TensorRT-LLMs/cpp/tensorrt_llm/thop/reducescatterOp.cpp
Yihan Wang 9df4dad3b6
[None][fix] Introduce inline namespace to avoid symbol collision (#9541)
Signed-off-by: Yihan Wang <yihwang@nvidia.com>
2025-12-12 23:32:15 +08:00

313 lines
10 KiB
C++

/*
* SPDX-FileCopyrightText: Copyright (c) 1993-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* 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 "tensorrt_llm/common/opUtils.h"
#include "tensorrt_llm/runtime/torchUtils.h"
#include "tensorrt_llm/runtime/utils/mpiUtils.h"
#include "tensorrt_llm/runtime/utils/pgUtils.h"
#include <NvInferRuntime.h>
#include <c10/cuda/CUDAStream.h>
#include <torch/extension.h>
#if ENABLE_MULTI_DEVICE
#include <nccl.h>
#include <torch/csrc/distributed/c10d/ProcessGroupNCCL.hpp>
#endif // ENABLE_MULTI_DEVICE
#include <cassert>
#include <set>
#include <vector>
using tensorrt_llm::pg_utils::PgHelper;
TRTLLM_NAMESPACE_BEGIN
namespace torch_ext
{
#if ENABLE_MULTI_DEVICE
namespace
{
class ReducescatterOp
{
public:
ReducescatterOp(std::set<int> group)
: mGroup(std::move(group))
{
}
~ReducescatterOp() = default;
int initialize()
{
TLLM_LOG_TRACE("%s start for rank %d", __PRETTY_FUNCTION__, -1);
mNcclComm = getComm(mGroup);
TLLM_LOG_TRACE("%s stop for rank %d", __PRETTY_FUNCTION__, -1);
return 0;
}
std::vector<torch::Tensor> run_list(torch::TensorList input_list, torch::optional<torch::List<int64_t>> sizes)
{
TLLM_CHECK_WITH_INFO(mNcclComm.get() != nullptr, "mNcclComm should be initialized before used");
bool use_nccl_reducescatter = !sizes.has_value()
|| std::all_of(sizes.value().begin(), sizes.value().end(),
[&sizes](int64_t size) { return size == sizes.value()[0]; });
int groupRank = 0;
if (sizes.has_value())
{
auto rank = COMM_SESSION.getRank();
for (auto const& currentRank : mGroup)
{
if (rank == currentRank)
break;
++groupRank;
}
TLLM_CHECK(static_cast<size_t>(groupRank) < mGroup.size());
}
std::vector<torch::Tensor> output_list;
output_list.reserve(input_list.size());
ncclGroupStart();
for (auto const& input : input_list)
{
auto stream = at::cuda::getCurrentCUDAStream(input.get_device());
auto type = tensorrt_llm::runtime::TorchUtils::dataType(input.scalar_type());
std::vector<int64_t> outputShape = input.sizes().vec();
if (sizes.has_value())
{
outputShape[0] = sizes.value()[groupRank];
}
else
{
outputShape[0] = outputShape[0] / mGroup.size();
}
auto output = torch::empty(outputShape, input.options());
if (use_nccl_reducescatter)
{
ncclReduceScatter(input.data_ptr(), output.mutable_data_ptr(), output.numel(), (*getDtypeMap())[type],
ncclSum, *mNcclComm, stream);
}
else
{
size_t numel_base
= std::accumulate(outputShape.cbegin() + 1, outputShape.cend(), 1, std::multiplies<>{});
int64_t split_offset = 0;
for (int root = 0; root < static_cast<int>(mGroup.size()); ++root)
{
auto split_size = sizes.value()[root];
ncclReduce(input.index({torch::indexing::Slice(split_offset, torch::indexing::None)}).data_ptr(),
output.mutable_data_ptr(), numel_base * split_size, (*getDtypeMap())[type], ncclSum, root,
*mNcclComm, stream);
split_offset += split_size;
}
}
output_list.push_back(output);
}
NCCLCHECK_THROW(ncclGroupEnd());
return output_list;
}
torch::Tensor run(torch::Tensor const& input, torch::optional<torch::List<int64_t>> sizes)
{
return run_list({input}, sizes)[0];
}
private:
std::set<int> mGroup;
std::shared_ptr<ncclComm_t> mNcclComm;
};
class ReducescatterPgOp
{
public:
ReducescatterPgOp(std::set<int> group, c10::intrusive_ptr<c10d::ProcessGroup> const& process_group_)
: mGroup(std::move(group))
, mProcessGroup(process_group_)
{
}
~ReducescatterPgOp() = default;
int initialize() noexcept
{
TLLM_LOG_TRACE("%s start for rank %d", __PRETTY_FUNCTION__, mProcessGroup->getRank());
return 0;
}
std::pair<torch::Tensor, c10::intrusive_ptr<c10d::Work>> run(
torch::Tensor input, torch::optional<torch::List<int64_t>> sizes, bool coalescing = false)
{
TLLM_CHECK_WITH_INFO(mProcessGroup.get() != nullptr, "mProcessGroup should be initialized before used");
auto rank = mProcessGroup->getRank();
std::vector<int64_t> outputShape = input.sizes().vec();
if (sizes.has_value())
{
TLLM_CHECK(sizes.value().size() == mGroup.size());
outputShape[0] = sizes.value()[rank];
}
else
{
outputShape[0] = outputShape[0] / mGroup.size();
}
auto output = torch::empty(outputShape, input.options());
int64_t split_offset = 0;
std::vector<torch::Tensor> inputTensors{};
for (int root = 0; root < static_cast<int>(mGroup.size()); ++root)
{
auto split_size = sizes.has_value() ? sizes.value()[root] : outputShape[0];
inputTensors.push_back(input.index({torch::indexing::Slice(split_offset, split_offset + split_size)}));
split_offset += split_size;
}
std::vector<torch::Tensor> outputs{output};
std::vector<std::vector<torch::Tensor>> inputs{inputTensors};
auto work = mProcessGroup->reduce_scatter(outputs, inputs, {});
if (!coalescing)
{
PGCHECK_THROW_WITH_INFO(work, "ProcessGroup: reduce_scatter");
return {output, nullptr};
}
return {output, work};
}
std::vector<torch::Tensor> run_list(torch::TensorList input_list, torch::optional<torch::List<int64_t>> sizes)
{
std::vector<torch::Tensor> output_list;
std::vector<c10::intrusive_ptr<c10d::Work>> work_list;
output_list.reserve(input_list.size());
work_list.reserve(input_list.size());
mProcessGroup->startCoalescing(c10::DeviceType::CUDA);
for (auto const& input : input_list)
{
auto [output, work] = run(input, sizes, true);
output_list.push_back(output);
work_list.push_back(work); // Hold work objects (input & output tensors) until endCoalescing wait finished
}
if (auto work = mProcessGroup->endCoalescing(c10::DeviceType::CUDA))
{
PGCHECK_THROW_WITH_INFO(work, "ProcessGroup: reduce_scatter, end coalescing");
}
return output_list;
}
private:
std::set<int> mGroup;
c10::intrusive_ptr<c10d::ProcessGroup> mProcessGroup;
};
} // namespace
#endif // ENABLE_MULTI_DEVICE
extern torch::Tensor reducescatter(
torch::Tensor input, torch::optional<torch::List<int64_t>> sizes, torch::List<int64_t> group_)
{
#if ENABLE_MULTI_DEVICE
std::set<int> group;
for (int64_t rank : group_)
{
group.insert(static_cast<int>(rank));
}
ReducescatterOp op(group);
op.initialize();
auto output = op.run(input, sizes);
return output;
#else
return input;
#endif // ENABLE_MULTI_DEVICE
}
extern torch::Tensor reducescatter_pg(torch::Tensor input, torch::optional<torch::List<int64_t>> sizes,
torch::List<int64_t> group_, c10::intrusive_ptr<c10d::ProcessGroup> const& process_group_)
{
#if ENABLE_MULTI_DEVICE
std::set<int> group;
for (int64_t rank : group_)
{
group.insert(static_cast<int>(rank));
}
ReducescatterPgOp op(group, process_group_);
op.initialize();
auto [output, _] = op.run(input, sizes);
return output;
#else
return input;
#endif // ENABLE_MULTI_DEVICE
}
extern std::vector<torch::Tensor> reducescatter_list(
torch::TensorList input_list, torch::optional<torch::List<int64_t>> sizes, torch::List<int64_t> group_)
{
#if ENABLE_MULTI_DEVICE
std::set<int> group;
for (int64_t rank : group_)
{
group.insert(static_cast<int>(rank));
}
ReducescatterOp op(group);
op.initialize();
auto output_list = op.run_list(input_list, sizes);
return output_list;
#else
return input_list.vec();
#endif // ENABLE_MULTI_DEVICE
}
extern std::vector<torch::Tensor> reducescatter_list_pg(torch::TensorList input_list,
torch::optional<torch::List<int64_t>> sizes, torch::List<int64_t> group_,
c10::intrusive_ptr<c10d::ProcessGroup> const& process_group_)
{
#if ENABLE_MULTI_DEVICE
std::set<int> group;
for (int64_t rank : group_)
{
group.insert(static_cast<int>(rank));
}
ReducescatterPgOp op(group, process_group_);
op.initialize();
auto output_list = op.run_list(input_list, sizes);
return output_list;
#else
return input_list.vec();
#endif // ENABLE_MULTI_DEVICE
}
} // namespace torch_ext
TRTLLM_NAMESPACE_END
TORCH_LIBRARY_FRAGMENT(trtllm, m)
{
m.def("reducescatter(Tensor input, SymInt[]? sizes, int[] group) -> Tensor");
m.def(
"reducescatter_pg(Tensor input, SymInt[]? sizes, int[] group, __torch__.torch.classes.c10d.ProcessGroup "
"process_group) -> Tensor");
m.def("reducescatter_list(Tensor[] input_list, SymInt[]? sizes, int[] group) -> Tensor[]");
m.def(
"reducescatter_list_pg(Tensor[] input_list, SymInt[]? sizes, int[] group, "
"__torch__.torch.classes.c10d.ProcessGroup process_group) -> Tensor[]");
}
TORCH_LIBRARY_IMPL(trtllm, CUDA, m)
{
m.impl("reducescatter", &tensorrt_llm::torch_ext::reducescatter);
m.impl("reducescatter_pg", &tensorrt_llm::torch_ext::reducescatter_pg);
m.impl("reducescatter_list", &tensorrt_llm::torch_ext::reducescatter_list);
m.impl("reducescatter_list_pg", &tensorrt_llm::torch_ext::reducescatter_list_pg);
}