[Gems-users] problems when create a victimbuffer in L1.sm

["shanshuchang" <shanshuchang@xxxxxxxxx>]

Hi all,

I am now trying to add a victimBuffer between L1 and L2 cache based on MOESI_CMP_directory protocol. The victimBuffer was declared in L1.sm with template_hack="L1Cache_Entry".

 

Here are some pieces of problems I have encountered :

(1) about machineType.

I suppose that I should add new machinetype for VictimBuffer structure and also the mapping function from L1 cache to victimbuffer.

Think about the action a_issueGETS in original L1Cache.sm:

 

  action(a_issueGETS, "a", desc="Issue GETS") {
    peek(mandatoryQueue_in, CacheMsg) {
      enqueue(requestNetwork_out, RequestMsg, latency="L1_REQUEST_LATENCY") {
        out_msg.Address := address;
        out_msg.Type := CoherenceRequestType:GETS;
        out_msg.Requestor := machineID;
        out_msg.Destination.add(map_L1CacheMachId_to_L2Cache(address, machineID));
        out_msg.MessageSize := MessageSizeType:Request_Control;
        out_msg.AccessMode := in_msg.AccessMode;
        out_msg.Prefetch := in_msg.Prefetch;
      }
    }
  }

 

Now in case of a victim buffer,I would like the GETS request be sent to the victimQueue. For the "a_issueGETS" action, I think the out_msg.Destination must be modified to guarantee the request message be transferred to the right Victim Buffer.

 

It seems that I need to write the mapping function like this：

 

inline MachineID map_L1CacheMachId_to_L1VictimBuffer(address,machineID);

{
 int num = 0;
 MachineID mach = {MACHINETYPE_VICTIM_ENUM,0};
 mach.num = machineIDToNodeID(L1CacheMachId);
 return mach;

 

}

 

(2) about trigger event.
Two messagebuffer victimRequestQueue and victimResponseQueue were created here.

The former is used to transfer requests to the buffer, while the later is created to response the data message to L1 requestor.

 However,dislike the L2 cache, the victimBuffer need not do state transtions, thus one of the two messagebuffers should not trigger events within the in_port processing

On the other hand, I have checked that all the in_port processing contains the event triggering like this:

 

 

in_port(requestNetwork_in, RequestMsg, requestToL1Cache) {

  ...

  if(){trigger(Event:xxx),in_msg.address;

  ...

 

} 

 

I have already tried not to write in_port codes for victimResponeseQueue, but make error complains that:

 Error: Unrecognized variable: victimResponseQueue_in 

 

Have I did some misunderstanding of the processing scheme of the in_port/out_port? Any advice of how to do communication between L1 and victimbuffer?

 

Thanks...