY - value: 3 - when is recycling performed?
> > L2_RECYCLE_LATENCY - value: 5 - when is recycling performed?
> >
> > L1_REQUEST_LATENCY - value: 1 - what is the difference between REQUEST 
> > and RESPONSE?
> > L2_REQUEST_LATENCY - value: 6 - what is the difference between REQUEST 
> > and RESPONSE?
> >
> > SEQUENCER_TO_CONTROLLER_LATENCY- value: 4 - should this be 1 or can I 
> > put it to 0?
> >
> > One general question is whether I need to assign 0 to any of these 
> > values to achieve my objective.
> >
> > Hope you have the time to sort out the meaning of these parameters.
> >
> > Regards,
> > Mladen
> >
> > _______________________________________________
> > 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.
> >
> >
> >   
> 
> -- 
> http://www.cs.wisc.edu/~gibson [esc]:wq!
> 
> _______________________________________________
> 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.
> 
> 
> _______________________________________________
> 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.
> 
>