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ruby: add support for prefetching to MESI protocol

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This commit is contained in:
Nilay Vaish 2012-12-11 10:05:56 -06:00
parent c120273708
commit f3d0be210f
5 changed files with 380 additions and 11 deletions
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6
configs/ruby/MESI_CMP_directory.py
View file

@ -87,6 +87,8 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
start_index_bit = block_size_bits,
is_icache = False)
prefetcher = RubyPrefetcher.Prefetcher()
l1_cntrl = L1Cache_Controller(version = i,
cntrl_id = cntrl_count,
L1IcacheMemory = l1i_cache,
@ -94,7 +96,9 @@ def create_system(options, system, piobus, dma_ports, ruby_system):
l2_select_num_bits = l2_bits,
send_evictions = (
options.cpu_type == "detailed"),
ruby_system = ruby_system)
prefetcher = prefetcher,
ruby_system = ruby_system,
enable_prefetch = False)
cpu_seq = RubySequencer(version = i,
icache = l1i_cache,

363
src/mem/protocol/MESI_CMP_directory-L1cache.sm
View file

@ -31,11 +31,13 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
: Sequencer * sequencer,
CacheMemory * L1IcacheMemory,
CacheMemory * L1DcacheMemory,
Prefetcher * prefetcher = 'NULL',
int l2_select_num_bits,
int l1_request_latency = 2,
int l1_response_latency = 2,
int to_l2_latency = 1,
bool send_evictions
bool send_evictions,
bool enable_prefetch = "False"
{
// NODE L1 CACHE
// From this node's L1 cache TO the network
@ -51,6 +53,9 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
MessageBuffer requestToL1Cache, network="From", virtual_network="0", ordered="false", vnet_type="request";
// a L2 bank -> this L1
MessageBuffer responseToL1Cache, network="From", virtual_network="1", ordered="false", vnet_type="response";
// Request Buffer for prefetches
MessageBuffer optionalQueue, ordered="false";
// STATES
state_declaration(State, desc="Cache states", default="L1Cache_State_I") {
@ -70,6 +75,11 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
M_I, AccessPermission:Busy, desc="L1 replacing, waiting for ACK";
SINK_WB_ACK, AccessPermission:Busy, desc="This is to sink WB_Acks from L2";
// Transient States in which block is being prefetched
PF_IS, AccessPermission:Busy, desc="Issued GETS, have not seen response yet";
PF_IM, AccessPermission:Busy, desc="Issued GETX, have not seen response yet";
PF_SM, AccessPermission:Busy, desc="Issued GETX, received data, waiting for acks";
PF_IS_I, AccessPermission:Busy, desc="Issued GETs, saw inv before data";
}
// EVENTS
@ -98,6 +108,10 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
Ack_all, desc="Last ack for processor";
WB_Ack, desc="Ack for replacement";
PF_Load, desc="load request from prefetcher";
PF_Ifetch, desc="instruction fetch request from prefetcher";
PF_Store, desc="exclusive load request from prefetcher";
}
// TYPES
@ -107,6 +121,7 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
State CacheState, desc="cache state";
DataBlock DataBlk, desc="data for the block";
bool Dirty, default="false", desc="data is dirty";
bool isPrefetch, desc="Set if this block was prefetched";
}
// TBE fields
@ -227,6 +242,19 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
}
}
Event prefetch_request_type_to_event(RubyRequestType type) {
if (type == RubyRequestType:LD) {
return Event:PF_Load;
} else if (type == RubyRequestType:IFETCH) {
return Event:PF_Ifetch;
} else if ((type == RubyRequestType:ST) ||
(type == RubyRequestType:ATOMIC)) {
return Event:PF_Store;
} else {
error("Invalid RubyRequestType");
}
}
int getPendingAcks(TBE tbe) {
return tbe.pendingAcks;
}
@ -234,6 +262,89 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
out_port(requestIntraChipL1Network_out, RequestMsg, requestFromL1Cache);
out_port(responseIntraChipL1Network_out, ResponseMsg, responseFromL1Cache);
out_port(unblockNetwork_out, ResponseMsg, unblockFromL1Cache);
out_port(optionalQueue_out, RubyRequest, optionalQueue);
// Prefetch queue between the controller and the prefetcher
// As per Spracklen et al. (HPCA 2005), the prefetch queue should be
// implemented as a LIFO structure. The structure would allow for fast
// searches of all entries in the queue, not just the head msg. All
// msgs in the structure can be invalidated if a demand miss matches.
in_port(optionalQueue_in, RubyRequest, optionalQueue, desc="...", rank = 3) {
if (optionalQueue_in.isReady()) {
peek(optionalQueue_in, RubyRequest) {
// Instruction Prefetch
if (in_msg.Type == RubyRequestType:IFETCH) {
Entry L1Icache_entry := getL1ICacheEntry(in_msg.LineAddress);
if (is_valid(L1Icache_entry)) {
// The block to be prefetched is already present in the
// cache. We should drop this request.
trigger(prefetch_request_type_to_event(in_msg.Type),
in_msg.LineAddress,
L1Icache_entry, L1_TBEs[in_msg.LineAddress]);
}
// Check to see if it is in the OTHER L1
Entry L1Dcache_entry := getL1DCacheEntry(in_msg.LineAddress);
if (is_valid(L1Dcache_entry)) {
// The block is in the wrong L1 cache. We should drop
// this request.
trigger(prefetch_request_type_to_event(in_msg.Type),
in_msg.LineAddress,
L1Dcache_entry, L1_TBEs[in_msg.LineAddress]);
}
if (L1IcacheMemory.cacheAvail(in_msg.LineAddress)) {
// L1 does't have the line, but we have space for it
// in the L1 so let's see if the L2 has it
trigger(prefetch_request_type_to_event(in_msg.Type),
in_msg.LineAddress,
L1Icache_entry, L1_TBEs[in_msg.LineAddress]);
} else {
// No room in the L1, so we need to make room in the L1
trigger(Event:L1_Replacement,
L1IcacheMemory.cacheProbe(in_msg.LineAddress),
getL1ICacheEntry(L1IcacheMemory.cacheProbe(in_msg.LineAddress)),
L1_TBEs[L1IcacheMemory.cacheProbe(in_msg.LineAddress)]);
}
} else {
// Data prefetch
Entry L1Dcache_entry := getL1DCacheEntry(in_msg.LineAddress);
if (is_valid(L1Dcache_entry)) {
// The block to be prefetched is already present in the
// cache. We should drop this request.
trigger(prefetch_request_type_to_event(in_msg.Type),
in_msg.LineAddress,
L1Dcache_entry, L1_TBEs[in_msg.LineAddress]);
}
// Check to see if it is in the OTHER L1
Entry L1Icache_entry := getL1ICacheEntry(in_msg.LineAddress);
if (is_valid(L1Icache_entry)) {
// The block is in the wrong L1. Just drop the prefetch
// request.
trigger(prefetch_request_type_to_event(in_msg.Type),
in_msg.LineAddress,
L1Icache_entry, L1_TBEs[in_msg.LineAddress]);
}
if (L1DcacheMemory.cacheAvail(in_msg.LineAddress)) {
// L1 does't have the line, but we have space for it in
// the L1 let's see if the L2 has it
trigger(prefetch_request_type_to_event(in_msg.Type),
in_msg.LineAddress,
L1Dcache_entry, L1_TBEs[in_msg.LineAddress]);
} else {
// No room in the L1, so we need to make room in the L1
trigger(Event:L1_Replacement,
L1DcacheMemory.cacheProbe(in_msg.LineAddress),
getL1DCacheEntry(L1DcacheMemory.cacheProbe(in_msg.LineAddress)),
L1_TBEs[L1DcacheMemory.cacheProbe(in_msg.LineAddress)]);
}
}
}
}
}
// Response IntraChip L1 Network - response msg to this L1 cache
in_port(responseIntraChipL1Network_in, ResponseMsg, responseToL1Cache, rank = 2) {
@ -248,7 +359,9 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
trigger(Event:Data_Exclusive, in_msg.Address, cache_entry, tbe);
} else if(in_msg.Type == CoherenceResponseType:DATA) {
if ((getState(tbe, cache_entry, in_msg.Address) == State:IS ||
getState(tbe, cache_entry, in_msg.Address) == State:IS_I) &&
getState(tbe, cache_entry, in_msg.Address) == State:IS_I ||
getState(tbe, cache_entry, in_msg.Address) == State:PF_IS ||
getState(tbe, cache_entry, in_msg.Address) == State:PF_IS_I) &&
machineIDToMachineType(in_msg.Sender) == MachineType:L1Cache) {
trigger(Event:DataS_fromL1, in_msg.Address, cache_entry, tbe);
@ -368,6 +481,14 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
}
}
void enqueuePrefetch(Address address, RubyRequestType type) {
enqueue(optionalQueue_out, RubyRequest, latency=1) {
out_msg.LineAddress := address;
out_msg.Type := type;
out_msg.AccessMode := RubyAccessMode:Supervisor;
}
}
// ACTIONS
action(a_issueGETS, "a", desc="Issue GETS") {
peek(mandatoryQueue_in, RubyRequest) {
@ -386,6 +507,24 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
}
}
action(pa_issuePfGETS, "pa", desc="Issue prefetch GETS") {
peek(optionalQueue_in, RubyRequest) {
enqueue(requestIntraChipL1Network_out, RequestMsg,
latency=l1_request_latency) {
out_msg.Address := address;
out_msg.Type := CoherenceRequestType:GETS;
out_msg.Requestor := machineID;
out_msg.Destination.add(mapAddressToRange(address, MachineType:L2Cache,
l2_select_low_bit, l2_select_num_bits));
DPRINTF(RubySlicc, "address: %s, destination: %s\n",
address, out_msg.Destination);
out_msg.MessageSize := MessageSizeType:Control;
out_msg.Prefetch := in_msg.Prefetch;
out_msg.AccessMode := in_msg.AccessMode;
}
}
}
action(ai_issueGETINSTR, "ai", desc="Issue GETINSTR") {
peek(mandatoryQueue_in, RubyRequest) {
enqueue(requestIntraChipL1Network_out, RequestMsg, latency=l1_request_latency) {
@ -403,6 +542,26 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
}
}
action(pai_issuePfGETINSTR, "pai",
desc="Issue GETINSTR for prefetch request") {
peek(optionalQueue_in, RubyRequest) {
enqueue(requestIntraChipL1Network_out, RequestMsg,
latency=l1_request_latency) {
out_msg.Address := address;
out_msg.Type := CoherenceRequestType:GET_INSTR;
out_msg.Requestor := machineID;
out_msg.Destination.add(
mapAddressToRange(address, MachineType:L2Cache,
l2_select_low_bit, l2_select_num_bits));
out_msg.MessageSize := MessageSizeType:Control;
out_msg.Prefetch := in_msg.Prefetch;
out_msg.AccessMode := in_msg.AccessMode;
DPRINTF(RubySlicc, "address: %s, destination: %s\n",
address, out_msg.Destination);
}
}
}
action(b_issueGETX, "b", desc="Issue GETX") {
peek(mandatoryQueue_in, RubyRequest) {
@ -422,6 +581,29 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
}
}
action(pb_issuePfGETX, "pb", desc="Issue prefetch GETX") {
peek(optionalQueue_in, RubyRequest) {
enqueue(requestIntraChipL1Network_out, RequestMsg,
latency=l1_request_latency) {
out_msg.Address := address;
out_msg.Type := CoherenceRequestType:GETX;
out_msg.Requestor := machineID;
DPRINTF(RubySlicc, "%s\n", machineID);
out_msg.Destination.add(mapAddressToRange(address,
MachineType:L2Cache,
l2_select_low_bit,
l2_select_num_bits));
DPRINTF(RubySlicc, "address: %s, destination: %s\n",
address, out_msg.Destination);
out_msg.MessageSize := MessageSizeType:Control;
out_msg.Prefetch := in_msg.Prefetch;
out_msg.AccessMode := in_msg.AccessMode;
}
}
}
action(c_issueUPGRADE, "c", desc="Issue GETX") {
peek(mandatoryQueue_in, RubyRequest) {
enqueue(requestIntraChipL1Network_out, RequestMsg, latency= l1_request_latency) {
@ -584,7 +766,6 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
l2_select_low_bit, l2_select_num_bits));
out_msg.MessageSize := MessageSizeType:Response_Control;
DPRINTF(RubySlicc, "%s\n", address);
}
}
@ -700,6 +881,31 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
}
}
action(po_observeMiss, "\po", desc="Inform the prefetcher about the miss") {
peek(mandatoryQueue_in, RubyRequest) {
if (enable_prefetch) {
prefetcher.observeMiss(in_msg.LineAddress, in_msg.Type);
}
}
}
action(ppm_observePfMiss, "\ppm",
desc="Inform the prefetcher about the partial miss") {
peek(mandatoryQueue_in, RubyRequest) {
prefetcher.observePfMiss(in_msg.LineAddress);
}
}
action(pq_popPrefetchQueue, "\pq", desc="Pop the prefetch request queue") {
optionalQueue_in.dequeue();
}
action(mp_markPrefetched, "mp", desc="Write data from response queue to cache") {
assert(is_valid(cache_entry));
cache_entry.isPrefetch := true;
}
//*****************************************************
// TRANSITIONS
//*****************************************************
@ -709,16 +915,49 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
z_stallAndWaitMandatoryQueue;
}
transition({PF_IS, PF_IS_I}, {Store, L1_Replacement}) {
z_stallAndWaitMandatoryQueue;
}
transition({PF_IM, PF_SM}, {Load, Ifetch, L1_Replacement}) {
z_stallAndWaitMandatoryQueue;
}
// Transitions from Idle
transition({NP,I}, L1_Replacement) {
ff_deallocateL1CacheBlock;
}
transition({S,E,M,IS,IM,SM,IS_I,M_I,SINK_WB_ACK,PF_IS,PF_IM},
{PF_Load, PF_Store}) {
pq_popPrefetchQueue;
}
transition({NP,I}, Load, IS) {
oo_allocateL1DCacheBlock;
i_allocateTBE;
a_issueGETS;
uu_profileDataMiss;
po_observeMiss;
k_popMandatoryQueue;
}
transition({NP,I}, PF_Load, PF_IS) {
oo_allocateL1DCacheBlock;
i_allocateTBE;
pa_issuePfGETS;
pq_popPrefetchQueue;
}
transition(PF_IS, Load, IS) {
uu_profileDataMiss;
ppm_observePfMiss;
k_popMandatoryQueue;
}
transition(PF_IS_I, Load, IS_I) {
uu_profileDataMiss;
ppm_observePfMiss;
k_popMandatoryQueue;
}
@ -727,6 +966,22 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
i_allocateTBE;
ai_issueGETINSTR;
uu_profileInstMiss;
po_observeMiss;
k_popMandatoryQueue;
}
transition({NP,I}, PF_Ifetch, PF_IS) {
pp_allocateL1ICacheBlock;
i_allocateTBE;
pai_issuePfGETINSTR;
pq_popPrefetchQueue;
}
// We proactively assume that the prefetch is in to
// the instruction cache
transition(PF_IS, Ifetch, IS) {
uu_profileDataMiss;
ppm_observePfMiss;
k_popMandatoryQueue;
}
@ -735,6 +990,26 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
i_allocateTBE;
b_issueGETX;
uu_profileDataMiss;
po_observeMiss;
k_popMandatoryQueue;
}
transition({NP,I}, PF_Store, PF_IM) {
oo_allocateL1DCacheBlock;
i_allocateTBE;
pb_issuePfGETX;
pq_popPrefetchQueue;
}
transition(PF_IM, Store, IM) {
uu_profileDataMiss;
ppm_observePfMiss;
k_popMandatoryQueue;
}
transition(PF_SM, Store, SM) {
uu_profileDataMiss;
ppm_observePfMiss;
k_popMandatoryQueue;
}
@ -870,6 +1145,11 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
l_popRequestQueue;
}
transition({PF_IS, PF_IS_I}, Inv, PF_IS_I) {
fi_sendInvAck;
l_popRequestQueue;
}
transition(IS, Data_all_Acks, S) {
u_writeDataToL1Cache;
h_load_hit;
@ -878,6 +1158,14 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
transition(PF_IS, Data_all_Acks, S) {
u_writeDataToL1Cache;
s_deallocateTBE;
mp_markPrefetched;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
transition(IS_I, Data_all_Acks, I) {
u_writeDataToL1Cache;
h_load_hit;
@ -886,6 +1174,12 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
transition(PF_IS_I, Data_all_Acks, I) {
s_deallocateTBE;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
transition(IS, DataS_fromL1, S) {
u_writeDataToL1Cache;
j_sendUnblock;
@ -895,6 +1189,14 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
transition(PF_IS, DataS_fromL1, S) {
u_writeDataToL1Cache;
j_sendUnblock;
s_deallocateTBE;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
transition(IS_I, DataS_fromL1, I) {
u_writeDataToL1Cache;
j_sendUnblock;
@ -904,6 +1206,13 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
transition(PF_IS_I, DataS_fromL1, I) {
j_sendUnblock;
s_deallocateTBE;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
// directory is blocked when sending exclusive data
transition(IS_I, Data_Exclusive, E) {
u_writeDataToL1Cache;
@ -914,6 +1223,15 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
// directory is blocked when sending exclusive data
transition(PF_IS_I, Data_Exclusive, E) {
u_writeDataToL1Cache;
jj_sendExclusiveUnblock;
s_deallocateTBE;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
transition(IS, Data_Exclusive, E) {
u_writeDataToL1Cache;
h_load_hit;
@ -923,18 +1241,38 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
transition(PF_IS, Data_Exclusive, E) {
u_writeDataToL1Cache;
jj_sendExclusiveUnblock;
s_deallocateTBE;
mp_markPrefetched;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
// Transitions from IM
transition({IM, SM}, Inv, IM) {
fi_sendInvAck;
l_popRequestQueue;
}
transition({PF_IM, PF_SM}, Inv, PF_IM) {
fi_sendInvAck;
l_popRequestQueue;
}
transition(IM, Data, SM) {
u_writeDataToL1Cache;
q_updateAckCount;
o_popIncomingResponseQueue;
}
transition(PF_IM, Data, PF_SM) {
u_writeDataToL1Cache;
q_updateAckCount;
o_popIncomingResponseQueue;
}
transition(IM, Data_all_Acks, M) {
u_writeDataToL1Cache;
hh_store_hit;
@ -944,8 +1282,17 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
transition(PF_IM, Data_all_Acks, M) {
u_writeDataToL1Cache;
jj_sendExclusiveUnblock;
s_deallocateTBE;
mp_markPrefetched;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
// transitions from SM
transition({SM, IM}, Ack) {
transition({SM, IM, PF_SM, PF_IM}, Ack) {
q_updateAckCount;
o_popIncomingResponseQueue;
}
@ -958,6 +1305,14 @@ machine(L1Cache, "MESI Directory L1 Cache CMP")
kd_wakeUpDependents;
}
transition(PF_SM, Ack_all, M) {
jj_sendExclusiveUnblock;
s_deallocateTBE;
mp_markPrefetched;
o_popIncomingResponseQueue;
kd_wakeUpDependents;
}
transition(SINK_WB_ACK, Inv){
fi_sendInvAck;
l_popRequestQueue;

7
src/mem/protocol/RubySlicc_Types.sm
View file

@ -1,4 +1,3 @@
/*
* Copyright (c) 1999-2005 Mark D. Hill and David A. Wood
* All rights reserved.
@ -188,3 +187,9 @@ structure (GenericBloomFilter, external = "yes") {
bool isSet(Address, int);
int getCount(Address, int);
}
structure (Prefetcher, external = "yes") {
void observeMiss(Address, RubyRequestType);
void observePfHit(Address);
void observePfMiss(Address);
}

3
src/mem/slicc/ast/ObjDeclAST.py
View file

@ -41,9 +41,6 @@ class ObjDeclAST(DeclAST):
def generate(self):
machineComponentSym = False
if "hack" in self:
warning("'hack=' is now deprecated")
if "network" in self and "virtual_network" not in self:
self.error("Network queues require a 'virtual_network' attribute")

12
src/mem/slicc/symbols/StateMachine.py
View file

@ -41,7 +41,8 @@ python_class_map = {"int": "Int",
"Sequencer": "RubySequencer",
"DirectoryMemory": "RubyDirectoryMemory",
"MemoryControl": "MemoryControl",
"DMASequencer": "DMASequencer"
"DMASequencer": "DMASequencer",
"Prefetcher":"Prefetcher"
}
class StateMachine(Symbol):
@ -49,6 +50,7 @@ class StateMachine(Symbol):
super(StateMachine, self).__init__(symtab, ident, location, pairs)
self.table = None
self.config_parameters = config_parameters
self.prefetchers = []
for param in config_parameters:
if param.pointer:
@ -58,6 +60,8 @@ class StateMachine(Symbol):
var = Var(symtab, param.name, location, param.type_ast.type,
"m_%s" % param.name, {}, self)
self.symtab.registerSym(param.name, var)
if str(param.type_ast.type) == "Prefetcher":
self.prefetchers.append(var)
self.states = orderdict()
self.events = orderdict()
@ -69,9 +73,9 @@ class StateMachine(Symbol):
self.objects = []
self.TBEType = None
self.EntryType = None
self.message_buffer_names = []
def __repr__(self):
return "[StateMachine: %s]" % self.ident
@ -629,6 +633,10 @@ $vid->setDescription("[Version " + to_string(m_version) + ", ${ident}, name=${{v
else:
code('$vid->setRecycleLatency(m_recycle_latency);')
# Set the prefetchers
code()
for prefetcher in self.prefetchers:
code('${{prefetcher.code}}.setController(this);')
# Set the queue consumers
code()