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Paddle/paddle/fluid/framework/details/multi_devices_graph_pass.cc

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// Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <algorithm>
#include <fstream>
#include <string>
#include <utility>
#include <vector>
#include "paddle/fluid/framework/details/all_reduce_op_handle.h"
#include "paddle/fluid/framework/details/broadcast_op_handle.h"
#include "paddle/fluid/framework/details/computation_op_handle.h"
#include "paddle/fluid/framework/details/data_balance_op_handle.h"
#include "paddle/fluid/framework/details/fused_broadcast_op_handle.h"
#include "paddle/fluid/framework/details/multi_devices_graph_pass.h"
#include "paddle/fluid/framework/details/reduce_op_handle.h"
#include "paddle/fluid/framework/details/rpc_op_handle.h"
#include "paddle/fluid/framework/details/scale_loss_grad_op_handle.h"
#include "paddle/fluid/framework/ir/graph_helper.h"
#include "paddle/fluid/framework/ir/node.h"
#include "paddle/fluid/framework/op_info.h"
#include "paddle/fluid/framework/scope.h"
namespace paddle {
namespace framework {
namespace details {
namespace {
void PolishGraphToSupportDataHazards(ir::Graph *graph) {
for (auto &var_map : graph->Get<GraphVars>(kGraphVars)) {
for (auto &name_pair : var_map) {
if (name_pair.second.size() <= 1) {
continue;
}
auto it_new = name_pair.second.rbegin();
auto it_old = name_pair.second.rbegin();
++it_old;
for (; it_old != name_pair.second.rend(); it_new = it_old, ++it_old) {
OpHandleBase *write_op = (*it_new)->GeneratedOp();
const auto &read_ops = (*it_old)->PendingOps();
for (auto *read_op : read_ops) {
// Manually add a dependency var from read_op to write_op;
if (read_op == write_op) {
// Read Write is the same op.
continue;
}
bool has_dep = false;
for (auto *r_out : read_op->Outputs()) {
for (auto *w_in : write_op->Inputs()) {
if (r_out->Node() == w_in->Node()) {
has_dep = true;
break;
}
}
}
if (has_dep) continue;
auto *dep_var = new DummyVarHandle(graph->CreateControlDepVar());
read_op->AddOutput(dep_var);
write_op->AddInput(dep_var);
graph->Get<GraphDepVars>(kGraphDepVars).emplace(dep_var);
}
}
}
}
}
VarHandle *CreateOrGetLatestVarHandle(ir::Graph *graph, ir::Node *node,
const platform::Place &place,
size_t place_offset) {
auto &var_holders = graph->Get<GraphVars>(kGraphVars)[place_offset];
auto &var_holder = var_holders[node->Name()];
VarHandle *var = nullptr;
if (var_holder.empty()) {
if (node->Var()) {
var = new VarHandle(graph->CreateVarNode(node->Var()), 0, place_offset,
node->Name(), place);
} else {
var = new VarHandle(
graph->CreateEmptyNode(node->Name(), ir::Node::Type::kVariable), 0,
place_offset, node->Name(), place);
}
var_holder.emplace_back(var);
} else {
var = var_holder.rbegin()->get();
}
return var;
}
void CreateOpOutput(ir::Graph *graph, OpHandleBase *op_handle,
ir::Node *new_node, const platform::Place &place,
size_t place_offset) {
auto &vars =
graph->Get<GraphVars>(kGraphVars)[place_offset][new_node->Name()];
size_t version = vars.size();
auto var =
new VarHandle(new_node, version, place_offset, new_node->Name(), place);
vars.emplace_back(var);
op_handle->AddOutput(var);
}
void AddOutputToLeafOps(ir::Graph *graph) {
for (auto &op : graph->Get<GraphOps>(kGraphOps)) {
if (!op->Outputs().empty()) {
continue;
}
auto *dummy_leaf = new DummyVarHandle(graph->CreateControlDepVar());
graph->Get<GraphDepVars>(kGraphDepVars).emplace(dummy_leaf);
op->AddOutput(dummy_leaf);
}
}
} // namespace
static const char kLossVarName[] = "loss_var_name";
static const char kPlaces[] = "places";
static const char kParams[] = "params";
static const char kLocalScopes[] = "local_scopes";
static const char kStrategy[] = "strategy";
void MultiDevSSAGraphBuilder::Init() const {
all_vars_.clear();
balance_vars_.clear();
loss_var_name_ = Get<const std::string>(kLossVarName);
places_ = Get<const std::vector<platform::Place>>(kPlaces);
local_scopes_ = Get<const std::vector<Scope *>>(kLocalScopes);
strategy_ = Get<const BuildStrategy>(kStrategy);
#ifdef PADDLE_WITH_CUDA
nccl_ctxs_ = &Get<platform::NCCLContextMap>("nccl_ctxs");
#endif
for (auto &p : Get<const std::unordered_set<std::string>>(kParams)) {
grad_names_.insert(GradVarName(p));
}
balance_vars_.resize(places_.size(), 0);
if (strategy_.enable_data_balance_ && places_.size() == 1) {
LOG(WARNING) << "It is no need to enable data balance when there is only "
"one place. enable_data_balance is set to False.";
strategy_.enable_data_balance_ = false;
}
}
void MultiDevSSAGraphBuilder::CreateOpHandleIOs(ir::Graph *result,
ir::Node *node,
size_t place_id) const {
auto p = places_[place_id];
auto *op_handle = result->Get<GraphOps>(kGraphOps).back().get();
op_handle->SetDeviceContext(p,
platform::DeviceContextPool::Instance().Get(p));
for (ir::Node *input : node->inputs) {
VarHandle *var = CreateOrGetLatestVarHandle(result, input, p, place_id);
op_handle->AddInput(var);
}
for (ir::Node *output : node->outputs) {
ir::Node *new_node = nullptr;
if (output->Var()) {
new_node = result->CreateVarNode(output->Var());
} else {
new_node =
result->CreateEmptyNode(output->Name(), ir::Node::Type::kVariable);
}
CreateOpOutput(result, op_handle, new_node, p, place_id);
}
}
std::vector<std::string> MultiDevSSAGraphBuilder::FindDistTrainSendVars(
const std::vector<ir::Node *> &nodes) const {
std::vector<std::string> send_vars;
// since parameters are all in block 0,
// it's enough to only scan send ops in block 0
for (auto &node : nodes) {
OpDesc *op = node->Op();
// TODO(Yancey1989): use a graceful method to find send op,
// instead of the the hard code string
if (op->Type() == "send") {
auto op_vars = op->InputArgumentNames();
send_vars.reserve(send_vars.size() +
std::distance(op_vars.begin(), op_vars.end()));
send_vars.insert(send_vars.end(), op_vars.begin(), op_vars.end());
}
}
return send_vars;
}
std::vector<std::string> MultiDevSSAGraphBuilder::FindDistTrainRecvVars(
const std::vector<ir::Node *> &nodes) const {
std::vector<std::string> recv_vars;
for (auto &node : nodes) {
OpDesc *op = node->Op();
// TODO(Yancey1989): use a graceful method to find recv op,
// instead of the hard code string
if (op->Type() == "recv") {
auto op_vars = op->OutputArgumentNames();
recv_vars.reserve(recv_vars.size() +
std::distance(op_vars.begin(), op_vars.end()));
recv_vars.insert(recv_vars.end(), op_vars.begin(), op_vars.end());
}
}
return recv_vars;
}
size_t MultiDevSSAGraphBuilder::GetAppropriateDeviceID(
const std::vector<std::string> &var_names) const {
int64_t numel_sum = 0;
for (auto var_name : var_names) {
if (all_vars_.find(var_name) == all_vars_.end()) continue;
auto var_desc = all_vars_.at(var_name);
PADDLE_ENFORCE_NOT_NULL(var_desc);
auto dim = framework::make_ddim(var_desc->GetShape());
int64_t numel = framework::product(dim);
PADDLE_ENFORCE_GT(numel, 0);
numel_sum += numel;
}
auto smallest =
std::min_element(std::begin(balance_vars_), std::end(balance_vars_));
size_t dev_id =
static_cast<size_t>(std::distance(std::begin(balance_vars_), smallest));
balance_vars_[dev_id] += numel_sum;
return dev_id;
}
// Topology sort the graph nodes from inputs to outputs.
// Since SSAGraphBuilder depends on forward/backward nodes to assign devices
// to parameter/gradients before optimizer ops, topo sort is insufficient. (
// some optimizer ops might not depend on any nodes), we manually move all
// optimizer nodes after last backward nodes.
// However, the assumption by SSAGraphBuilder should be relaxed in the future.
std::vector<ir::Node *> SortOpsAndDelayOptimizeOp(const ir::Graph &graph) {
std::vector<ir::Node *> ret = ir::TopologySortOperations(graph);
size_t last_backward = 0;
for (size_t i = 0; i < ret.size(); ++i) {
if (boost::get<int>(
ret[i]->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleAttrName())) ==
static_cast<int>(OpRole::kBackward)) {
last_backward = i;
}
}
std::vector<ir::Node *> optimize_ops;
std::vector<ir::Node *> sorted_ret;
for (size_t i = 0; i < ret.size(); ++i) {
if (i < last_backward) {
if (static_cast<bool>(boost::get<int>(ret[i]->Op()->GetAttr(
OpProtoAndCheckerMaker::OpRoleAttrName())) &
static_cast<int>(OpRole::kOptimize))) {
optimize_ops.push_back(ret[i]);
} else {
sorted_ret.push_back(ret[i]);
}
} else if (i == last_backward) {
sorted_ret.push_back(ret[i]);
// Verify that no operations before optimize ops depends on optimize ops.
std::unordered_set<ir::Node *> optimize_set(optimize_ops.begin(),
optimize_ops.end());
for (ir::Node *n : sorted_ret) {
for (ir::Node *in : n->inputs) {
for (ir::Node *pre_n : in->inputs) {
PADDLE_ENFORCE(optimize_set.find(pre_n) == optimize_set.end(),
"optimize operations cannot be depended by forward "
"or backward node %s -> %s",
pre_n->Name(), n->Name());
}
}
}
sorted_ret.insert(sorted_ret.end(), optimize_ops.begin(),
optimize_ops.end());
} else {
sorted_ret.push_back(ret[i]);
}
}
return sorted_ret;
}
std::unique_ptr<ir::Graph> MultiDevSSAGraphBuilder::ApplyImpl(
std::unique_ptr<ir::Graph> graph) const {
Init();
// Give the topology sort order and rebuild the graph structure.
std::vector<ir::Node *> sorted_ops = SortOpsAndDelayOptimizeOp(*graph);
auto nodes = graph->ReleaseNodes();
ir::Graph &result = *graph;
for (auto &node : nodes) {
if (node->IsVar() && node->Var()) {
all_vars_.emplace(node->Name(), node->Var());
}
}
std::unordered_set<std::string> og_has_been_broadcast;
// We cannot invoke resize. It is a bug of GCC 4.8
result.Set(kGraphVars, new GraphVars(places_.size()));
result.Set(kGraphDepVars, new GraphDepVars);
result.Set(kGraphOps, new GraphOps);
result.Set(kShardedVarDevice, new ShardedVarDevice);
// find send/recv vars so that we can place the distributed training
// related op in the place 0
auto send_vars = FindDistTrainSendVars(sorted_ops);
auto recv_vars = FindDistTrainRecvVars(sorted_ops);
std::vector<std::unordered_set<std::string>> bcast_var_name_set;
bcast_var_name_set.resize(places_.size());
size_t cur_device_id = 0;
bool is_forwarding = true;
bool is_dist_train = false;
for (ir::Node *node : sorted_ops) {
if (boost::get<int>(
node->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleAttrName())) ==
static_cast<int>(OpRole::kRPC)) {
int op_dev_id = CreateRPCOp(&result, node);
PADDLE_ENFORCE(op_dev_id != -1,
"Can not schedule the RPC operator to the right place.");
if (node->Op()->Type() == "recv") {
auto recv_vars_attr =
boost::get<std::vector<std::string>>(node->Op()->GetNullableAttr(
OpProtoAndCheckerMaker::OpRoleVarAttrName()));
PADDLE_ENFORCE(recv_vars_attr.size() == 2UL); // [parameter, gradient]
if (recv_vars_attr[0].find(".block") == std::string::npos) {
bcast_var_name_set[op_dev_id].emplace(recv_vars_attr[0]);
}
}
is_dist_train = true;
} else if (boost::get<int>(node->Op()->GetAttr(
OpProtoAndCheckerMaker::OpRoleAttrName())) ==
static_cast<int>(OpRole::kDist)) {
int op_dev_id = CreateDistTrainOp(&result, node);
if (node->Op()->Type() == "concat") {
auto origin_param_name = node->Op()->OutputArgumentNames()[0];
bcast_var_name_set[op_dev_id].emplace(origin_param_name);
}
} else if (IsScaleLossOp(node)) {
// user can customize loss@grad if not use_default_grad_scale_
if (strategy_.gradient_scale_ !=
BuildStrategy::GradientScaleStrategy::kCustomized) {
// TODO(paddle-dev): Why is there no input for this op_handle?
auto loss_grad_name = node->Op()->OutputArgumentNames()[0];
CreateScaleLossGradOp(&result, loss_grad_name, node->outputs[0]);
}
// This assumes the backward generating code will ensure IsScaleLossOp
// is true only for the op that scale the final scalar loss.
// It also assumes backward op will always follow the forward op in
// the block.
is_forwarding = false;
} else {
int op_dev_id = GetOpDeviceID(result, node);
if (op_dev_id != -1) { // This op only runs on one specific device.
CreateComputationalOp(&result, node, op_dev_id);
for (ir::Node *n : node->outputs) {
graph->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(n->Name(), op_dev_id);
}
} else {
// This op runs on all devices, and its output may have parameter's
// gradients.
// TODO(paddle-dev): Why is so special about "read" op?
if (node->Op()->Type() == "read" && strategy_.enable_data_balance_) {
node->Op()->SetAttr("throw_eof_exp", false);
CreateComputationalOps(&result, node, places_.size());
const auto &data_var_names = node->Op()->Output("Out");
InsertDataBalanceOp(&result, data_var_names);
} else {
CreateComputationalOps(&result, node, places_.size());
}
if (!is_forwarding && places_.size() > 1) {
// Currently, we assume that once gradient is generated, it can be
// broadcast, and each gradient is only broadcast once.
if (static_cast<bool>(boost::get<int>(node->Op()->GetAttr(
OpProtoAndCheckerMaker::OpRoleAttrName())) &
static_cast<int>(OpRole::kBackward))) {
try {
auto backward_vars = boost::get<std::vector<std::string>>(
node->Op()->GetNullableAttr(
OpProtoAndCheckerMaker::OpRoleVarAttrName()));
PADDLE_ENFORCE_EQ(backward_vars.size() % 2, 0);
for (size_t i = 0; i < backward_vars.size(); i += 2) {
auto &p_name = backward_vars[i];
auto &g_name = backward_vars[i + 1];
VLOG(100) << "Bcast " << g_name << " for parameter " << p_name;
switch (strategy_.reduce_) {
case BuildStrategy::ReduceStrategy::kReduce:
cur_device_id = GetAppropriateDeviceID({g_name});
CreateReduceOp(&result, g_name, cur_device_id);
graph->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(g_name, cur_device_id);
if (!is_dist_train) {
bcast_var_name_set[cur_device_id].emplace(p_name);
}
break;
case BuildStrategy::ReduceStrategy::kAllReduce:
if (IsSparseGradient(g_name)) {
CreateReduceOp(&result, g_name, 0);
CreateBroadcastOp(&result, g_name, 0);
} else {
InsertAllReduceOp(&result, g_name);
}
break;
default:
LOG(FATAL) << "Unknown reduce strategy ";
break;
}
}
} catch (boost::bad_get e) {
}
}
}
}
}
}
bool use_gpu = false;
#ifdef PADDLE_WITH_CUDA
use_gpu = nccl_ctxs_ != nullptr;
#endif
// Insert broadcast operators principle:
// 1. Broadcast optimized parameters in Reduce strategy;
// 2. No need broadcast optimized parameters in AllReduce strategy because of
// the optimization sub-graph would be run on every GPU;
// 3. Allways broadcast received parameters in Distribute Training.
if ((use_gpu &&
strategy_.reduce_ == BuildStrategy::ReduceStrategy::kReduce) ||
is_dist_train) {
if (strategy_.fuse_broadcast_op_) {
CreateFusedBroadcastOp(&result, bcast_var_name_set);
} else {
for (size_t dev_id = 0; dev_id < bcast_var_name_set.size(); ++dev_id) {
auto &to_bcast_set = bcast_var_name_set[dev_id];
for (auto &bcast_name : to_bcast_set) {
CreateBroadcastOp(&result, bcast_name, dev_id);
}
}
}
}
/*
Dependency graph has been constructed. However, there are still data
hazards need to be handled.
*/
PolishGraphToSupportDataHazards(&result);
/*
* Only variables should be the leaves of graph.
*/
AddOutputToLeafOps(&result);
PADDLE_ENFORCE(!ir::HasCircle(result));
return graph;
}
bool MultiDevSSAGraphBuilder::IsSparseGradient(const std::string &og) const {
PADDLE_ENFORCE(all_vars_.count(og) != 0);
if (all_vars_.at(og)->GetType() == proto::VarType::SELECTED_ROWS) {
return true;
}
return false;
}
void MultiDevSSAGraphBuilder::SetCommunicationContext(
OpHandleBase *op_handle, const platform::Place &p) const {
#ifdef PADDLE_WITH_CUDA
if (nccl_ctxs_ == nullptr) {
op_handle->SetDeviceContext(p,
platform::DeviceContextPool::Instance().Get(p));
}
#else
op_handle->SetDeviceContext(p,
platform::DeviceContextPool::Instance().Get(p));
#endif
}
void MultiDevSSAGraphBuilder::CreateBroadcastOp(ir::Graph *result,
const std::string &p_name,
size_t src_dev_id) const {
#ifdef PADDLE_WITH_CUDA
auto *op_handle = new BroadcastOpHandle(
result->CreateEmptyNode("broadcast", ir::Node::Type::kOperation),
local_scopes_, places_, nccl_ctxs_);
#else
auto *op_handle = new BroadcastOpHandle(
result->CreateEmptyNode("broadcast", ir::Node::Type::kOperation),
local_scopes_, places_);
#endif
result->Get<GraphOps>(kGraphOps).emplace_back(op_handle);
auto *in =
result->Get<GraphVars>(kGraphVars).at(src_dev_id).at(p_name).back().get();
op_handle->AddInput(in);
for (size_t i = 0; i < places_.size(); ++i) {
auto &p = places_[i];
SetCommunicationContext(op_handle, p);
auto &vars = result->Get<GraphVars>(kGraphVars).at(i).at(p_name);
auto *out_var = new VarHandle(
result->CreateEmptyNode(p_name, ir::Node::Type::kVariable), vars.size(),
i, p_name, p);
vars.emplace_back(out_var);
op_handle->AddOutput(out_var);
}
}
void MultiDevSSAGraphBuilder::CreateFusedBroadcastOp(
ir::Graph *result,
const std::vector<std::unordered_set<std::string>> &bcast_varnames) const {
#ifdef PADDLE_WITH_CUDA
auto *op_handle = new FusedBroadcastOpHandle(
result->CreateEmptyNode("fused_broadcast", ir::Node::Type::kOperation),
local_scopes_, places_, nccl_ctxs_);
#else
auto *op_handle = new FusedBroadcastOpHandle(
result->CreateEmptyNode("fused_broadcast", ir::Node::Type::kOperation),
local_scopes_, places_);
#endif
result->Get<GraphOps>(kGraphOps).emplace_back(op_handle);
for (size_t i = 0; i < places_.size(); ++i) {
auto &p = places_[i];
SetCommunicationContext(op_handle, p);
}
for (size_t dev_id = 0; dev_id < bcast_varnames.size(); ++dev_id) {
for (auto &p_name : bcast_varnames[dev_id]) {
auto *in =
result->Get<GraphVars>(kGraphVars).at(dev_id).at(p_name).back().get();
op_handle->AddInput(in);
for (size_t out_dev_id = 0; out_dev_id < places_.size(); ++out_dev_id) {
auto &p = places_[out_dev_id];
auto &vars =
result->Get<GraphVars>(kGraphVars).at(out_dev_id).at(p_name);
auto *out_var = new VarHandle(
result->CreateEmptyNode(p_name, ir::Node::Type::kVariable),
vars.size(), out_dev_id, p_name, p);
vars.emplace_back(out_var);
op_handle->AddOutput(out_var);
}
}
}
}
void MultiDevSSAGraphBuilder::CreateComputationalOp(ir::Graph *result,
ir::Node *node,
int dev_id) const {
result->Get<GraphOps>(kGraphOps).emplace_back(
new ComputationOpHandle(result->CreateOpNode(node->Op()),
local_scopes_[dev_id], places_[dev_id]));
CreateOpHandleIOs(result, node, dev_id);
}
void MultiDevSSAGraphBuilder::InsertAllReduceOp(ir::Graph *result,
const std::string &og) const {
#ifdef PADDLE_WITH_CUDA
result->Get<GraphOps>(kGraphOps).emplace_back(new AllReduceOpHandle(
result->CreateEmptyNode("allreduce", ir::Node::Type::kOperation),
local_scopes_, places_, nccl_ctxs_));
#else
result->Get<GraphOps>(kGraphOps).emplace_back(new AllReduceOpHandle(
result->CreateEmptyNode("allreduce", ir::Node::Type::kOperation),
local_scopes_, places_));
#endif
auto *op_handle = result->Get<GraphOps>(kGraphOps).back().get();
for (size_t i = 0; i < places_.size(); ++i) {
auto &p = places_[i];
SetCommunicationContext(op_handle, p);
auto &vars = result->Get<GraphVars>(kGraphVars)[i][og];
PADDLE_ENFORCE(!vars.empty());
auto &prev_grad = vars.back();
op_handle->AddInput(prev_grad.get());
auto var =
new VarHandle(result->CreateEmptyNode(og, ir::Node::Type::kVariable),
vars.size(), i, og, p);
vars.emplace_back(var);
op_handle->AddOutput(var);
}
}
void MultiDevSSAGraphBuilder::InsertDataBalanceOp(
ir::Graph *result, const std::vector<std::string> &datas) const {
#ifdef PADDLE_WITH_CUDA
result->Get<GraphOps>(kGraphOps).emplace_back(new DataBalanceOpHandle(
result->CreateEmptyNode("data_balance", ir::Node::Type::kOperation),
local_scopes_, places_, nccl_ctxs_));
#else
result->Get<GraphOps>(kGraphOps).emplace_back(new DataBalanceOpHandle(
result->CreateEmptyNode("data_balance", ir::Node::Type::kOperation),
local_scopes_, places_));
#endif
auto *op_handle = result->Get<GraphOps>(kGraphOps).back().get();
for (size_t i = 0; i < places_.size(); ++i) {
auto &p = places_[i];
SetCommunicationContext(op_handle, p);
for (const std::string &d_name : datas) {
auto &vars = result->Get<GraphVars>(kGraphVars)[i][d_name];
PADDLE_ENFORCE(!vars.empty());
op_handle->AddInput(vars.back().get());
auto var = new VarHandle(
result->CreateEmptyNode(d_name, ir::Node::Type::kVariable),
vars.size(), i, d_name, p);
vars.emplace_back(var);
op_handle->AddOutput(var);
}
}
}
int MultiDevSSAGraphBuilder::GetOpDeviceID(const ir::Graph &graph,
ir::Node *node) const {
if (strategy_.reduce_ != BuildStrategy::ReduceStrategy::kReduce) {
return -1;
}
int op_role = boost::get<int>(
node->Op()->GetAttr(framework::OpProtoAndCheckerMaker::OpRoleAttrName()));
if (op_role != static_cast<int>(framework::OpRole::kOptimize)) {
return -1;
}
auto param_grad = boost::get<std::vector<std::string>>(
node->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleVarAttrName()));
PADDLE_ENFORCE_EQ(param_grad.size(), 2U);
int dev_id = GetVarDeviceID(graph, param_grad[1]);
PADDLE_ENFORCE_NE(dev_id, -1, "dev_id should not be -1.[%s, %s, %s]",
node->Op()->Type(), param_grad[0], param_grad[1]);
return dev_id;
}
int MultiDevSSAGraphBuilder::GetVarDeviceID(const ir::Graph &graph,
const std::string &varname) const {
auto &sharded_var_device = graph.Get<ShardedVarDevice>(kShardedVarDevice);
auto got = sharded_var_device.find(varname);
return got == sharded_var_device.end() ? -1 : got->second;
}
void MultiDevSSAGraphBuilder::CreateScaleLossGradOp(
ir::Graph *result, const std::string &loss_grad_name,
ir::Node *out_var_node) const {
for (size_t i = 0; i < places_.size(); ++i) {
// Insert ScaleCost OpHandle
auto *dev_ctx = platform::DeviceContextPool::Instance().Get(places_[i]);
auto *op_handle = new ScaleLossGradOpHandle(
result->CreateEmptyNode("scale_loss_grad", ir::Node::Type::kOperation),
local_scopes_.size(), local_scopes_[i], places_[i], dev_ctx);
result->Get<GraphOps>(kGraphOps).emplace_back(op_handle);
// FIXME: Currently ScaleLossGradOp only use device_count as scale
// factor. So it does not depend on any other operators.
// VarHandle *loss = GetVarHandle(loss_var_name, place);
// loss->pending_ops_.emplace_back(op_handle);
// op_handle->inputs_.emplace_back(loss);
CreateOpOutput(result, op_handle,
result->CreateVarNode(out_var_node->Var()), places_[i], i);
}
}
void MultiDevSSAGraphBuilder::CreateComputationalOps(ir::Graph *result,
ir::Node *node,
size_t num_places) const {
for (size_t scope_idx = 0; scope_idx < num_places; ++scope_idx) {
auto p = places_[scope_idx];
auto s = local_scopes_[scope_idx];
result->Get<GraphOps>(kGraphOps).emplace_back(
new ComputationOpHandle(result->CreateOpNode(node->Op()), s, p));
CreateOpHandleIOs(result, node, scope_idx);
}
}
VarHandle *MultiDevSSAGraphBuilder::CreateReduceOp(ir::Graph *result,
const std::string &og,
int dst_dev_id) const {
#ifdef PADDLE_WITH_CUDA
result->Get<GraphOps>(kGraphOps).emplace_back(new ReduceOpHandle(
result->CreateEmptyNode("reduce", ir::Node::Type::kOperation),
local_scopes_, places_, nccl_ctxs_));
#else
result->Get<GraphOps>(kGraphOps).emplace_back(new ReduceOpHandle(
result->CreateEmptyNode("reduce", ir::Node::Type::kOperation),
local_scopes_, places_));
#endif
auto *op_handle = result->Get<GraphOps>(kGraphOps).back().get();
for (size_t i = 0; i < places_.size(); ++i) {
auto &p = places_[i];
SetCommunicationContext(op_handle, p);
auto &vars = result->Get<GraphVars>(kGraphVars)[i][og];
PADDLE_ENFORCE(!vars.empty());
auto &prev_grad = vars.back();
op_handle->AddInput(prev_grad.get());
}
auto &vars = result->Get<GraphVars>(kGraphVars)[dst_dev_id][og];
auto var =
new VarHandle(result->CreateEmptyNode(og, ir::Node::Type::kVariable),
vars.size(), dst_dev_id, og, places_[dst_dev_id]);
vars.emplace_back(var);
op_handle->AddOutput(var);
return var;
}
int MultiDevSSAGraphBuilder::CreateDistTrainOp(ir::Graph *result,
ir::Node *node) const {
int op_dev_id = -1;
std::vector<std::string> input_var_names;
std::vector<std::string> output_var_names;
for (ir::Node *input : node->inputs) {
input_var_names.push_back(input->Name());
}
for (ir::Node *output : node->outputs) {
output_var_names.push_back(output->Name());
}
if (node->Op()->Type() == "split_byref" ||
node->Op()->Type() == "split_selected_rows" ||
node->Op()->Type() == "split_ids") {
// TODO(paddle-dev): getting the first var is not safe.
op_dev_id = GetVarDeviceID(*result, input_var_names[0]);
if (strategy_.reduce_ == BuildStrategy::ReduceStrategy::kAllReduce) {
op_dev_id = GetAppropriateDeviceID(input_var_names);
for (auto &varname : input_var_names) {
result->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(varname, op_dev_id);
}
}
for (auto &varname : output_var_names) {
result->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(varname, op_dev_id);
}
} else if (node->Op()->Type() == "concat") {
op_dev_id = GetVarDeviceID(*result, input_var_names[0]);
for (auto &varname : output_var_names) {
result->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(varname, op_dev_id);
}
} else {
LOG(ERROR) << "got unexpected dist op: " << node->Op()->Type();
PADDLE_THROW(
"the distribute training related op should be in [split_byref, "
"concat].");
}
PADDLE_ENFORCE(op_dev_id != -1,
"can not find right place for distributed op: %s",
node->Op()->Type());
CreateComputationalOp(result, node, op_dev_id);
return op_dev_id;
}
void SetOpInputsAllPlaces(ir::Graph *result, ir::Node *node, int num_places) {
auto *op_handle = result->Get<GraphOps>(kGraphOps).back().get();
for (ir::Node *input : node->inputs) {
VarHandle *var = nullptr;
for (int place_offset = 0; place_offset < num_places; ++place_offset) {
auto &var_holders = result->Get<GraphVars>(kGraphVars)[place_offset];
auto &var_holder = var_holders[input->Name()];
if (!var_holder.empty()) {
var = var_holder.rbegin()->get();
op_handle->AddInput(var);
}
}
}
}
// Create RPC related op handles that connects its in ops and out ops.
int MultiDevSSAGraphBuilder::CreateRPCOp(ir::Graph *result,
ir::Node *node) const {
int op_dev_id = -1;
if (node->Op()->Type() == "send") {
// TODO(paddle-dev): getting the first var is not safe.
op_dev_id = GetVarDeviceID(*result, node->inputs[0]->Name());
PADDLE_ENFORCE(!ir::IsControlDepVar(*node->inputs[0]),
"This hack no longer holds, please fix.");
// the variable name which contains .block means it was splited by
// split_byref op
if (strategy_.reduce_ == BuildStrategy::ReduceStrategy::kAllReduce &&
node->inputs[0]->Name().find(".block") == std::string::npos) {
std::vector<std::string> input_var_names;
for (ir::Node *n : node->inputs) {
input_var_names.push_back(n->Name());
}
auto send_param_grad = boost::get<std::vector<std::string>>(
node->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleVarAttrName()));
PADDLE_ENFORCE_EQ(send_param_grad.size(), 2U);
op_dev_id = GetAppropriateDeviceID({send_param_grad[1]});
VLOG(100) << "send grad " << input_var_names[0] << " origin "
<< send_param_grad[1] << " place: " << op_dev_id;
for (auto &varname : input_var_names) {
result->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(varname, op_dev_id);
}
result->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(send_param_grad[1], op_dev_id);
}
} else if (node->Op()->Type() == "recv") {
std::vector<std::string> output_var_names;
for (ir::Node *n : node->outputs) {
output_var_names.push_back(n->Name());
}
auto recv_param_grad = boost::get<std::vector<std::string>>(
node->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleVarAttrName()));
if (recv_param_grad.size() == 2U) {
op_dev_id = GetVarDeviceID(*result, recv_param_grad[1]);
VLOG(100) << "recv param " << recv_param_grad[0]
<< " get grad place: " << recv_param_grad[1]
<< " place: " << op_dev_id;
} else {
op_dev_id = GetAppropriateDeviceID(output_var_names);
}
for (auto &varname : output_var_names) {
result->Get<ShardedVarDevice>(kShardedVarDevice)
.emplace(varname, op_dev_id);
}
} else {
// send_barrier, fetch_barrier will run on place 0;
op_dev_id = 0;
}
PADDLE_ENFORCE(op_dev_id != -1, "can not find the right place for rpc op: %s",
node->Op()->Type());
result->Get<GraphOps>(kGraphOps).emplace_back(new RPCOpHandle(
result->CreateOpNode(node->Op()), *node->Op(), local_scopes_[op_dev_id],
node->Op()->Type(), places_[op_dev_id]));
if (node->Op()->Type() == "send") {
CreateOpHandleIOs(result, node, op_dev_id);
} else {
// send_barrier, recv, fetch_barrier's inputs are deps var, get them from
// all places
auto p = places_[op_dev_id];
auto *op_handle = result->Get<GraphOps>(kGraphOps).back().get();
op_handle->SetDeviceContext(p,
platform::DeviceContextPool::Instance().Get(p));
SetOpInputsAllPlaces(result, node, places_.size());
for (ir::Node *output : node->outputs) {
int outvar_dev_id = op_dev_id;
if (node->Op()->Type() == "fetch_barrier") {
outvar_dev_id = GetVarDeviceID(*result, output->Name());
PADDLE_ENFORCE_NE(outvar_dev_id, -1);
}
p = places_[outvar_dev_id];
ir::Node *new_node = nullptr;
if (output->Var()) {
new_node = result->CreateVarNode(output->Var());
} else {
new_node =
result->CreateEmptyNode(output->Name(), ir::Node::Type::kVariable);
}
CreateOpOutput(result, op_handle, new_node, p, outvar_dev_id);
}
}
return op_dev_id;
}
bool MultiDevSSAGraphBuilder::IsScaleLossOp(ir::Node *node) const {
return boost::get<int>(
node->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleAttrName())) ==
(static_cast<int>(OpRole::kBackward) |
static_cast<int>(OpRole::kLoss)) &&
!loss_var_name_.empty(); // If loss_var is empty. This is test mode
}
} // namespace details
} // namespace framework
} // namespace paddle
REGISTER_PASS(multi_devices_pass,
paddle::framework::details::MultiDevSSAGraphBuilder)
.RequirePassAttr(paddle::framework::details::kLossVarName)
.RequirePassAttr(paddle::framework::details::kPlaces)
.RequirePassAttr(paddle::framework::details::kParams)
.RequirePassAttr(paddle::framework::details::kLocalScopes)
.RequirePassAttr(paddle::framework::details::kStrategy);