xgboost/src/collective/device_communicator_adapter.cuh

130 lines
4.3 KiB
Plaintext

/*!
* Copyright 2022 XGBoost contributors
*/
#pragma once
#include "communicator.h"
#include "device_communicator.cuh"
namespace xgboost {
namespace collective {
class DeviceCommunicatorAdapter : public DeviceCommunicator {
public:
DeviceCommunicatorAdapter(int device_ordinal, Communicator *communicator)
: device_ordinal_{device_ordinal}, communicator_{communicator} {
if (device_ordinal_ < 0) {
LOG(FATAL) << "Invalid device ordinal: " << device_ordinal_;
}
if (communicator_ == nullptr) {
LOG(FATAL) << "Communicator cannot be null.";
}
}
~DeviceCommunicatorAdapter() override = default;
void AllReduceSum(float *send_receive_buffer, size_t count) override {
DoAllReduceSum<collective::DataType::kFloat>(send_receive_buffer, count);
}
void AllReduceSum(double *send_receive_buffer, size_t count) override {
DoAllReduceSum<collective::DataType::kDouble>(send_receive_buffer, count);
}
void AllReduceSum(int64_t *send_receive_buffer, size_t count) override {
DoAllReduceSum<collective::DataType::kInt64>(send_receive_buffer, count);
}
void AllReduceSum(uint64_t *send_receive_buffer, size_t count) override {
DoAllReduceSum<collective::DataType::kUInt64>(send_receive_buffer, count);
}
void AllGatherV(void const *send_buffer, size_t length_bytes, std::vector<std::size_t> *segments,
dh::caching_device_vector<char> *receive_buffer) override {
if (communicator_->GetWorldSize() == 1) {
return;
}
#if defined(XGBOOST_USE_HIP)
dh::safe_cuda(hipSetDevice(device_ordinal_));
#else
dh::safe_cuda(cudaSetDevice(device_ordinal_));
#endif
int const world_size = communicator_->GetWorldSize();
int const rank = communicator_->GetRank();
segments->clear();
segments->resize(world_size, 0);
segments->at(rank) = length_bytes;
communicator_->AllReduce(segments->data(), segments->size(), DataType::kUInt64,
Operation::kMax);
auto total_bytes = std::accumulate(segments->cbegin(), segments->cend(), 0UL);
receive_buffer->resize(total_bytes);
host_buffer_.reserve(total_bytes);
size_t offset = 0;
for (int32_t i = 0; i < world_size; ++i) {
size_t as_bytes = segments->at(i);
if (i == rank) {
#if defined(XGBOOST_USE_HIP)
dh::safe_cuda(hipMemcpy(host_buffer_.data() + offset, send_buffer, segments->at(rank),
hipMemcpyDefault));
#else
dh::safe_cuda(cudaMemcpy(host_buffer_.data() + offset, send_buffer, segments->at(rank),
cudaMemcpyDefault));
#endif
}
communicator_->Broadcast(host_buffer_.data() + offset, as_bytes, i);
offset += as_bytes;
}
#if defined(XGBOOST_USE_HIP)
dh::safe_cuda(hipMemcpy(receive_buffer->data().get(), host_buffer_.data(), total_bytes,
hipMemcpyDefault));
#else
dh::safe_cuda(cudaMemcpy(receive_buffer->data().get(), host_buffer_.data(), total_bytes,
cudaMemcpyDefault));
#endif
}
void Synchronize() override {
// Noop.
}
private:
template <collective::DataType data_type, typename T>
void DoAllReduceSum(T *send_receive_buffer, size_t count) {
if (communicator_->GetWorldSize() == 1) {
return;
}
#if defined(XGBOOST_USE_HIP)
dh::safe_cuda(hipSetDevice(device_ordinal_));
#else
dh::safe_cuda(cudaSetDevice(device_ordinal_));
#endif
auto size = count * sizeof(T);
host_buffer_.reserve(size);
#if defined(XGBOOST_USE_HIP)
dh::safe_cuda(hipMemcpy(host_buffer_.data(), send_receive_buffer, size, hipMemcpyDefault));
communicator_->AllReduce(host_buffer_.data(), count, data_type, collective::Operation::kSum);
dh::safe_cuda(hipMemcpy(send_receive_buffer, host_buffer_.data(), size, hipMemcpyDefault));
#else
dh::safe_cuda(cudaMemcpy(host_buffer_.data(), send_receive_buffer, size, cudaMemcpyDefault));
communicator_->AllReduce(host_buffer_.data(), count, data_type, collective::Operation::kSum);
dh::safe_cuda(cudaMemcpy(send_receive_buffer, host_buffer_.data(), size, cudaMemcpyDefault));
#endif
}
int const device_ordinal_;
Communicator *communicator_;
/// Host buffer used to call communicator functions.
std::vector<char> host_buffer_{};
};
} // namespace collective
} // namespace xgboost