sanchayanmaity/gem5
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

mem: Separate out the different cases for DRAM bus busy time

Browse source 
This patch changes how the data bus busy time is calculated such that
it is delayed to the actual scheduling time of the request as opposed
to being done as soon as possible.

This patch changes a bunch of statistics, and the stats update is
bundled together with the introruction of tFAW/tTAW and the named DRAM
configurations like DDR3 and LPDDR2.
This commit is contained in:
Andreas Hansson 2013-01-31 07:49:13 -05:00
parent af0f8b31db
commit b7153e2a64
1 changed files with 8 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
src/mem/simple_dram.cc
View file

@ -299,13 +299,16 @@ SimpleDRAM::processWriteEvent()
if (pageMgmt == Enums::open) { if (pageMgmt == Enums::open) {
bank.openRow = dram_pkt->row; bank.openRow = dram_pkt->row;
bank.freeAt = schedTime + tBURST + accessLat; bank.freeAt = schedTime + tBURST + std::max(accessLat, tCL);
busBusyUntil = bank.freeAt - tCL;
if (!rowHitFlag) if (!rowHitFlag) {
bank.tRASDoneAt = bank.freeAt + tRP; bank.tRASDoneAt = bank.freeAt + tRP;
busBusyUntil = bank.freeAt - tCL - tRCD;
}
} else if (pageMgmt == Enums::close) { } else if (pageMgmt == Enums::close) {
bank.freeAt = schedTime + tBURST + accessLat + tRP + tRP; bank.freeAt = schedTime + tBURST + accessLat + tRP + tRP;
busBusyUntil = bank.freeAt - tRP - tRP - tCL - tRCD;
DPRINTF(DRAMWR, "processWriteEvent::bank.freeAt for " DPRINTF(DRAMWR, "processWriteEvent::bank.freeAt for "
"banks_id %d is %lld\n", "banks_id %d is %lld\n",
dram_pkt->rank * banksPerRank + dram_pkt->bank, dram_pkt->rank * banksPerRank + dram_pkt->bank,
@ -313,13 +316,8 @@ SimpleDRAM::processWriteEvent()
} else } else
panic("Unknown page management policy chosen\n"); panic("Unknown page management policy chosen\n");
// @todo: As of now, write goes on the databus asap, maybe
// be held up at bank. May want to change it to delay the
// schedTime itself.
busBusyUntil = schedTime + tBURST;
DPRINTF(DRAMWR,"Done writing to address %lld\n",dram_pkt->addr); DPRINTF(DRAMWR,"Done writing to address %lld\n",dram_pkt->addr);
DPRINTF(DRAMWR,"schedtime is %lld, tBURST is %lld, " DPRINTF(DRAMWR,"schedtime is %lld, tBURST is %lld, "
"busbusyuntil is %lld\n", "busbusyuntil is %lld\n",
schedTime, tBURST, busBusyUntil); schedTime, tBURST, busBusyUntil);
@ -781,7 +779,8 @@ SimpleDRAM::estimateLatency(DRAMPacket* dram_pkt, Tick inTime)
} else } else
panic("No page management policy chosen\n"); panic("No page management policy chosen\n");
DPRINTF(DRAM, "Returning %lld from estimateLatency()\n",accLat); DPRINTF(DRAM, "Returning < %lld, %lld > from estimateLatency()\n",
bankLat, accLat);
return make_pair(bankLat, accLat); return make_pair(bankLat, accLat);
} }