diff options
| -rw-r--r-- | src/mem/SimpleDRAM.py | 6 | ||||
| -rw-r--r-- | src/mem/simple_dram.cc | 41 |
2 files changed, 32 insertions, 15 deletions
diff --git a/src/mem/SimpleDRAM.py b/src/mem/SimpleDRAM.py index a72bd518c..514ff3664 100644 --- a/src/mem/SimpleDRAM.py +++ b/src/mem/SimpleDRAM.py @@ -54,8 +54,10 @@ class MemSched(Enum): vals = ['fcfs', 'frfcfs'] # maximises parallelism. class AddrMap(Enum): vals = ['RoRaBaChCo', 'RoRaBaCoCh', 'RoCoRaBaCh'] -# Enum for the page policy, either open, open_adaptive or close. -class PageManage(Enum): vals = ['open', 'open_adaptive', 'close'] +# Enum for the page policy, either open, open_adaptive, close, or +# close_adaptive. +class PageManage(Enum): vals = ['open', 'open_adaptive', 'close', + 'close_adaptive'] # SimpleDRAM is a single-channel single-ported DRAM controller model # that aims to model the most important system-level performance diff --git a/src/mem/simple_dram.cc b/src/mem/simple_dram.cc index a8c3e0552..cb640dcb2 100644 --- a/src/mem/simple_dram.cc +++ b/src/mem/simple_dram.cc @@ -589,7 +589,8 @@ SimpleDRAM::printParams() const string address_mapping = addrMapping == Enums::RoRaBaChCo ? "RoRaBaChCo" : (addrMapping == Enums::RoRaBaCoCh ? "RoRaBaCoCh" : "RoCoRaBaCh"); string page_policy = pageMgmt == Enums::open ? "OPEN" : - (pageMgmt == Enums::open_adaptive ? "OPEN (adaptive)" : "CLOSE"); + (pageMgmt == Enums::open_adaptive ? "OPEN (adaptive)" : + (pageMgmt == Enums::close_adaptive ? "CLOSE (adaptive)" : "CLOSE")); DPRINTF(DRAM, "Memory controller %s characteristics\n" \ @@ -892,8 +893,9 @@ SimpleDRAM::estimateLatency(DRAMPacket* dram_pkt, Tick inTime) Tick potentialActTick; const Bank& bank = dram_pkt->bankRef; - // open-page policy - if (pageMgmt == Enums::open || pageMgmt == Enums::open_adaptive) { + // open-page policy or close_adaptive policy + if (pageMgmt == Enums::open || pageMgmt == Enums::open_adaptive || + pageMgmt == Enums::close_adaptive) { if (bank.openRow == dram_pkt->row) { // When we have a row-buffer hit, // we don't care about tRAS having expired or not, @@ -986,7 +988,8 @@ SimpleDRAM::recordActivate(Tick act_tick, uint8_t rank, uint8_t bank) // No need to update number of active banks for closed-page policy as only 1 // bank will be activated at any given point, which will be instatntly // precharged - if (pageMgmt == Enums::open || pageMgmt == Enums::open_adaptive) + if (pageMgmt == Enums::open || pageMgmt == Enums::open_adaptive || + pageMgmt == Enums::close_adaptive) ++numBanksActive; // start by enforcing tRRD @@ -1055,7 +1058,8 @@ SimpleDRAM::doDRAMAccess(DRAMPacket* dram_pkt) Bank& bank = dram_pkt->bankRef; // Update bank state - if (pageMgmt == Enums::open || pageMgmt == Enums::open_adaptive) { + if (pageMgmt == Enums::open || pageMgmt == Enums::open_adaptive || + pageMgmt == Enums::close_adaptive) { bank.freeAt = curTick() + addDelay + accessLat; // If you activated a new row do to this access, the next access @@ -1091,10 +1095,17 @@ SimpleDRAM::doDRAMAccess(DRAMPacket* dram_pkt) // if we did not hit the limit, we might still want to // auto-precharge - if (!auto_precharge && pageMgmt == Enums::open_adaptive) { - // a twist on the open page policy is to not blindly keep the + if (!auto_precharge && + (pageMgmt == Enums::open_adaptive || + pageMgmt == Enums::close_adaptive)) { + // a twist on the open and close page policies: + // 1) open_adaptive page policy does not blindly keep the // page open, but close it if there are no row hits, and there // are bank conflicts in the queue + // 2) close_adaptive page policy does not blindly close the + // page, but closes it only if there are no row hits in the queue. + // In this case, only force an auto precharge when there + // are no same page hits in the queue bool got_more_hits = false; bool got_bank_conflict = false; @@ -1106,9 +1117,10 @@ SimpleDRAM::doDRAMAccess(DRAMPacket* dram_pkt) // currently dealing with (which is the head of the queue) ++p; - // keep on looking until we have found both or reached - // the end - while (!(got_more_hits && got_bank_conflict) && + // keep on looking until we have found required condition or + // reached the end + while (!(got_more_hits && + (got_bank_conflict || pageMgmt == Enums::close_adaptive)) && p != queue.end()) { bool same_rank_bank = (dram_pkt->rank == (*p)->rank) && (dram_pkt->bank == (*p)->bank); @@ -1118,9 +1130,12 @@ SimpleDRAM::doDRAMAccess(DRAMPacket* dram_pkt) ++p; } - // auto pre-charge if we have not got any more hits, and - // have a bank conflict - auto_precharge = !got_more_hits && got_bank_conflict; + // auto pre-charge when either + // 1) open_adaptive policy, we have not got any more hits, and + // have a bank conflict + // 2) close_adaptive policy and we have not got any more hits + auto_precharge = !got_more_hits && + (got_bank_conflict || pageMgmt == Enums::close_adaptive); } // if this access should use auto-precharge, then we are |