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authorAndreas Hansson <andreas.hansson@arm.com>2014-03-23 11:12:05 -0400
committerAndreas Hansson <andreas.hansson@arm.com>2014-03-23 11:12:05 -0400
commitbc83eb2197d94748a8845185ddd4ae33a0b8487a (patch)
treeec19c8f871348597c8bcbe83e766c91eb8e79645
parent116985d661f6383bf2b61fa9b9d3df96e52fdb6d (diff)
downloadgem5-bc83eb2197d94748a8845185ddd4ae33a0b8487a.tar.xz
mem: Fix bug in DRAM bytes per activate
This patch ensures that we do not sample the bytes per activate when the row has already been closed.
-rw-r--r--src/mem/simple_dram.cc21
1 files changed, 17 insertions, 4 deletions
diff --git a/src/mem/simple_dram.cc b/src/mem/simple_dram.cc
index 505431772..42e36486a 100644
--- a/src/mem/simple_dram.cc
+++ b/src/mem/simple_dram.cc
@@ -1066,7 +1066,6 @@ SimpleDRAM::doDRAMAccess(DRAMPacket* dram_pkt)
// Update bank state
if (pageMgmt == Enums::open || pageMgmt == Enums::open_adaptive) {
- bank.openRow = dram_pkt->row;
bank.freeAt = curTick() + addDelay + accessLat;
// If you activated a new row do to this access, the next access
@@ -1077,9 +1076,18 @@ SimpleDRAM::doDRAMAccess(DRAMPacket* dram_pkt)
bank.tRASDoneAt = actTick + tRAS;
recordActivate(actTick, dram_pkt->rank, dram_pkt->bank);
- // sample the number of bytes accessed and reset it as
- // we are now closing this row
- bytesPerActivate.sample(bank.bytesAccessed);
+ // if we closed an open row as a result of this access,
+ // then sample the number of bytes accessed before
+ // resetting it
+ if (bank.openRow != -1)
+ bytesPerActivate.sample(bank.bytesAccessed);
+
+ // update the open row
+ bank.openRow = dram_pkt->row;
+
+ // start counting anew, this covers both the case when we
+ // auto-precharged, and when this access is forced to
+ // precharge
bank.bytesAccessed = 0;
bank.rowAccesses = 0;
}
@@ -1137,6 +1145,11 @@ SimpleDRAM::doDRAMAccess(DRAMPacket* dram_pkt)
DPRINTF(DRAM, "All banks precharged at tick: %ld\n",
startTickPrechargeAll);
}
+
+ // sample the bytes per activate here since we are closing
+ // the page
+ bytesPerActivate.sample(bank.bytesAccessed);
+
DPRINTF(DRAM, "Auto-precharged bank: %d\n", dram_pkt->bankId);
}