fmoe_cuda.cpp

#include <iostream>
#include <vector>
#include <torch/extension.h>

// global_exchange
#ifdef FMOE_USE_NCCL
#include <c10d/ProcessGroupNCCL.hpp>
std::vector<torch::Tensor> _expert_exchange(
        torch::Tensor local_expert_count,
        long n_expert, long n_workers);
std::vector<torch::Tensor> _global_scatter(
        torch::Tensor input_buf,
        torch::Tensor local_expert_count,
        torch::Tensor global_expert_count,
        long batch_size, long n_workers);
std::vector<torch::Tensor> _global_gather(
        torch::Tensor output_buf,
        torch::Tensor local_expert_count,
        torch::Tensor global_expert_count,
        long batch_size, long n_workers);
void _ensure_nccl(c10d::ProcessGroupNCCL& p, torch::Tensor t);
#endif  // FMOE_USE_NCCL

// local_exchange
std::vector<torch::Tensor> _local_scatter(
    torch::Tensor input,
    torch::Tensor pos);
std::vector<torch::Tensor> _local_gather(
    torch::Tensor output_buf,
    torch::Tensor pos);
void _assign_pos(
    torch::Tensor cum_count,
    torch::Tensor gate,
    torch::Tensor pos);

// parallel_linear
std::vector<torch::Tensor> _linear_forward(
        torch::Tensor input_buf,
        torch::Tensor weight,
        torch::Tensor expert_count);
std::vector<torch::Tensor> _linear_backward(
    torch::Tensor grad_output_buf,
    torch::Tensor input_buf,
    torch::Tensor weight, 
    torch::Tensor expert_count);

// balancing
std::vector<torch::Tensor> _limit_by_capacity(
        torch::Tensor expert_count, torch::Tensor capacity,
        long n_expert, long n_experts);
void _prune_gate_by_capacity(
        torch::Tensor gate_idx, torch::Tensor expert_count,
        long n_expert, long n_worker);

PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
#ifdef FMOE_USE_NCCL
    m.def("expert_exchange", &_expert_exchange, "FastMoE expert exchange (CUDA)");
    m.def("global_scatter", &_global_scatter, "FastMoE global scatter (CUDA)");
    m.def("global_gather", &_global_gather, "FastMoE global gather (CUDA)");
    m.def("ensure_nccl", &_ensure_nccl, "FastMoE ensure torch nccl comm");
#endif

    m.def("local_scatter", &_local_scatter, "FastMoE local scatter (CUDA)");
    m.def("local_gather", &_local_gather, "FastMoE local gather (CUDA)");
    m.def("assign_pos_", &_assign_pos, "FastMoE assign pos by gate(CUDA)");

    m.def("linear_forward", &_linear_forward, "FastMoE forward (CUDA)");
    m.def("linear_backward", &_linear_backward, "FastMoE backward (CUDA)");

    m.def("limit_by_capacity", &_limit_by_capacity, "FastMoE limit experts by capacity(CUDA)");
    m.def("prune_gate_by_capacity", &_prune_gate_by_capacity, "FastMoE prune gate by capacity(CUDA)");
}