bool SingleMSHR<Addr_t, Cache_t>::issue(Addr_t paddr, MemOperation mo)
{
MSHRit it = ms.find(calcLineAddr(paddr));
nUse.inc();
if(mo == MemRead)
nUseReads.inc();
if(mo == MemWrite)
nUseWrites.inc();
if(!overflow.empty()) {
return false;
}
I(nFreeEntries >= 0 && nFreeEntries <=nEntries);
if(it == ms.end()) {
if(nFreeEntries > 0) {
ms[calcLineAddr(paddr)].firstRequest(paddr, calcLineAddr(paddr),
nReads, nWrites, mo);
bf.insert(calcLineAddr(paddr));
nFreeEntries--;
#ifdef MSHR_BASICOCCSTATS
updateOccHistogram();
#endif
nOutsReqs++;
#ifdef MSHR_BASICOCCSTATS
if(mo == MemRead)
occStats->incRdReqs();
#endif
nIssuesNewEntry.inc();
avgQueueSize.sample(0);
checkSubEntries(paddr, mo);
#ifdef MSHR_EXTRAOCCSTATS
occStats->sampleEntry( calcLineAddr(paddr) );
#endif
return true;
}
}
return false;
}
bool SingleMSHR<Addr_t, Cache_t>::isOnlyWrites(Addr_t paddr)
{
const_MSHRit it = ms.find(calcLineAddr(paddr));
I(it != ms.end());
return ((*it).second.getUsedReads() == 0);
}
bool SingleMSHR<Addr_t, Cache_t>::canAcceptRequestSpecial(Addr_t paddr, MemOperation mo)
{
if(!overflow.empty()) {
nCanNotAccept.inc();
return false;
}
const_MSHRit it = ms.find(calcLineAddr(paddr));
I(nFreeEntries >= 0 && nFreeEntries <= nEntries);
if(it == ms.end()) {
if(nFreeEntries <= 0) {
nCanNotAccept.inc();
return false;
}
nCanAccept.inc();
return true;
}
I(it != ms.end());
bool canAccept = (*it).second.canAcceptRequest(mo);
if(canAccept)
nCanAccept.inc();
else {
nCanNotAccept.inc();
if(mo == MemWrite && !(*it).second.hasFreeWrites())
nCanNotAcceptTooManyWrites.inc();
else
nCanNotAcceptSubEntryFull.inc();
}
return canAccept;
}
MSHRentry<Addr_t>* SingleMSHR<Addr_t, Cache_t>::getEntry(Addr_t paddr)
{
MSHRentry<Addr_t> *me = NULL;
MSHRit dispIt = ms.find(calcLineAddr(paddr));
if(dispIt!=ms.end())
me = &((*dispIt).second);
return me;
}
void SingleMSHR<Addr_t, Cache_t>::checkSubEntries(Addr_t paddr, MemOperation mo)
{
MSHRit it = ms.find(calcLineAddr(paddr));
I(it != ms.end());
if((*it).second.isRdWrSharing()) {
if(!(*it).second.hasFreeReads() ||!(*it).second.hasFreeWrites()) {
nFullReadEntries++;
nFullWriteEntries++;
}
} else {
if(!(*it).second.hasFreeReads() && mo == MemRead) {
nFullReadEntries++;
}
if(!(*it).second.hasFreeWrites() && mo == MemWrite) {
nFullWriteEntries++;
}
}
}
void SingleMSHR<Addr_t, Cache_t>::addEntry(Addr_t paddr, CallbackBase *c,
CallbackBase *ovflwc, MemOperation mo)
{
MSHRit it = ms.find(calcLineAddr(paddr));
I(ovflwc); // for single MSHR, overflow handler REQUIRED!
if(!overflow.empty()) {
toOverflow(paddr, c, ovflwc, mo);
return;
}
if(it == ms.end()) {// we must be overflowing because the issue did not happen
toOverflow(paddr, c, ovflwc, mo);
return;
}
I(it != ms.end());
if((*it).second.addRequest(paddr, c, mo)) {
// ok, the addrequest succeeded, the request was added
avgQueueSize.sample((*it).second.getPendingReqs() - 1);
nOutsReqs++;
#ifdef MSHR_BASICOCCSTATS
if(mo == MemRead)
occStats->incRdReqs();
#endif
// there was no overflow, so the callback needs to be destroyed
ovflwc->destroy();
// check to see if we have filled up the subentries
checkSubEntries(paddr, mo);
//MSG("[%llu] nFullRd=%d nFullWr=%d a:%lu",globalClock,
// nFullReadEntries,nFullWriteEntries, calcLineAddr(paddr));
return;
} else {
// too many oustanding requests to the same line already. send to overflow
toOverflow(paddr, c, ovflwc, mo);
return;
}
}
bool SingleMSHR<Addr_t, Cache_t>::retire(Addr_t paddr)
{
bool rmEntry = false;
MSHRit it = ms.find(calcLineAddr(paddr));
I(it != ms.end());
I(calcLineAddr(paddr) == (*it).second.getLineAddr());
maxOutsReqs.sample(nOutsReqs);
nOutsReqs--;
//MSG("[%llu] nFullSubE=%d a=%lu",globalClock,nFullReadEntries,calcLineAddr(paddr));
rmEntry = (*it).second.retire();
if(rmEntry) {
// the last pending request for the MSHRentry was completed
// recycle the entry
nRetiredEntries.inc();
avgReqsPerLine.sample((*it).second.getUsedReads() + (*it).second.getUsedWrites());
maxUsedEntries.sample(nEntries - nFreeEntries);
avgWritesPerLine.sample((*it).second.getUsedWrites());
avgWritesPerLineComb.sample((*it).second.getNWrittenWords());
occStats->decRdReqs((*it).second.getUsedReads());
if((*it).second.getUsedWrites() > 0)
nRetiredEntriesWritten.inc();
if( ! (*it).second.hasFreeReads() ) {
nFullReadEntries--;
I(nFullReadEntries>=0);
}
if( ! (*it).second.hasFreeWrites() ) {
nFullWriteEntries--;
I(nFullWriteEntries>=0);
}
if((*it).second.isL2Hit())
occStats->avgReadSubentriesL2Hit.sample((*it).second.getUsedReads());
else
occStats->avgReadSubentriesL2Miss.sample((*it).second.getUsedReads());
#ifdef MSHR_EXTRAOCCSTATS
// extra MSHR occ stats
occStats->subEntriesHist.sample((*it).second.getUsedReads()+
(*it).second.getUsedWrites(), 1);
occStats->subEntriesReadsHist.sample((*it).second.getUsedReads(), 1);
occStats->subEntriesWritesHist.sample((*it).second.getUsedWrites(), 1);
occStats->subEntriesWritesHistComb.sample((*it).second.getNWrittenWords(), 1);
occStats->subEntriesHistComb.sample((*it).second.getUsedReads()+
(*it).second.getNWrittenWords(), 1);
if((*it).second.getUsedReads() == 0 &&
(*it).second.getUsedWrites() > 0) {
nOnlyWrites.inc();
occStats->retireWrEntry((*it).second.getLineAddr());
} else if( (*it).second.getUsedReads() > 0 &&
(*it).second.getUsedWrites() == 0 ) {
occStats->retireRdEntry((*it).second.getLineAddr());
} else {
I( (*it).second.getUsedWrites() > 0 );
I( (*it).second.getUsedReads() > 0 );
occStats->retireRdWrEntry((*it).second.getLineAddr());
}
#endif
nFreeEntries++;
updateOccHistogram();
bf.remove((*it).second.getLineAddr());
ms.erase(it);
}
checkOverflow();
return rmEntry;
}
void SingleMSHR<Addr_t, Cache_t>::checkOverflow()
{
if(overflow.empty()) //nothing to do
return;
if(checkingOverflow) // i am already checking the overflow
return;
I(!overflow.empty());
I(!checkingOverflow);
checkingOverflow = true;
int nConsumed = 0;
do {
OverflowField f = overflow.front();
MSHRit it = ms.find(calcLineAddr(f.paddr));
if(it == ms.end()) {
if(nFreeEntries > 0) {
ms[calcLineAddr(f.paddr)].firstRequest(f.paddr, calcLineAddr(f.paddr),
nReads, nWrites, f.mo);
checkSubEntries(f.paddr, f.mo);
#ifdef MSHR_EXTRAOCCSTATS
occStats->sampleEntry( calcLineAddr( f.paddr ) );
#endif
bf.insert(calcLineAddr(f.paddr));
nFreeEntries--;
updateOccHistogram();
nConsumed++;
nOutsReqs++;
if(f.mo == MemRead)
occStats->incRdReqs();
f.ovflwcb->call();
f.cb->destroy();
overflow.pop_front();
nIssuesNewEntry.inc();
avgQueueSize.sample(0);
} else {
break;
}
} else { // just try to add the entry
if((*it).second.addRequest(f.paddr, f.cb, f.mo)) {
// succesfully accepted entry, but no need to call the callback
// since there was already an entry pending for the same line
avgQueueSize.sample((*it).second.getPendingReqs() - 1);
f.ovflwcb->destroy();
overflow.pop_front();
nOutsReqs++;
if(f.mo == MemRead)
occStats->incRdReqs();
checkSubEntries(f.paddr, f.mo);
//MSG("[%llu] nFullRd=%d nFullWr=%d a:%lu",globalClock,
// nFullReadEntries,nFullWriteEntries,calcLineAddr(f.paddr));
} else {
break;
}
}
} while(!overflow.empty());
if(nConsumed)
avgOverflowConsumptions.sample(nConsumed);
checkingOverflow = false;
}
