permute/unpermute kernel for moe optimization (#14568)

Signed-off-by: Caleb_Du <Caleb_Du@zju.edu.cn>
This commit is contained in:
Caleb_Du
2025-05-03 02:31:55 +08:00
committed by GitHub
parent 0f87d8f7b2
commit 3e887d2e0c
19 changed files with 1474 additions and 28 deletions

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#include <c10/core/ScalarType.h>
#include <torch/all.h>
#include <ATen/cuda/CUDAContext.h>
#include "permute_unpermute_kernels/moe_permute_unpermute_kernel.h"
#include "permute_unpermute_kernels/dispatch.h"
#include "core/registration.h"
void moe_permute(
const torch::Tensor& input, // [n_token, hidden]
const torch::Tensor& topk_weights, //[n_token, topk]
torch::Tensor& topk_ids, // [n_token, topk]
const torch::Tensor& token_expert_indicies, // [n_token, topk]
const std::optional<torch::Tensor>& expert_map, // [n_expert]
int64_t n_expert, int64_t n_local_expert, int64_t topk,
const std::optional<int64_t>& align_block_size,
torch::Tensor&
permuted_input, // [topk * n_token/align_block_size_m, hidden]
torch::Tensor& expert_first_token_offset, // [n_local_expert + 1]
torch::Tensor& src_row_id2dst_row_id_map, // [n_token, topk]
torch::Tensor& m_indices) { // [align_expand_m]
TORCH_CHECK(topk_weights.scalar_type() == at::ScalarType::Float,
"topk_weights must be float32");
TORCH_CHECK(expert_first_token_offset.scalar_type() == at::ScalarType::Long,
"expert_first_token_offset must be int64");
TORCH_CHECK(topk_ids.scalar_type() == at::ScalarType::Int,
"topk_ids must be int32");
TORCH_CHECK(token_expert_indicies.scalar_type() == at::ScalarType::Int,
"token_expert_indicies must be int32");
TORCH_CHECK(src_row_id2dst_row_id_map.scalar_type() == at::ScalarType::Int,
"src_row_id2dst_row_id_map must be int32");
TORCH_CHECK(expert_first_token_offset.size(0) == n_local_expert + 1,
"expert_first_token_offset shape != n_local_expert+1")
TORCH_CHECK(
src_row_id2dst_row_id_map.sizes() == token_expert_indicies.sizes(),
"token_expert_indicies shape must be same as src_row_id2dst_row_id_map");
auto n_token = input.sizes()[0];
auto n_hidden = input.sizes()[1];
auto align_block_size_value =
align_block_size.has_value() ? align_block_size.value() : -1;
auto stream = at::cuda::getCurrentCUDAStream().stream();
const long sorter_size =
CubKeyValueSorter::getWorkspaceSize(n_token * topk, n_expert);
auto sort_workspace = torch::empty(
{sorter_size},
torch::dtype(torch::kInt8).device(torch::kCUDA).requires_grad(false));
auto permuted_experts_id = torch::empty_like(topk_ids);
auto dst_row_id2src_row_id_map = torch::empty_like(src_row_id2dst_row_id_map);
auto align_expert_first_token_offset =
torch::zeros_like(expert_first_token_offset);
CubKeyValueSorter sorter{};
int64_t* valid_num_ptr = nullptr;
// pre-process kernel for expert-parallelism:
// no local expert id plus "n_expert" offset for priority to local expert
// map local expert id [n, .., n+n_local_expert-1] to [0, n_local_expert -1]
// For example, 4 expert with ep_size=2. ep_rank=1 owns global expert id
// [2,3] with expert_map[-1, -1, 0, 1], preprocess_topk_id process topk_ids
// and map global expert id [2, 3] to local_expert id [0, 1] and map global
// expert id [0, 1] ( not in ep rank=1) to [4, 5] by plus n_expert. This map
// operation is to make local expert high priority in following sort topk_ids
// and scan local expert_first_token_offset for each ep rank for next group
// gemm.
if (expert_map.has_value()) {
const int* expert_map_ptr = get_ptr<int>(expert_map.value());
valid_num_ptr =
get_ptr<int64_t>(expert_first_token_offset) + n_local_expert;
preprocessTopkIdLauncher(get_ptr<int>(topk_ids), n_token * topk,
expert_map_ptr, n_expert, stream);
}
// expert sort topk expert id and scan expert id get expert_first_token_offset
sortAndScanExpert(get_ptr<int>(topk_ids), get_ptr<int>(token_expert_indicies),
get_ptr<int>(permuted_experts_id),
get_ptr<int>(dst_row_id2src_row_id_map),
get_ptr<int64_t>(expert_first_token_offset), n_token,
n_expert, n_local_expert, topk, sorter,
get_ptr<int>(sort_workspace), stream);
// dispatch expandInputRowsKernelLauncher
MOE_DISPATCH(input.scalar_type(), [&] {
expandInputRowsKernelLauncher<scalar_t>(
get_ptr<scalar_t>(input), get_ptr<scalar_t>(permuted_input),
get_ptr<float>(topk_weights), get_ptr<int>(permuted_experts_id),
get_ptr<int>(dst_row_id2src_row_id_map),
get_ptr<int>(src_row_id2dst_row_id_map),
get_ptr<int64_t>(expert_first_token_offset), n_token, valid_num_ptr,
n_hidden, topk, n_local_expert, align_block_size_value, stream);
});
// get m_indices and update expert_first_token_offset with align block
getMIndices(get_ptr<int64_t>(expert_first_token_offset),
get_ptr<int64_t>(align_expert_first_token_offset),
get_ptr<int>(m_indices), n_local_expert, align_block_size_value,
stream);
if (align_block_size.has_value()) {
// update align_expert_first_token_offset
expert_first_token_offset.copy_(align_expert_first_token_offset);
}
}
void moe_unpermute(
const torch::Tensor& permuted_hidden_states, // [n_token * topk, hidden]
const torch::Tensor& topk_weights, //[n_token, topk]
const torch::Tensor& topk_ids, // [n_token, topk]
const torch::Tensor& src_row_id2dst_row_id_map, // [n_token, topk]
const torch::Tensor& expert_first_token_offset, // [n_local_expert+1]
int64_t n_expert, int64_t n_local_expert, int64_t topk,
torch::Tensor& hidden_states // [n_token, hidden]
) {
TORCH_CHECK(src_row_id2dst_row_id_map.sizes() == topk_ids.sizes(),
"topk_ids shape must be same as src_row_id2dst_row_id_map");
TORCH_CHECK(topk_ids.scalar_type() == at::ScalarType::Int,
"topk_ids must be int32");
TORCH_CHECK(
permuted_hidden_states.scalar_type() == hidden_states.scalar_type(),
"topk_ids dtype must be same as src_row_id2dst_row_id_map");
auto n_token = hidden_states.size(0);
auto n_hidden = hidden_states.size(1);
auto stream = at::cuda::getCurrentCUDAStream().stream();
const int64_t* valid_ptr =
get_ptr<int64_t>(expert_first_token_offset) + n_local_expert;
MOE_DISPATCH(hidden_states.scalar_type(), [&] {
finalizeMoeRoutingKernelLauncher<scalar_t, scalar_t>(
get_ptr<scalar_t>(permuted_hidden_states),
get_ptr<scalar_t>(hidden_states), get_ptr<float>(topk_weights),
get_ptr<int>(src_row_id2dst_row_id_map), get_ptr<int>(topk_ids),
n_token, n_hidden, topk, valid_ptr, stream);
});
}
TORCH_LIBRARY_IMPL_EXPAND(TORCH_EXTENSION_NAME, CUDA, m) {
m.impl("moe_permute", &moe_permute);
m.impl("moe_unpermute", &moe_unpermute);
}

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#pragma once
#include <cuda_fp8.h>
#define MOE_SWITCH(TYPE, ...) \
at::ScalarType _st = ::detail::scalar_type(TYPE); \
switch (_st) { \
__VA_ARGS__ \
default: \
TORCH_CHECK(false, "[moe permute]data type dispatch fail!") \
}
#define MOE_DISPATCH_CASE(enum_type, ...) \
case enum_type: { \
using scalar_t = ScalarType2CudaType<enum_type>::type; \
__VA_ARGS__(); \
break; \
}
#define MOE_DISPATCH_FLOAT_CASE(...) \
MOE_DISPATCH_CASE(at::ScalarType::Float, __VA_ARGS__) \
MOE_DISPATCH_CASE(at::ScalarType::Half, __VA_ARGS__) \
MOE_DISPATCH_CASE(at::ScalarType::BFloat16, __VA_ARGS__) \
MOE_DISPATCH_CASE(at::ScalarType::Float8_e5m2, __VA_ARGS__) \
MOE_DISPATCH_CASE(at::ScalarType::Float8_e4m3fn, __VA_ARGS__)
#define MOE_DISPATCH(TYPE, ...) \
MOE_SWITCH(TYPE, MOE_DISPATCH_FLOAT_CASE(__VA_ARGS__))
template <at::ScalarType type>
struct ScalarType2CudaType;
template <>
struct ScalarType2CudaType<at::ScalarType::Float> {
using type = float;
};
template <>
struct ScalarType2CudaType<at::ScalarType::Half> {
using type = half;
};
template <>
struct ScalarType2CudaType<at::ScalarType::BFloat16> {
using type = __nv_bfloat16;
};
// #if __CUDA_ARCH__ >= 890
// fp8
template <>
struct ScalarType2CudaType<at::ScalarType::Float8_e5m2> {
using type = __nv_fp8_e5m2;
};
template <>
struct ScalarType2CudaType<at::ScalarType::Float8_e4m3fn> {
using type = __nv_fp8_e4m3;
};
// #endif

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#include "moe_permute_unpermute_kernel.h"
// CubKeyValueSorter definition begin
CubKeyValueSorter::CubKeyValueSorter()
: num_experts_(0), num_bits_(sizeof(int) * 8) {}
int CubKeyValueSorter::expertsToBits(int num_experts) {
// Max value we represent is V = num_experts + (num_experts - 1) = 2 *
// num_experts - 1 The maximum number of bits is therefore floor(log2(V)) + 1
return static_cast<int>(log2(2 * num_experts - 1)) + 1;
}
CubKeyValueSorter::CubKeyValueSorter(int const num_experts)
: num_experts_(num_experts), num_bits_(expertsToBits(num_experts)) {}
void CubKeyValueSorter::updateNumExperts(int const num_experts) {
num_experts_ = num_experts;
num_bits_ = expertsToBits(num_experts);
}
size_t CubKeyValueSorter::getWorkspaceSize(size_t const num_key_value_pairs,
int const num_experts) {
int num_bits = expertsToBits(num_experts);
size_t required_storage = 0;
int* null_int = nullptr;
cub::DeviceRadixSort::SortPairs(nullptr, required_storage, null_int, null_int,
null_int, null_int, num_key_value_pairs, 0,
num_bits);
// when num_key_value_pairs, num_experts, num_bits, required_storage = 64,
// 4, 3, 0 The required_storage seems to vary between 0 and 1 for the same
// inputs
if (required_storage == 0) {
required_storage = 1;
}
return required_storage;
}
void CubKeyValueSorter::run(void* workspace, size_t const workspace_size,
int const* keys_in, int* keys_out,
int const* values_in, int* values_out,
size_t const num_key_value_pairs,
cudaStream_t stream) {
size_t expected_ws_size = getWorkspaceSize(num_key_value_pairs, num_experts_);
size_t actual_ws_size = workspace_size;
TORCH_CHECK(expected_ws_size <= workspace_size,
"[CubKeyValueSorter::run] The allocated workspace is too small "
"to run this problem.");
cub::DeviceRadixSort::SortPairs(workspace, actual_ws_size, keys_in, keys_out,
values_in, values_out, num_key_value_pairs, 0,
num_bits_, stream);
}
// CubKeyValueSorter definition end
static inline size_t pad_to_multiple_of_16(size_t const& input) {
static constexpr int ALIGNMENT = 16;
return ALIGNMENT * ((input + ALIGNMENT - 1) / ALIGNMENT);
}
template <class T>
__device__ inline int64_t findTotalEltsLessThanTarget(T const* sorted_indices,
int64_t const arr_length,
T const target) {
int64_t low = 0, high = arr_length - 1, target_location = -1;
while (low <= high) {
int64_t mid = (low + high) / 2;
if (sorted_indices[mid] >= target) {
high = mid - 1;
} else {
low = mid + 1;
target_location = mid;
}
}
return target_location + 1;
}
// Calculates the start offset of the tokens for a given expert. The last
// element is the total number of valid tokens
__global__ void computeExpertFirstTokenOffsetKernel(
int const* sorted_experts, int64_t const sorted_experts_len,
int const num_experts, int64_t* expert_first_token_offset) {
// First, compute the global tid. We only need 1 thread per expert.
int const expert = blockIdx.x * blockDim.x + threadIdx.x;
// Note that expert goes [0, num_experts] (inclusive) because we want a count
// for the total number of active tokens at the end of the scan.
if (expert >= num_experts + 1) {
return;
}
expert_first_token_offset[expert] =
findTotalEltsLessThanTarget(sorted_experts, sorted_experts_len, expert);
}
void computeExpertFirstTokenOffset(int const* sorted_indices,
int const total_indices,
int const num_experts,
int64_t* expert_first_token_offset,
cudaStream_t stream) {
int const num_entries = num_experts + 1;
int const threads = std::min(1024, num_entries);
int const blocks = (num_entries + threads - 1) / threads;
computeExpertFirstTokenOffsetKernel<<<blocks, threads, 0, stream>>>(
sorted_indices, total_indices, num_experts, expert_first_token_offset);
}
void sortAndScanExpert(int* expert_for_source_row, const int* source_rows,
int* permuted_experts, int* permuted_rows,
int64_t* expert_first_token_offset, int num_rows,
int num_experts, int num_experts_per_node, int k,
CubKeyValueSorter& sorter, void* sorter_ws,
cudaStream_t stream) {
int64_t const expanded_num_rows = static_cast<int64_t>(k) * num_rows;
// We need to use the full num_experts because that is the sentinel value used
// by topk for disabled experts
sorter.updateNumExperts(num_experts);
size_t const sorter_ws_size_bytes = pad_to_multiple_of_16(
sorter.getWorkspaceSize(expanded_num_rows, num_experts));
sorter.run((void*)sorter_ws, sorter_ws_size_bytes, expert_for_source_row,
permuted_experts, source_rows, permuted_rows, expanded_num_rows,
stream);
computeExpertFirstTokenOffset(permuted_experts, expanded_num_rows,
num_experts_per_node, expert_first_token_offset,
stream);
}
__global__ void preprocessTopkIdKernel(int* topk_id_ptr, int size,
const int* expert_map_ptr,
int num_experts) {
auto tidx = threadIdx.x;
auto bidx = blockIdx.x;
auto lidx = tidx & 31;
auto widx = tidx >> 5;
auto warp_count = (blockDim.x + 31) >> 5;
auto offset = bidx * blockDim.x;
auto bound = min(offset + blockDim.x, size);
extern __shared__ int smem_expert_map[];
// store expert_map in smem
for (int i = tidx; i < num_experts; i += blockDim.x) {
smem_expert_map[i] = expert_map_ptr[i];
}
__syncthreads();
// query global expert id in expert map.
// if global expert id = -1 in exert map, plus n_expert
// else set global expert id = exert map[global expert id]
if (offset + tidx < bound) {
auto topk_id = topk_id_ptr[offset + tidx];
auto local_expert_idx = smem_expert_map[topk_id];
if (local_expert_idx == -1) {
topk_id += num_experts;
} else {
topk_id = local_expert_idx;
}
__syncwarp();
topk_id_ptr[offset + tidx] = topk_id;
}
}
void preprocessTopkIdLauncher(int* topk_id_ptr, int size,
const int* expert_map_ptr, int num_experts,
cudaStream_t stream) {
int block = std::min(size, 1024);
int grid = (size + block - 1) / block;
int smem_size = (num_experts) * sizeof(int);
preprocessTopkIdKernel<<<grid, block, smem_size, stream>>>(
topk_id_ptr, size, expert_map_ptr, num_experts);
}
template <bool ALIGN_BLOCK_SIZE>
__global__ void getMIndicesKernel(int64_t* expert_first_token_offset,
int64_t* align_expert_first_token_offset,
int* m_indices, const int num_local_expert,
const int align_block_size) {
int eidx = blockIdx.x;
int tidx = threadIdx.x;
extern __shared__ int64_t smem_expert_first_token_offset[];
for (int i = tidx; i <= num_local_expert; i += blockDim.x) {
smem_expert_first_token_offset[tidx] = __ldg(expert_first_token_offset + i);
}
__syncthreads();
auto last_token_offset = smem_expert_first_token_offset[eidx + 1];
auto first_token_offset = smem_expert_first_token_offset[eidx];
int n_token_in_expert = last_token_offset - first_token_offset;
if constexpr (ALIGN_BLOCK_SIZE) {
n_token_in_expert = (n_token_in_expert + align_block_size - 1) /
align_block_size * align_block_size;
// round up to ALIGN_BLOCK_SIZE
int64_t accumulate_align_offset = 0;
for (int i = 1; i <= eidx + 1; i++) {
int n_token = smem_expert_first_token_offset[i] -
smem_expert_first_token_offset[i - 1];
accumulate_align_offset =
accumulate_align_offset + (n_token + align_block_size - 1) /
align_block_size * align_block_size;
if (i == eidx) {
first_token_offset = accumulate_align_offset;
}
// last block store align_expert_first_token_offset
if (eidx == num_local_expert - 1 && threadIdx.x == 0) {
align_expert_first_token_offset[i] = accumulate_align_offset;
}
}
}
for (int idx = tidx; idx < n_token_in_expert; idx += blockDim.x) {
// update m_indice with expert id
m_indices[first_token_offset + idx] = eidx;
}
}
void getMIndices(int64_t* expert_first_token_offset,
int64_t* align_expert_first_token_offset, int* m_indices,
int num_local_expert, const int align_block_size,
cudaStream_t stream) {
int block = 256;
int grid = num_local_expert;
int smem_size = sizeof(int64_t) * (num_local_expert + 1);
if (align_block_size == -1) {
getMIndicesKernel<false><<<grid, block, smem_size, stream>>>(
expert_first_token_offset, align_expert_first_token_offset, m_indices,
num_local_expert, align_block_size);
} else {
getMIndicesKernel<true><<<grid, block, smem_size, stream>>>(
expert_first_token_offset, align_expert_first_token_offset, m_indices,
num_local_expert, align_block_size);
}
}

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#pragma once
// reference from tensorrt_llm moe kernel implementation archive in
// https://github.com/BBuf/tensorrt-llm-moe/tree/master
#include <c10/core/ScalarType.h>
#include <torch/all.h>
#include "dispatch.h"
#include <cub/cub.cuh>
#include <cub/device/device_radix_sort.cuh>
#include <cub/util_type.cuh>
#include "cutlass/numeric_size.h"
#include "cutlass/array.h"
template <typename T>
inline T* get_ptr(torch::Tensor& t) {
return reinterpret_cast<T*>(t.data_ptr());
}
template <typename T>
inline const T* get_ptr(const torch::Tensor& t) {
return reinterpret_cast<const T*>(t.data_ptr());
}
class CubKeyValueSorter {
public:
CubKeyValueSorter();
CubKeyValueSorter(int const num_experts);
void updateNumExperts(int const num_experts);
static size_t getWorkspaceSize(size_t const num_key_value_pairs,
int const num_experts);
void run(void* workspace, size_t const workspace_size, int const* keys_in,
int* keys_out, int const* values_in, int* values_out,
size_t const num_key_value_pairs, cudaStream_t stream);
private:
static int expertsToBits(int experts);
int num_experts_;
int num_bits_;
};
void computeExpertFirstTokenOffset(int const* sorted_indices,
int const total_indices,
int const num_experts,
int64_t* expert_first_token_offset,
cudaStream_t stream);
void sortAndScanExpert(int* expert_for_source_row, const int* source_rows,
int* permuted_experts, int* permuted_rows,
int64_t* expert_first_token_offset, int num_rows,
int num_experts, int num_experts_per_node, int k,
CubKeyValueSorter& sorter, void* sorter_ws,
cudaStream_t stream);
template <typename T>
void expandInputRowsKernelLauncher(
T const* unpermuted_input, T* permuted_output,
const float* unpermuted_scales, int* sorted_experts,
int const* expanded_dest_row_to_expanded_source_row,
int* expanded_source_row_to_expanded_dest_row,
int64_t* expert_first_token_offset, int64_t const num_rows,
int64_t const* num_valid_tokens_ptr, int64_t const cols, int const k,
int num_local_experts, const int& align_block_size, cudaStream_t stream);
// Final kernel to unpermute and scale
// This kernel unpermutes the original data, does the k-way reduction and
// performs the final skip connection.
template <typename T, typename OutputType, bool CHECK_SKIPPED>
__global__ void finalizeMoeRoutingKernel(
T const* expanded_permuted_rows, OutputType* reduced_unpermuted_output,
float const* scales, int const* expanded_source_row_to_expanded_dest_row,
int const* expert_for_source_row, int64_t const orig_cols, int64_t const k,
int64_t const* num_valid_ptr);
template <class T, class OutputType>
void finalizeMoeRoutingKernelLauncher(
T const* expanded_permuted_rows, OutputType* reduced_unpermuted_output,
float const* scales, int const* expanded_source_row_to_expanded_dest_row,
int const* expert_for_source_row, int64_t const num_rows,
int64_t const cols, int64_t const k, int64_t const* num_valid_ptr,
cudaStream_t stream);
void preprocessTopkIdLauncher(int* topk_id_ptr, int size,
const int* expert_map_ptr, int num_experts,
cudaStream_t stream);
void getMIndices(int64_t* expert_first_token_offset,
int64_t* align_expert_first_token_offset, int* m_indices,
int num_local_expert, const int align_block_size,
cudaStream_t stream);
#include "moe_permute_unpermute_kernel.inl"

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#pragma once
template <typename T, bool CHECK_SKIPPED, bool ALIGN_BLOCK_SIZE>
__global__ void expandInputRowsKernel(
T const* unpermuted_input, T* permuted_output,
const float* unpermuted_scales, int* sorted_experts,
int const* expanded_dest_row_to_expanded_source_row,
int* expanded_source_row_to_expanded_dest_row,
int64_t* expert_first_token_offset, int64_t const num_rows,
int64_t const* num_dest_rows, int64_t const cols, int64_t k,
int num_local_experts, int align_block_size) {
// Reverse permutation map.
// I do this so that later, we can use the source -> dest map to do the k-way
// reduction and unpermuting. I need the reverse map for that reduction to
// allow each threadblock to do 1 k-way reduce without atomics later in MoE. 1
// thread block will be responsible for all k summations.
int64_t expanded_dest_row = blockIdx.x;
int64_t const expanded_source_row =
expanded_dest_row_to_expanded_source_row[expanded_dest_row];
int expert_id = sorted_experts[expanded_dest_row];
extern __shared__ int64_t smem_expert_first_token_offset[];
int64_t align_expanded_row_accumulate = 0;
if constexpr (ALIGN_BLOCK_SIZE) {
// load g2s
for (int idx = threadIdx.x; idx < num_local_experts + 1;
idx += blockDim.x) {
smem_expert_first_token_offset[idx] =
__ldg(expert_first_token_offset + idx);
}
__syncthreads();
int lane_idx = threadIdx.x & 31;
if (lane_idx == 0) {
// set token_offset_in_expert = 0 if this expert is not local expert
int token_offset_in_expert =
expert_id >= num_local_experts
? 0
: expanded_dest_row - smem_expert_first_token_offset[expert_id];
int64_t accumulate_align_offset = 0;
#pragma unroll 1
for (int eidx = 1; eidx <= min(expert_id, num_local_experts); eidx++) {
auto n_token_in_expert = smem_expert_first_token_offset[eidx] -
smem_expert_first_token_offset[eidx - 1];
accumulate_align_offset += (n_token_in_expert + align_block_size - 1) /
align_block_size * align_block_size;
}
expanded_dest_row = accumulate_align_offset + token_offset_in_expert;
}
// lane0 shuffle broadcast align_expanded_dest_row
expanded_dest_row = __shfl_sync(0xffffffff, expanded_dest_row, 0);
}
if (threadIdx.x == 0) {
assert(expanded_dest_row <= INT32_MAX);
expanded_source_row_to_expanded_dest_row[expanded_source_row] =
static_cast<int>(expanded_dest_row);
}
if (!CHECK_SKIPPED || blockIdx.x < *num_dest_rows) {
// Load 128-bits per thread
constexpr int64_t ELEM_PER_THREAD = 128 / cutlass::sizeof_bits<T>::value;
using DataElem = cutlass::Array<T, ELEM_PER_THREAD>;
// Duplicate and permute rows
int64_t const source_k_rank = expanded_source_row / num_rows;
int64_t const source_row = expanded_source_row % num_rows;
auto const* source_row_ptr =
reinterpret_cast<DataElem const*>(unpermuted_input + source_row * cols);
auto* dest_row_ptr =
reinterpret_cast<DataElem*>(permuted_output + expanded_dest_row * cols);
int64_t const start_offset = threadIdx.x;
int64_t const stride = blockDim.x;
int64_t const num_elems_in_col = cols / ELEM_PER_THREAD;
for (int elem_index = start_offset; elem_index < num_elems_in_col;
elem_index += stride) {
dest_row_ptr[elem_index] = source_row_ptr[elem_index];
}
}
}
template <typename T>
void expandInputRowsKernelLauncher(
T const* unpermuted_input, T* permuted_output,
const float* unpermuted_scales, int* sorted_experts,
int const* expanded_dest_row_to_expanded_source_row,
int* expanded_source_row_to_expanded_dest_row,
int64_t* expert_first_token_offset, int64_t const num_rows,
int64_t const* num_valid_tokens_ptr, int64_t const cols, int const k,
int num_local_experts, const int& align_block_size, cudaStream_t stream) {
int64_t const blocks = num_rows * k;
int64_t const threads = 256;
using FuncPtr = decltype(&expandInputRowsKernel<T, true, true>);
FuncPtr func_map[2][2] = {
{&expandInputRowsKernel<T, false, false>,
&expandInputRowsKernel<T, false, true>},
{&expandInputRowsKernel<T, true, false>,
&expandInputRowsKernel<T, true, true>},
};
bool is_check_skip = num_valid_tokens_ptr != nullptr;
bool is_align_block_size = align_block_size != -1;
auto func = func_map[is_check_skip][is_align_block_size];
int64_t smem_size = sizeof(int64_t) * (num_local_experts + 1);
func<<<blocks, threads, smem_size, stream>>>(
unpermuted_input, permuted_output, unpermuted_scales, sorted_experts,
expanded_dest_row_to_expanded_source_row,
expanded_source_row_to_expanded_dest_row, expert_first_token_offset,
num_rows, num_valid_tokens_ptr, cols, k, num_local_experts,
align_block_size);
}
template <class T, class U>
__host__ __device__ constexpr static U arrayConvert(T const& input) {
using Type = typename U::Element;
static_assert(T::kElements == U::kElements);
U u;
#pragma unroll
for (int i = 0; i < U::kElements; i++) {
u[i] = static_cast<Type>(input[i]);
}
return u;
}
template <typename T, typename OutputType, bool CHECK_SKIPPED>
__global__ void finalizeMoeRoutingKernel(
T const* expanded_permuted_rows, OutputType* reduced_unpermuted_output,
float const* scales, int const* expanded_source_row_to_expanded_dest_row,
int const* expert_for_source_row, int64_t const orig_cols, int64_t const k,
int64_t const* num_valid_ptr) {
assert(orig_cols % 4 == 0);
int64_t const original_row = blockIdx.x;
int64_t const num_rows = gridDim.x;
auto const offset = original_row * orig_cols;
OutputType* reduced_row_ptr = reduced_unpermuted_output + offset;
int64_t const num_valid = *num_valid_ptr;
// Load 128-bits per thread, according to the smallest data type we read/write
constexpr int64_t FINALIZE_ELEM_PER_THREAD =
128 / std::min(cutlass::sizeof_bits<OutputType>::value,
cutlass::sizeof_bits<T>::value);
int64_t const start_offset = threadIdx.x;
int64_t const stride = blockDim.x;
int64_t const num_elems_in_col = orig_cols / FINALIZE_ELEM_PER_THREAD;
using InputElem = cutlass::Array<T, FINALIZE_ELEM_PER_THREAD>;
using OutputElem = cutlass::Array<OutputType, FINALIZE_ELEM_PER_THREAD>;
using ComputeElem = cutlass::Array<float, FINALIZE_ELEM_PER_THREAD>;
auto const* expanded_permuted_rows_v =
reinterpret_cast<InputElem const*>(expanded_permuted_rows);
auto* reduced_row_ptr_v = reinterpret_cast<OutputElem*>(reduced_row_ptr);
#pragma unroll
for (int elem_index = start_offset; elem_index < num_elems_in_col;
elem_index += stride) {
ComputeElem thread_output;
thread_output.fill(0);
float row_rescale{0.f};
for (int k_idx = 0; k_idx < k; ++k_idx) {
int64_t const expanded_original_row = original_row + k_idx * num_rows;
int64_t const expanded_permuted_row =
expanded_source_row_to_expanded_dest_row[expanded_original_row];
int64_t const k_offset = original_row * k + k_idx;
float const row_scale = scales[k_offset];
// Check after row_rescale has accumulated
if (CHECK_SKIPPED && expanded_permuted_row >= num_valid) {
continue;
}
auto const* expanded_permuted_rows_row_ptr =
expanded_permuted_rows_v + expanded_permuted_row * num_elems_in_col;
int64_t const expert_idx = expert_for_source_row[k_offset];
ComputeElem expert_result = arrayConvert<InputElem, ComputeElem>(
expanded_permuted_rows_row_ptr[elem_index]);
thread_output = thread_output + row_scale * (expert_result);
}
OutputElem output_elem =
arrayConvert<ComputeElem, OutputElem>(thread_output);
reduced_row_ptr_v[elem_index] = output_elem;
}
}
template <class T, class OutputType>
void finalizeMoeRoutingKernelLauncher(
T const* expanded_permuted_rows, OutputType* reduced_unpermuted_output,
float const* scales, int const* expanded_source_row_to_expanded_dest_row,
int const* expert_for_source_row, int64_t const num_rows,
int64_t const cols, int64_t const k, int64_t const* num_valid_ptr,
cudaStream_t stream) {
int64_t const blocks = num_rows;
int64_t const threads = 256;
bool const check_finished = num_valid_ptr != nullptr;
using FuncPtr = decltype(&finalizeMoeRoutingKernel<T, OutputType, false>);
FuncPtr func_map[2] = {&finalizeMoeRoutingKernel<T, OutputType, false>,
&finalizeMoeRoutingKernel<T, OutputType, true>};
auto* const kernel = func_map[check_finished];
kernel<<<blocks, threads, 0, stream>>>(
expanded_permuted_rows, reduced_unpermuted_output, scales,
expanded_source_row_to_expanded_dest_row, expert_for_source_row, cols, k,
num_valid_ptr);
}

View File

@@ -53,7 +53,29 @@ TORCH_LIBRARY_EXPAND(TORCH_EXTENSION_NAME, m) {
"int size_m, int size_n, int size_k,"
"bool is_full_k, bool use_atomic_add,"
"bool use_fp32_reduce, bool is_zp_float) -> Tensor");
m.def(
"marlin_gemm_moe(Tensor! a, Tensor! b_q_weights, Tensor! sorted_ids, "
"Tensor! topk_weights, Tensor! topk_ids, Tensor! b_scales, Tensor! "
"b_zeros, Tensor! g_idx, Tensor! perm, Tensor! workspace, "
"int b_q_type, SymInt size_m, "
"SymInt size_n, SymInt size_k, bool is_k_full, int num_experts, int "
"topk, "
"int moe_block_size, bool replicate_input, bool apply_weights)"
" -> Tensor");
m.def(
"moe_permute(Tensor input, Tensor topk_weight, Tensor! topk_ids,"
"Tensor token_expert_indicies, Tensor? expert_map, int n_expert,"
"int n_local_expert,"
"int topk, int? align_block_size,Tensor! permuted_input, Tensor! "
"expert_first_token_offset, Tensor! src_row_id2dst_row_id_map, Tensor! "
"m_indices)->()");
m.def(
"moe_unpermute(Tensor permuted_hidden_states, Tensor topk_weights,"
"Tensor topk_ids,Tensor src_row_id2dst_row_id_map, Tensor "
"expert_first_token_offset, int n_expert, int n_local_expert,int "
"topk, Tensor! hidden_states)->()");
// conditionally compiled so impl registration is in source file
#endif