Skip to content

Commit

Permalink
[CtrlPktE2E] A number of fixups around forcing Pathfinder routing con…
Browse files Browse the repository at this point in the history 
…sistency (#1784)
  • Loading branch information
@erwei-xilinx
erwei-xilinx authored Sep 24, 2024
1 parent d630495 commit 741c201
Show file tree
Hide file tree
Showing 3 changed files with 65 additions and 37 deletions.
12 changes: 9 additions & 3 deletions include/aie/Dialect/AIE/Transforms/AIEPathFinder.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,8 @@ using SwitchboxConnect = struct SwitchboxConnect {
std::vector<std::vector<int>> packetFlowCount;
// only sharing the channel with the same packet group id
std::vector<std::vector<int>> packetGroupId;
// flags indicating priority routings
std::vector<std::vector<bool>> isPriority;

// resize the matrices to the size of srcPorts and dstPorts
void resize() {
Expand All @@ -63,6 +65,8 @@ using SwitchboxConnect = struct SwitchboxConnect {
packetFlowCount.resize(srcPorts.size(),
std::vector<int>(dstPorts.size(), 0));
packetGroupId.resize(srcPorts.size(), std::vector<int>(dstPorts.size(), 0));
isPriority.resize(srcPorts.size(),
std::vector<bool>(dstPorts.size(), false));
}

// update demand at the beginning of each dijkstraShortestPaths iteration
Expand All @@ -77,11 +81,13 @@ using SwitchboxConnect = struct SwitchboxConnect {
}
}

// inside each dijkstraShortestPaths interation, bump demand when exceeds
// capacity
// Inside each dijkstraShortestPaths interation, bump demand when exceeds
// capacity. If isPriority is true, then set demand to INF to ensure routing
// consistency for prioritized flows
void bumpDemand(size_t i, size_t j) {
if (usedCapacity[i][j] >= MAX_CIRCUIT_STREAM_CAPACITY) {
demand[i][j] *= DEMAND_COEFF;
demand[i][j] *=
isPriority[i][j] ? std::numeric_limits<int>::max() : DEMAND_COEFF;
}
}
};
Expand Down
88 changes: 55 additions & 33 deletions lib/Dialect/AIE/Transforms/AIEPathFinder.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,26 +34,10 @@ LogicalResult DynamicTileAnalysis::runAnalysis(DeviceOp &device) {

pathfinder->initialize(maxCol, maxRow, device.getTargetModel());

// for each flow in the device, add it to pathfinder
// each source can map to multiple different destinations (fanout)
for (FlowOp flowOp : device.getOps<FlowOp>()) {
TileOp srcTile = cast<TileOp>(flowOp.getSource().getDefiningOp());
TileOp dstTile = cast<TileOp>(flowOp.getDest().getDefiningOp());
TileID srcCoords = {srcTile.colIndex(), srcTile.rowIndex()};
TileID dstCoords = {dstTile.colIndex(), dstTile.rowIndex()};
Port srcPort = {flowOp.getSourceBundle(), flowOp.getSourceChannel()};
Port dstPort = {flowOp.getDestBundle(), flowOp.getDestChannel()};
LLVM_DEBUG(llvm::dbgs()
<< "\tAdding Flow: (" << srcCoords.col << ", " << srcCoords.row
<< ")" << stringifyWireBundle(srcPort.bundle) << srcPort.channel
<< " -> (" << dstCoords.col << ", " << dstCoords.row << ")"
<< stringifyWireBundle(dstPort.bundle) << dstPort.channel
<< "\n");
pathfinder->addFlow(srcCoords, srcPort, dstCoords, dstPort,
/*isPktFlow*/ false, /*isPriorityFlow*/ false);
}

// Control packet flows to be routed (as prioritized routings)
// For each flow (circuit + packet) in the device, add it to pathfinder. Each
// source can map to multiple different destinations (fanout). Control packet
// flows to be routed (as prioritized routings). Then followed by normal
// packet flows.
for (PacketFlowOp pktFlowOp : device.getOps<PacketFlowOp>()) {
Region &r = pktFlowOp.getPorts();
Block &b = r.front();
Expand Down Expand Up @@ -92,6 +76,24 @@ LogicalResult DynamicTileAnalysis::runAnalysis(DeviceOp &device) {
pathfinder->sortFlows(device.getTargetModel().columns(),
device.getTargetModel().rows());

// Add circuit flows.
for (FlowOp flowOp : device.getOps<FlowOp>()) {
TileOp srcTile = cast<TileOp>(flowOp.getSource().getDefiningOp());
TileOp dstTile = cast<TileOp>(flowOp.getDest().getDefiningOp());
TileID srcCoords = {srcTile.colIndex(), srcTile.rowIndex()};
TileID dstCoords = {dstTile.colIndex(), dstTile.rowIndex()};
Port srcPort = {flowOp.getSourceBundle(), flowOp.getSourceChannel()};
Port dstPort = {flowOp.getDestBundle(), flowOp.getDestChannel()};
LLVM_DEBUG(llvm::dbgs()
<< "\tAdding Flow: (" << srcCoords.col << ", " << srcCoords.row
<< ")" << stringifyWireBundle(srcPort.bundle) << srcPort.channel
<< " -> (" << dstCoords.col << ", " << dstCoords.row << ")"
<< stringifyWireBundle(dstPort.bundle) << dstPort.channel
<< "\n");
pathfinder->addFlow(srcCoords, srcPort, dstCoords, dstPort,
/*isPktFlow*/ false, /*isPriorityFlow*/ false);
}

// add existing connections so Pathfinder knows which resources are
// available search all existing SwitchBoxOps for exising connections
for (SwitchboxOp switchboxOp : device.getOps<SwitchboxOp>()) {
Expand Down Expand Up @@ -353,19 +355,37 @@ void Pathfinder::sortFlows(const int maxCol, const int maxRow) {
else
normalFlows.push_back(f);
}
// Get unique int identifier from a vector if pairs of int properties and
// their maximums.
auto getUniqueIdFromVecOfProperties =
[](std::vector<std::pair<int, int>> propertiesAndLimits) {
int uniqueId = 0;
int multiplier = 1;
for (auto pair : propertiesAndLimits) {
uniqueId += pair.first * multiplier;
multiplier *= pair.second;
}
return uniqueId;
};
std::sort(priorityFlows.begin(), priorityFlows.end(),
[maxCol, maxRow](const auto &lhs, const auto &rhs) {
int lhsUniqueID = lhs.src.coords.col;
lhsUniqueID += lhs.src.coords.row * maxCol;
lhsUniqueID += maxRow * maxCol;
lhsUniqueID += getWireBundleAsInt(lhs.src.port.bundle);
lhsUniqueID += AIE::getMaxEnumValForWireBundle();
lhsUniqueID += lhs.src.port.channel;
int rhsUniqueID = rhs.src.coords.col;
rhsUniqueID += rhs.src.coords.row * maxCol;
rhsUniqueID += maxRow * maxCol;
rhsUniqueID += getWireBundleAsInt(rhs.src.port.bundle);
rhsUniqueID += rhs.src.port.channel;
[maxCol, maxRow, getUniqueIdFromVecOfProperties](const auto &lhs,
const auto &rhs) {
// List of properties used in sorting: src col, src row, src
// wirebundle and src channel.
std::vector<std::pair<int, int>> lhsProperties = {
{lhs.src.coords.col, maxCol},
{lhs.src.coords.row, maxRow},
{getWireBundleAsInt(lhs.src.port.bundle),
AIE::getMaxEnumValForWireBundle()},
{lhs.src.port.channel, /*don't care*/ 0}};
int lhsUniqueID = getUniqueIdFromVecOfProperties(lhsProperties);
std::vector<std::pair<int, int>> rhsProperties = {
{rhs.src.coords.col, maxCol},
{rhs.src.coords.row, maxRow},
{getWireBundleAsInt(rhs.src.port.bundle),
AIE::getMaxEnumValForWireBundle()},
{rhs.src.port.channel, /*don't care*/ 0}};
int rhsUniqueID = getUniqueIdFromVecOfProperties(rhsProperties);
return lhsUniqueID < rhsUniqueID;
});
flows = priorityFlows;
Expand Down Expand Up @@ -507,6 +527,7 @@ Pathfinder::findPaths(const int maxIterations) {
for (size_t j = 0; j < sb.dstPorts.size(); j++) {
sb.usedCapacity[i][j] = 0;
sb.overCapacity[i][j] = 0;
sb.isPriority[i][j] = false;
}
}
}
Expand Down Expand Up @@ -562,7 +583,7 @@ Pathfinder::findPaths(const int maxIterations) {
// update used_capacity for the path between them

for (const auto &[_, flows] : groupedFlows) {
for (const auto &[packetGroupId, _, src, dsts] : flows) {
for (const auto &[packetGroupId, isPriority, src, dsts] : flows) {
// Use dijkstra to find path given current demand from the start
// switchbox; find the shortest paths to each other switchbox. Output is
// in the predecessor map, which must then be processed to get
Expand Down Expand Up @@ -593,6 +614,7 @@ Pathfinder::findPaths(const int maxIterations) {
std::find(sb.dstPorts.begin(), sb.dstPorts.end(), curr.port));
assert(i < sb.srcPorts.size());
assert(j < sb.dstPorts.size());
sb.isPriority[i][j] = isPriority;
if (packetGroupId >= 0 &&
(sb.packetGroupId[i][j] == -1 ||
sb.packetGroupId[i][j] == packetGroupId)) {
Expand Down
2 changes: 1 addition & 1 deletion test/create-packet-flows/test_congestion1.mlir
View file
Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@
// CHECK1: aie.flow(%[[TILE_0_4]], DMA : 0, %[[TILE_0_1]], DMA : 2)
// CHECK1: aie.flow(%[[TILE_0_5]], DMA : 0, %[[TILE_0_1]], DMA : 3)

// CHECK2: "total_path_length": 14
// CHECK2: "total_path_length": 19

module {
aie.device(npu1_2col) {
Expand Down

0 comments on commit 741c201

Please sign in to comment.