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vllm/csrc/moe/dsv3_router_gemm_entry.cu
2026-02-23 17:11:27 -08:00

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/*
* Adapted from SGLang's sgl-kernel implementation, which was adapted from
* https://github.com/NVIDIA/TensorRT-LLM/blob/main/cpp/tensorrt_llm/kernels/dsv3MinLatencyKernels/dsv3RouterGemm.cu
* https://github.com/NVIDIA/TensorRT-LLM/blob/main/cpp/tensorrt_llm/thop/dsv3RouterGemmOp.cpp
*
* Copyright (c) 2019-2023, NVIDIA CORPORATION. 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 <ATen/ATen.h>
#include <ATen/cuda/CUDAContext.h>
#include <torch/all.h>
#include <cuda_bf16.h>
#include <cuda_runtime.h>
#include "core/registration.h"
#include "dsv3_router_gemm_utils.h"
static constexpr int DEFAULT_NUM_EXPERTS = 256;
static constexpr int KIMI_K2_NUM_EXPERTS = 384;
static constexpr int DEFAULT_HIDDEN_DIM = 7168;
template <typename T, int kNumTokens, int kNumExperts, int kHiddenDim>
void invokeRouterGemmFloatOutput(float* output, T const* mat_a, T const* mat_b,
cudaStream_t stream);
template <typename T, int kNumTokens, int kNumExperts, int kHiddenDim>
void invokeRouterGemmBf16Output(__nv_bfloat16* output, T const* mat_a,
T const* mat_b, cudaStream_t stream);
template <int kBegin, int kEnd, int kNumExperts, int kHiddenDim>
struct LoopUnroller {
static void unroll_float_output(int num_tokens, float* output,
__nv_bfloat16 const* input,
__nv_bfloat16 const* weights,
cudaStream_t stream) {
if (num_tokens == kBegin) {
invokeRouterGemmFloatOutput<__nv_bfloat16, kBegin, kNumExperts,
kHiddenDim>(output, input, weights, stream);
} else {
LoopUnroller<kBegin + 1, kEnd, kNumExperts,
kHiddenDim>::unroll_float_output(num_tokens, output, input,
weights, stream);
}
}
static void unroll_bf16_output(int num_tokens, __nv_bfloat16* output,
__nv_bfloat16 const* input,
__nv_bfloat16 const* weights,
cudaStream_t stream) {
if (num_tokens == kBegin) {
invokeRouterGemmBf16Output<__nv_bfloat16, kBegin, kNumExperts,
kHiddenDim>(output, input, weights, stream);
} else {
LoopUnroller<kBegin + 1, kEnd, kNumExperts,
kHiddenDim>::unroll_bf16_output(num_tokens, output, input,
weights, stream);
}
}
};
template <int kEnd, int kNumExperts, int kHiddenDim>
struct LoopUnroller<kEnd, kEnd, kNumExperts, kHiddenDim> {
static void unroll_float_output(int num_tokens, float* output,
__nv_bfloat16 const* input,
__nv_bfloat16 const* weights,
cudaStream_t stream) {
if (num_tokens == kEnd) {
invokeRouterGemmFloatOutput<__nv_bfloat16, kEnd, kNumExperts, kHiddenDim>(
output, input, weights, stream);
} else {
throw std::invalid_argument("Invalid num_tokens, only supports 1 to 16");
}
}
static void unroll_bf16_output(int num_tokens, __nv_bfloat16* output,
__nv_bfloat16 const* input,
__nv_bfloat16 const* weights,
cudaStream_t stream) {
if (num_tokens == kEnd) {
invokeRouterGemmBf16Output<__nv_bfloat16, kEnd, kNumExperts, kHiddenDim>(
output, input, weights, stream);
} else {
throw std::invalid_argument("Invalid num_tokens, only supports 1 to 16");
}
}
};
void dsv3_router_gemm(at::Tensor& output, // [num_tokens, num_experts]
const at::Tensor& mat_a, // [num_tokens, hidden_dim]
const at::Tensor& mat_b // [num_experts, hidden_dim]
) {
TORCH_CHECK(output.dim() == 2 && mat_a.dim() == 2 && mat_b.dim() == 2);
const int num_tokens = mat_a.size(0);
const int num_experts = mat_b.size(0);
const int hidden_dim = mat_a.size(1);
TORCH_CHECK(mat_a.size(1) == mat_b.size(1),
"mat_a and mat_b must have the same hidden_dim");
TORCH_CHECK(hidden_dim == DEFAULT_HIDDEN_DIM,
"Expected hidden_dim=", DEFAULT_HIDDEN_DIM,
", but got hidden_dim=", hidden_dim);
TORCH_CHECK(
num_experts == DEFAULT_NUM_EXPERTS || num_experts == KIMI_K2_NUM_EXPERTS,
"Expected num_experts=", DEFAULT_NUM_EXPERTS,
" or num_experts=", KIMI_K2_NUM_EXPERTS,
", but got num_experts=", num_experts);
TORCH_CHECK(num_tokens >= 1 && num_tokens <= 16,
"currently num_tokens must be less than or equal to 16 for "
"router_gemm");
TORCH_CHECK(mat_a.dtype() == at::kBFloat16, "mat_a must be bf16");
TORCH_CHECK(mat_b.dtype() == at::kBFloat16, "mat_b must be bf16");
TORCH_CHECK(output.dtype() == at::kFloat || output.dtype() == at::kBFloat16,
"output must be float32 or bf16");
auto const sm = getSMVersion();
TORCH_CHECK(sm >= 90 && sm <= 103, "required SM_103 >= CUDA ARCH >= SM_90");
const cudaStream_t stream = at::cuda::getCurrentCUDAStream();
if (output.dtype() == at::kFloat) {
if (num_experts == DEFAULT_NUM_EXPERTS) {
LoopUnroller<1, 16, DEFAULT_NUM_EXPERTS, DEFAULT_HIDDEN_DIM>::
unroll_float_output(
num_tokens, reinterpret_cast<float*>(output.mutable_data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_a.data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_b.data_ptr()), stream);
} else if (num_experts == KIMI_K2_NUM_EXPERTS) {
LoopUnroller<1, 16, KIMI_K2_NUM_EXPERTS, DEFAULT_HIDDEN_DIM>::
unroll_float_output(
num_tokens, reinterpret_cast<float*>(output.mutable_data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_a.data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_b.data_ptr()), stream);
}
} else if (output.dtype() == at::kBFloat16) {
if (num_experts == DEFAULT_NUM_EXPERTS) {
LoopUnroller<1, 16, DEFAULT_NUM_EXPERTS, DEFAULT_HIDDEN_DIM>::
unroll_bf16_output(
num_tokens,
reinterpret_cast<__nv_bfloat16*>(output.mutable_data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_a.data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_b.data_ptr()), stream);
} else if (num_experts == KIMI_K2_NUM_EXPERTS) {
LoopUnroller<1, 16, KIMI_K2_NUM_EXPERTS, DEFAULT_HIDDEN_DIM>::
unroll_bf16_output(
num_tokens,
reinterpret_cast<__nv_bfloat16*>(output.mutable_data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_a.data_ptr()),
reinterpret_cast<__nv_bfloat16 const*>(mat_b.data_ptr()), stream);
}
}
}
TORCH_LIBRARY_IMPL_EXPAND(TORCH_EXTENSION_NAME, CUDA, m) {
m.impl("dsv3_router_gemm", &dsv3_router_gemm);
}