sglang_v0.5.2/flashinfer_0.3.1/include/flashinfer/comm/trtllm_allreduce.cuh

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/*
* Copyright (c) 2022-2024, 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 <cooperative_groups.h>
#include <cuda_bf16.h>
#include <cuda_fp16.h>
#include <tuple>
#include <type_traits>
#include "../exception.h"
#include "../logging.h"
#include "../utils.cuh"
#include "../vec_dtypes.cuh"
namespace flashinfer {
namespace trtllm_allreduce {
constexpr size_t WARP_SIZE = 32;
constexpr size_t MAX_ALL_REDUCE_BLOCKS = 24;
constexpr size_t MAX_RANKS_PER_NODE = 16;
constexpr size_t DEFAULT_BLOCK_SIZE = 512;
constexpr size_t NUM_POINTERS_PER_RANK = 7;
namespace details {
static constexpr int kBytesPerAccess = 16;
static constexpr int kWarpSize = 32;
static constexpr int kMaxCtaSize = 1024;
static constexpr int kClusterMaxSize = 8;
static constexpr int kLamportTokenNumThreshold = 16;
static constexpr int kLamportHiddenSizeThreshold = 256;
} // namespace details
enum class AllReduceStrategyType : int8_t {
NCCL = 0,
MIN_LATENCY = 1,
UB = 2,
AUTO = 3,
ONESHOT = 4,
TWOSHOT = 5,
LOWPRECISION = 6,
};
enum class AllReduceStrategyConfig : int8_t {
USE_MEMCPY = 1 << 0,
PUSH_MODE = 1 << 1,
};
//////////////////////
enum class AllReduceFusionOp : int8_t {
NONE = 0,
RESIDUAL_RMS_NORM = 1,
LAST_PROCESS_FOR_UB = 2,
RESIDUAL_RMS_PREPOST_NORM = 3,
RESIDUAL_RMS_NORM_QUANT_FP8 = 4,
RESIDUAL_RMS_NORM_QUANT_NVFP4 = 5,
RESIDUAL_RMS_NORM_OUT_QUANT_FP8 = 6,
RESIDUAL_RMS_NORM_OUT_QUANT_NVFP4 = 7,
MOE_ALLREDUCE_RESIDUAL_RMS_NORM = 8,
MOE_FINALIZE_ALLREDUCE_RESIDUAL_RMS_NORM = 9,
};
template <typename T>
bool is_lamport_supported(int token_num, int hidden_size) {
if (!std::is_same_v<T, half> && !std::is_same_v<T, __nv_bfloat16>) {
return false;
}
if (token_num > details::kLamportTokenNumThreshold) {
return false;
}
if (hidden_size < details::kLamportHiddenSizeThreshold) {
return false;
}
return true;
}
struct AllReduceFusionParams {
AllReduceFusionParams()
: bias_buffer(nullptr),
residual_buffer(nullptr),
weight_buffer(nullptr),
weight_buffer_pre_residual_norm(nullptr),
intermediate_buffer(nullptr) {}
// gemm bias
void const* bias_buffer;
// residuial add
void const* residual_buffer;
// rms norm
int hidden_size; // equal to normalized_shape
void const* weight_buffer; // norm elem-wise affine gamma
void const* weight_buffer_pre_residual_norm; // for gemma norm before residual
float eps;
// new residual
void* intermediate_buffer;
void* lamport_peer_comm_buffer_ptrs[MAX_RANKS_PER_NODE * 3];
};
template <typename T>
struct AllReduceParams {
size_t elts_total;
size_t elts_per_rank;
size_t elts_per_block;
size_t rank_offset;
size_t ranks_per_node;
size_t local_rank;
uint32_t barrier_flag;
uint32_t* peer_barrier_ptrs_in[MAX_RANKS_PER_NODE];
uint32_t* peer_barrier_ptrs_out[MAX_RANKS_PER_NODE];
void* peer_comm_buffer_ptrs[MAX_RANKS_PER_NODE];
void* local_output_buffer_ptr;
void const* local_input_buffer_ptr;
AllReduceFusionParams fusion_params;
static AllReduceParams deserialize(int64_t* buffer, size_t tpSize, size_t tpRank, int token_num,
int hidden_size, AllReduceFusionOp op) {
void* const* buffer_ptrs = reinterpret_cast<void* const*>(buffer);
int flag_offset;
if (op == AllReduceFusionOp::RESIDUAL_RMS_NORM &&
is_lamport_supported<T>(token_num, hidden_size)) {
flag_offset = 0;
} else {
flag_offset = 1;
}
auto const flag_ptr = &buffer[NUM_POINTERS_PER_RANK * tpSize + flag_offset];
// cannot use 0 since 0 represents released state for barrier
*flag_ptr += 1;
uint32_t flag_value = *flag_ptr;
AllReduceParams params;
// Even plugins use ping buffers, odd plugins use pong.
// That way, we don't need to wait for other GPUs to be done
// before copying input tensor to workspace.
auto const buffer_offset = (flag_value % 2 == 0) ? 0 : tpSize;
for (int i = 0; i < tpSize; ++i) {
params.peer_comm_buffer_ptrs[i] = buffer_ptrs[buffer_offset + i];
}
for (int i = 0; i < tpSize; ++i) {
params.peer_barrier_ptrs_in[i] = reinterpret_cast<uint32_t*>(buffer_ptrs[2 * tpSize + i]);
}
for (int i = 0; i < tpSize; ++i) {
params.peer_barrier_ptrs_out[i] = reinterpret_cast<uint32_t*>(buffer_ptrs[3 * tpSize + i]);
}
params.barrier_flag = flag_value;
params.ranks_per_node = tpSize;
params.local_rank = tpRank;
return params;
}
};
////////////////////////////////////////////////////////////////////////////////////////////////////
template <typename T>
struct neg_zero {
static constexpr T value = -T(0);
};
template <>
struct neg_zero<half> {
static constexpr unsigned short neg_zero_bits = 0x8000U;
static constexpr __half value = __half_raw{neg_zero_bits};
};
template <>
struct neg_zero<nv_bfloat16> {
static constexpr unsigned short neg_zero_bits = 0x8000U;
static constexpr __nv_bfloat16 value = __nv_bfloat16_raw{neg_zero_bits};
};
template <>
struct neg_zero<float> {
static constexpr unsigned int neg_zero_bits = 0x80000000U;
static constexpr float value = -0.0f;
};
template <typename T>
__device__ static constexpr T neg_zero_v = neg_zero<T>::value;
template <typename T>
__device__ bool is_negative_zero(T) {
return false;
}
// float specialization
template <>
__device__ bool is_negative_zero<float>(float x) {
return (__float_as_int(x) == 0x80000000);
}
// double specialization
template <>
__device__ bool is_negative_zero<double>(double x) {
return (__double_as_longlong(x) == 0x8000000000000000ULL);
}
// __half specialization
template <>
__device__ bool is_negative_zero<__half>(__half x) {
return (__half_as_ushort(x) == 0x8000);
}
// __nv_bfloat16 specialization
template <>
__device__ bool is_negative_zero<__nv_bfloat16>(__nv_bfloat16 x) {
return (__bfloat16_as_ushort(x) == 0x8000);
}
template <typename T, uint32_t VEC_SIZE>
__device__ __forceinline__ bool has_neg_zero(const vec_t<T, VEC_SIZE>& vec) {
#pragma unroll
for (int i = 0; i < VEC_SIZE; ++i) {
if (is_negative_zero(vec[i])) {
return true;
}
}
return false;
}
template <typename T, uint32_t VEC_SIZE>
__device__ __forceinline__ void remove_neg_zero(vec_t<T, VEC_SIZE>& vec) {
#pragma unroll
for (int i = 0; i < VEC_SIZE; ++i) {
vec[i] = (is_negative_zero(vec[i])) ? static_cast<T>(0.f) : vec[i];
}
}
template <typename T>
__device__ __forceinline__ void set_neg_zero(T* addr) {
vec_t<T, 16 / sizeof(T)> val;
val.fill(neg_zero_v<T>);
val.store_global_volatile(addr);
}
static inline __device__ void st_flag_release(uint32_t const& flag, uint32_t* flag_addr) {
#if __CUDA_ARCH__ >= 700
asm volatile("st.global.release.sys.b32 [%1], %0;" ::"r"(flag), "l"(flag_addr));
#else
__threadfence_system();
asm volatile("st.global.volatile.b32 [%1], %0;" ::"r"(flag), "l"(flag_addr));
#endif
}
////////////////////////////////////////////////////////////////////////////////////////////////////
static inline __device__ uint32_t ld_flag_acquire(uint32_t* flag_addr) {
uint32_t flag;
#if __CUDA_ARCH__ >= 700
asm volatile("ld.global.acquire.sys.b32 %0, [%1];" : "=r"(flag) : "l"(flag_addr));
#else
asm volatile("ld.global.volatile.b32 %0, [%1];" : "=r"(flag) : "l"(flag_addr));
#endif
return flag;
}
template <typename T, uint32_t VEC_SIZE>
__device__ __forceinline__ vec_t<T, VEC_SIZE> vec_add(const vec_t<T, VEC_SIZE>& a,
const vec_t<T, VEC_SIZE>& b) {
vec_t<T, VEC_SIZE> ret;
#pragma unroll
for (int i = 0; i < VEC_SIZE; ++i) {
ret[i] = static_cast<float>(a[i]) + static_cast<float>(b[i]);
}
return ret;
}
////////////////////////////////////////////////////////////////////////////////////////////////////
__inline__ __device__ void multi_gpu_barrier(uint32_t** signals, uint32_t const flag,
size_t const local_rank, size_t const world_size,
int const tidx, int const bidx) {
// After this function, at least one block in each GPU has reached the barrier
if (tidx < world_size) {
// we can think of signals having the shape [world_size, world_size]
// Dimension 0 is the "listening" dimension, dimension 1 is "emitting" dimension
// Block 0 broadcasts its flag (local_rank on emitting dimension) to all receivers
size_t offset = (flag % 2) ? world_size : 0;
if (bidx == 0) {
st_flag_release(flag, signals[tidx] + offset + local_rank);
}
// All blocks check that corresponding block 0 on other GPUs have set the flag
// No deadlock because block #0 is always the first block started
uint32_t* peer_barrier_d = signals[local_rank] + offset + tidx;
while (ld_flag_acquire(peer_barrier_d) != flag) {
}
}
__syncthreads();
}
__inline__ __device__ void block_barrier(uint32_t** signals, uint32_t const flag,
size_t const local_rank, size_t const world_size,
int const tidx, int const bidx, int const grid_size) {
// After this function, the block of id == bidx of each GPU has reached the barrier
if (tidx < world_size) {
// we can think of signals having the shape [world_size, 2, num_blocks, world_size]
// (+ an offset on dim 2 to account for flags used in multi_gpu_barrier)
// Dimension 0 is the "listening" dimension, dimension 3 is "emitting" dimension
// Block broadcast its flag (local_rank on emitting dimension) to all receivers
uint32_t flag_block_offset = world_size + bidx * world_size;
if (flag % 2 == 1) {
flag_block_offset += (grid_size + 1) * world_size;
}
st_flag_release(flag, signals[tidx] + flag_block_offset + local_rank);
// Blocks check that corresponding blocks on other GPUs have also set the flag
uint32_t* peer_barrier_d = signals[local_rank] + flag_block_offset + tidx;
while (ld_flag_acquire(peer_barrier_d) != flag) {
}
}
__syncthreads();
}
namespace reduce_fusion {
inline __device__ float warp_reduce_sum(float val) {
val += __shfl_xor_sync(~0, val, 16);
val += __shfl_xor_sync(~0, val, 8);
val += __shfl_xor_sync(~0, val, 4);
val += __shfl_xor_sync(~0, val, 2);
val += __shfl_xor_sync(~0, val, 1);
return val;
}
inline __device__ float block_reduce_sum(float val) {
__shared__ float smem[details::kWarpSize];
int lane_id = threadIdx.x % details::kWarpSize, warp_id = threadIdx.x / details::kWarpSize,
warp_num = blockDim.x / details::kWarpSize;
val = warp_reduce_sum(val);
if (lane_id == 0) {
smem[warp_id] = val;
}
__syncthreads();
val = lane_id < warp_num ? smem[lane_id] : 0.f;
val = warp_reduce_sum(val);
return val;
}
template <typename T, uint32_t VEC_SIZE>
inline __device__ float accumulate(float acc, vec_t<T, VEC_SIZE>& vec) {
#pragma unroll
for (int i = 0; i < VEC_SIZE; ++i) {
float v = static_cast<float>(vec[i]);
acc += v * v;
}
return acc;
}
template <typename T, bool Affine, uint32_t VEC_SIZE>
inline __device__ vec_t<T, VEC_SIZE> rms_norm(float denom, vec_t<T, VEC_SIZE>& vec,
vec_t<T, VEC_SIZE>& weight) {
vec_t<T, VEC_SIZE> ret;
#pragma unroll
for (int i = 0; i < VEC_SIZE; ++i) {
float v1 = static_cast<float>(vec[i]);
if constexpr (Affine) {
float v2 = static_cast<float>(weight[i]);
ret[i] = static_cast<T>(v1 * denom * v2);
} else {
ret[i] = static_cast<T>(v1 * denom);
}
}
return ret;
}
template <typename T, bool Bias = false, bool Residual = false, bool Affine = false,
bool UseSmem = false>
__global__ void rms_norm_kernel(AllReduceParams<T> params) {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
extern __shared__ uint8_t smem_ptr[];
T* smem = reinterpret_cast<T*>(smem_ptr);
int bid = blockIdx.x, tid = threadIdx.x;
T const* bias_buffer = reinterpret_cast<T const*>(params.fusion_params.bias_buffer);
T const* residual_buffer = reinterpret_cast<T const*>(params.fusion_params.residual_buffer);
T const* weight_buffer = reinterpret_cast<T const*>(params.fusion_params.weight_buffer);
T* local_final_output_buffer = reinterpret_cast<T*>(params.local_output_buffer_ptr);
T* intermediate_buffer = reinterpret_cast<T*>(params.fusion_params.intermediate_buffer);
int block_offset = bid * params.fusion_params.hidden_size;
int thread_offset = tid * VEC_SIZE;
if constexpr (Residual) {
residual_buffer += block_offset;
}
local_final_output_buffer += block_offset;
intermediate_buffer += block_offset;
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaGridDependencySynchronize();
#endif
vec_t<T, VEC_SIZE> inter_vec, weight_vec;
float acc = 0.f;
for (int offset = thread_offset; offset < params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
inter_vec.load(intermediate_buffer + offset);
if constexpr (Bias) {
vec_t<T, VEC_SIZE> bias_vec;
bias_vec.load(bias_buffer + offset);
inter_vec = vec_add<T, VEC_SIZE>(inter_vec, bias_vec);
}
if constexpr (Residual) {
vec_t<T, VEC_SIZE> residual_vec;
residual_vec.load(residual_buffer + offset);
inter_vec = vec_add<T, VEC_SIZE>(inter_vec, residual_vec);
inter_vec.store(intermediate_buffer + offset);
}
acc = accumulate<T, VEC_SIZE>(acc, inter_vec);
if constexpr (UseSmem) {
inter_vec.store(&smem[offset]);
}
}
acc = block_reduce_sum(acc);
float denom = rsqrtf(acc / params.fusion_params.hidden_size + params.fusion_params.eps);
for (int offset = thread_offset; offset < params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
if constexpr (UseSmem) {
inter_vec.load(&smem[offset]);
}
if constexpr (Affine) {
weight_vec.load(weight_buffer + offset);
}
inter_vec = rms_norm<T, Affine, VEC_SIZE>(denom, inter_vec, weight_vec);
inter_vec.store(&local_final_output_buffer[offset]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaTriggerProgrammaticLaunchCompletion();
#endif
}
template <typename T, bool Bias = false, bool Residual = false, bool Affine = false>
__global__ void rms_pre_post_norm_kernel(
AllReduceParams<T> params) // for gemma2 pre residual + post residual norm
{
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
int bid = blockIdx.x, tid = threadIdx.x;
T const* bias_buffer = reinterpret_cast<T const*>(params.fusion_params.bias_buffer);
T const* residual_buffer = reinterpret_cast<T const*>(params.fusion_params.residual_buffer);
T const* weight_buffer = reinterpret_cast<T const*>(params.fusion_params.weight_buffer);
T const* weight_buffer_pre_residual_norm =
reinterpret_cast<T const*>(params.fusion_params.weight_buffer_pre_residual_norm);
T* local_final_output_buffer = reinterpret_cast<T*>(params.local_output_buffer_ptr);
T* intermediate_buffer = reinterpret_cast<T*>(params.fusion_params.intermediate_buffer);
int block_offset = bid * params.fusion_params.hidden_size;
int thread_offset = tid * VEC_SIZE;
if constexpr (Residual) {
residual_buffer += block_offset;
}
local_final_output_buffer += block_offset;
intermediate_buffer += block_offset;
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaGridDependencySynchronize();
#endif
vec_t<T, VEC_SIZE> inter_vec, weight_vec, weight_vec_pre_residual_norm, bias_vec;
float acc = 0.f;
float acc_pre_residual_norm = 0.f;
for (int offset = thread_offset; offset < params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
inter_vec.load(intermediate_buffer + offset);
if constexpr (Bias) {
bias_vec.load(bias_buffer + offset);
}
if constexpr (Bias) {
inter_vec = vec_add<T, VEC_SIZE>(inter_vec, bias_vec);
}
// pre-residual norm.
acc_pre_residual_norm = accumulate<T, VEC_SIZE>(acc_pre_residual_norm, inter_vec);
acc_pre_residual_norm = block_reduce_sum(acc_pre_residual_norm);
float denom_pre_residual_norm =
rsqrtf(acc_pre_residual_norm / params.fusion_params.hidden_size + params.fusion_params.eps);
if constexpr (Affine) {
weight_vec_pre_residual_norm.load(weight_buffer_pre_residual_norm + thread_offset);
}
inter_vec = rms_norm<T, Affine, VEC_SIZE>(denom_pre_residual_norm, inter_vec,
weight_vec_pre_residual_norm);
if constexpr (Residual) {
vec_t<T, VEC_SIZE> residual_vec;
residual_vec.load(residual_buffer + offset);
inter_vec = vec_add<T, VEC_SIZE>(inter_vec, residual_vec);
inter_vec.store(intermediate_buffer + offset);
}
acc = accumulate<T, VEC_SIZE>(acc, inter_vec);
}
acc = block_reduce_sum(acc);
float denom = rsqrtf(acc / params.fusion_params.hidden_size + params.fusion_params.eps);
for (int offset = thread_offset; offset < params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
if constexpr (Affine) {
weight_vec.load(weight_buffer + offset);
}
inter_vec = rms_norm<T, Affine, VEC_SIZE>(denom, inter_vec, weight_vec);
inter_vec.store(&local_final_output_buffer[offset]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaTriggerProgrammaticLaunchCompletion();
#endif
}
template <typename T, bool Bias = false, bool Residual = false, bool Affine = false>
cudaError_t rms_norm_kernel_launcher(AllReduceParams<T>& params, AllReduceFusionOp fusionOp,
bool launch_with_pdl, cudaStream_t stream) {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
FLASHINFER_CHECK(params.fusion_params.hidden_size % VEC_SIZE == 0,
"hidden_size must be a multiple of ", VEC_SIZE);
if (fusionOp == AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM) {
FLASHINFER_CHECK(params.fusion_params.hidden_size <= 8192,
"hidden_size must be less than or equal to 8192");
}
int need_threads = params.fusion_params.hidden_size / VEC_SIZE;
int cta_size;
if (need_threads <= details::kMaxCtaSize) {
cta_size = (need_threads + details::kWarpSize - 1) / details::kWarpSize * details::kWarpSize;
} else {
cta_size = details::kMaxCtaSize;
}
int cta_num = params.elts_total / params.fusion_params.hidden_size;
int smem_size = 0;
if (cta_size * details::kBytesPerAccess / sizeof(T) < params.fusion_params.hidden_size) {
smem_size = params.fusion_params.hidden_size * sizeof(T);
cudaLaunchConfig_t kernelConfig = {0};
kernelConfig.gridDim = cta_num;
kernelConfig.blockDim = cta_size;
kernelConfig.dynamicSmemBytes = smem_size;
kernelConfig.stream = stream;
cudaLaunchAttribute attribute[1];
attribute[0].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[0].val.programmaticStreamSerializationAllowed = launch_with_pdl;
kernelConfig.attrs = attribute;
kernelConfig.numAttrs = 1;
if (fusionOp == AllReduceFusionOp::RESIDUAL_RMS_NORM) {
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, rms_norm_kernel<T, Bias, Residual, Affine, true>, params));
} else { // AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, rms_pre_post_norm_kernel<T, Bias, Residual, Affine>, params));
}
} else {
cudaLaunchConfig_t kernelConfig = {0};
kernelConfig.gridDim = cta_num;
kernelConfig.blockDim = cta_size;
kernelConfig.dynamicSmemBytes = smem_size;
kernelConfig.stream = stream;
cudaLaunchAttribute attribute[1];
attribute[0].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[0].val.programmaticStreamSerializationAllowed = launch_with_pdl;
kernelConfig.attrs = attribute;
kernelConfig.numAttrs = 1;
if (fusionOp == AllReduceFusionOp::RESIDUAL_RMS_NORM) {
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, rms_norm_kernel<T, Bias, Residual, Affine, false>, params));
} else { // AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, rms_pre_post_norm_kernel<T, Bias, Residual, Affine>, params));
}
}
return cudaSuccess;
}
template <typename T, int RanksPerNode, bool PushMode>
struct Reducer;
template <typename T, int RanksPerNode>
struct Reducer<T, RanksPerNode, true> {
constexpr static uint32_t VEC_SIZE = 16 / sizeof(T);
static __device__ __forceinline__ vec_t<T, VEC_SIZE> allreduce(AllReduceParams<T>& params,
int global_offset) {
int ping = params.barrier_flag % 3;
int pong = (params.barrier_flag + 2) % 3;
T const* local_input_buffer = reinterpret_cast<T const*>(params.local_input_buffer_ptr);
T* local_shared_buffer = reinterpret_cast<T*>(
params.fusion_params
.lamport_peer_comm_buffer_ptrs[params.local_rank + ping * MAX_RANKS_PER_NODE]);
T* local_clean_buffer = reinterpret_cast<T*>(
params.fusion_params
.lamport_peer_comm_buffer_ptrs[params.local_rank + pong * MAX_RANKS_PER_NODE]);
local_input_buffer += global_offset;
local_shared_buffer += global_offset;
local_clean_buffer += global_offset;
T* buffers[RanksPerNode];
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
int rank = (params.local_rank + ii) % RanksPerNode;
buffers[ii] = reinterpret_cast<T*>(
params.fusion_params
.lamport_peer_comm_buffer_ptrs[rank + ping * MAX_RANKS_PER_NODE]) +
global_offset + params.local_rank * params.elts_total;
}
vec_t<T, VEC_SIZE> sum_vec, val;
val.load(local_input_buffer);
#pragma unroll
for (int ii = 1; ii < RanksPerNode; ++ii) {
val.store_global_volatile(buffers[ii]);
}
sum_vec = val;
#pragma unroll
for (int ii = 1; ii < RanksPerNode; ++ii) {
int rank = (params.local_rank + ii) % RanksPerNode;
set_neg_zero<T>(local_clean_buffer + rank * params.elts_total);
}
vec_t<T, VEC_SIZE> vals[RanksPerNode - 1];
bool done = false;
while (!done) {
done = true;
#pragma unroll
for (int ii = 1; ii < RanksPerNode; ++ii) {
int rank = (params.local_rank + ii) % RanksPerNode;
vals[ii - 1].load_global_volatile(local_shared_buffer + rank * params.elts_total);
}
#pragma unroll
for (int ii = 0; ii < RanksPerNode - 1; ii++) {
done &= !has_neg_zero<T, VEC_SIZE>(vals[ii]);
}
}
#pragma unroll
for (int ii = 1; ii < RanksPerNode; ++ii) {
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, vals[ii - 1]);
}
return sum_vec;
}
};
template <typename T, int RanksPerNode>
struct Reducer<T, RanksPerNode, false> {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
static __device__ __forceinline__ vec_t<T, VEC_SIZE> allreduce(AllReduceParams<T>& params,
int global_offset) {
int ping = params.barrier_flag % 3;
int pong = (params.barrier_flag + 2) % 3;
T const* local_input_buffer = reinterpret_cast<T const*>(params.local_input_buffer_ptr);
T* local_shared_buffer = reinterpret_cast<T*>(
params.fusion_params
.lamport_peer_comm_buffer_ptrs[params.local_rank + ping * MAX_RANKS_PER_NODE]);
T* local_clean_buffer = reinterpret_cast<T*>(
params.fusion_params
.lamport_peer_comm_buffer_ptrs[params.local_rank + pong * MAX_RANKS_PER_NODE]);
local_input_buffer += global_offset;
local_shared_buffer += global_offset;
local_clean_buffer += global_offset;
T* buffers[RanksPerNode];
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
int rank = (params.local_rank + ii) % RanksPerNode;
buffers[ii] = reinterpret_cast<T*>(
params.fusion_params
.lamport_peer_comm_buffer_ptrs[rank + ping * MAX_RANKS_PER_NODE]) +
global_offset;
}
vec_t<T, VEC_SIZE> sum_vec, val;
val.load(local_input_buffer);
val.store_global_volatile(reinterpret_cast<int4*>(local_shared_buffer));
sum_vec = val;
#pragma unroll
for (int ii = 1; ii < RanksPerNode; ++ii) {
do {
val.load_global_volatile(reinterpret_cast<int4*>(buffers[ii]));
} while (has_neg_zero<T, VEC_SIZE>(val));
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, val);
}
set_neg_zero<T>(local_clean_buffer);
return sum_vec;
}
};
template <int ClusterSize, typename T, int RanksPerNode, bool Bias = false, bool Affine = false,
bool PushMode = true>
__global__ void lamport_style_one_shot_all_reduce_norm_kernel(AllReduceParams<T> params) {
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
namespace cg = cooperative_groups;
static_assert(RanksPerNode <= MAX_RANKS_PER_NODE);
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
cg::cluster_group cluster = cg::this_cluster();
__shared__ float cluster_acc, cluster_acc_sum;
int bid = blockIdx.x, tid = threadIdx.x;
int cluster_id = bid / ClusterSize, cluster_block_rank = bid % ClusterSize;
int token_id = cluster_id;
int cluster_offset = token_id * params.fusion_params.hidden_size;
int block_offset = cluster_block_rank * params.fusion_params.hidden_size / ClusterSize;
int thread_offset = tid * VEC_SIZE;
int inner_token_offset = block_offset + thread_offset;
int global_offset = cluster_offset + inner_token_offset;
T const* bias_buffer = reinterpret_cast<T const*>(params.fusion_params.bias_buffer);
T const* residual_buffer = reinterpret_cast<T const*>(params.fusion_params.residual_buffer);
T const* weight_buffer = reinterpret_cast<T const*>(params.fusion_params.weight_buffer);
T* local_final_output_buffer = reinterpret_cast<T*>(params.local_output_buffer_ptr);
T* intermediate_buffer = reinterpret_cast<T*>(params.fusion_params.intermediate_buffer);
local_final_output_buffer += global_offset;
intermediate_buffer += global_offset;
residual_buffer += global_offset;
bias_buffer += inner_token_offset;
weight_buffer += inner_token_offset;
vec_t<T, VEC_SIZE> weight_vec, bias_vec, residual_vec;
residual_vec.load(residual_buffer);
if constexpr (Bias) {
bias_vec.load(bias_buffer);
}
if constexpr (Affine) {
weight_vec.load(weight_buffer);
}
cudaGridDependencySynchronize();
float acc = 0.f;
vec_t<T, VEC_SIZE> sum_vec;
sum_vec = Reducer<T, RanksPerNode, PushMode>::allreduce(params, global_offset);
if constexpr (Bias) {
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, bias_vec);
}
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, residual_vec);
sum_vec.store(intermediate_buffer);
acc = accumulate<T, VEC_SIZE>(acc, sum_vec);
acc = block_reduce_sum(acc);
if (ClusterSize > 1) {
if (threadIdx.x == 0) {
cluster_acc = acc;
}
cluster.sync();
if (threadIdx.x == 0) {
acc = 0.f;
#pragma unroll
for (int ii = 0; ii < ClusterSize; ++ii) {
acc += *cluster.map_shared_rank(&cluster_acc, ii);
}
cluster_acc_sum = acc;
}
__syncthreads();
acc = cluster_acc_sum;
cluster.sync();
}
float denom = rsqrtf(acc / params.fusion_params.hidden_size + params.fusion_params.eps);
sum_vec = rms_norm<T, Affine, VEC_SIZE>(denom, sum_vec, weight_vec);
sum_vec.store(local_final_output_buffer);
cudaTriggerProgrammaticLaunchCompletion();
#endif
}
int heuristic_min_warp_number(int tp_size, int hidden_size) {
if (hidden_size >= 4096) {
return 4;
}
if (tp_size == 2) {
return 32;
} else {
return 16;
}
}
template <typename T, int RanksPerNode, bool Bias, bool Affine>
cudaError_t lamport_style_one_shot_all_reduce_norm_kernel_launcher(AllReduceParams<T> params,
bool launch_with_pdl,
cudaStream_t stream) {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
FLASHINFER_CHECK(params.fusion_params.hidden_size % VEC_SIZE == 0,
"hidden_size must be a multiple of ", VEC_SIZE);
int threads_per_token = params.fusion_params.hidden_size / VEC_SIZE;
int warps_per_token = (threads_per_token + details::kWarpSize - 1) / details::kWarpSize;
int token_num = params.elts_total / params.fusion_params.hidden_size;
int warp_min_number = heuristic_min_warp_number(RanksPerNode, params.fusion_params.hidden_size);
int cluster_size = std::min(((warps_per_token + warp_min_number - 1) / warp_min_number),
details::kClusterMaxSize);
int cta_size = warps_per_token / cluster_size * details::kWarpSize;
FLASHINFER_CHECK(cta_size <= details::kMaxCtaSize, "cta_size must be less than or equal to ",
details::kMaxCtaSize);
int cta_num = token_num * cluster_size;
cudaLaunchConfig_t kernel_config = {0};
kernel_config.gridDim = cta_num;
kernel_config.blockDim = cta_size;
kernel_config.dynamicSmemBytes = 0;
kernel_config.stream = stream;
cudaLaunchAttribute attribute[2];
attribute[0].id = cudaLaunchAttributeClusterDimension;
attribute[0].val.clusterDim.x = cluster_size;
attribute[0].val.clusterDim.y = 1;
attribute[0].val.clusterDim.z = 1;
kernel_config.attrs = attribute;
kernel_config.numAttrs = 1;
if (launch_with_pdl) {
attribute[1].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[1].val.programmaticStreamSerializationAllowed = 1;
kernel_config.numAttrs++;
}
#define LAUNCH_LAMPORT_KERNEL(CLUSTER_SIZE) \
if (cluster_size == CLUSTER_SIZE) { \
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx( \
&kernel_config, \
lamport_style_one_shot_all_reduce_norm_kernel<CLUSTER_SIZE, T, RanksPerNode, Bias, \
Affine>, \
params)); \
return cudaSuccess; \
}
LAUNCH_LAMPORT_KERNEL(1);
LAUNCH_LAMPORT_KERNEL(2);
LAUNCH_LAMPORT_KERNEL(3);
LAUNCH_LAMPORT_KERNEL(4);
LAUNCH_LAMPORT_KERNEL(5);
LAUNCH_LAMPORT_KERNEL(6);
LAUNCH_LAMPORT_KERNEL(7);
LAUNCH_LAMPORT_KERNEL(8);
#undef LAUNCH_LAMPORT_KERNEL
}
template <typename T, int RanksPerNode, bool Bias = false, bool Affine = false,
bool UseSmem = false>
__global__ void __launch_bounds__(1024, 1)
one_shot_all_reduce_norm_kernel(AllReduceParams<T> params) {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
extern __shared__ uint8_t smem_ptr[];
T* smem = reinterpret_cast<T*>(smem_ptr);
int bid = blockIdx.x, tid = threadIdx.x;
int norm_num = params.elts_total / params.fusion_params.hidden_size;
int norm_per_block = (norm_num + gridDim.x - 1) / gridDim.x;
int norm_this_block = std::min(norm_per_block, norm_num - bid * norm_per_block);
T const* local_input_buffer = reinterpret_cast<T const*>(params.local_input_buffer_ptr);
T const* bias_buffer = reinterpret_cast<T const*>(params.fusion_params.bias_buffer);
T const* residual_buffer = reinterpret_cast<T const*>(params.fusion_params.residual_buffer);
T const* weight_buffer = reinterpret_cast<T const*>(params.fusion_params.weight_buffer);
T* local_shared_buffer = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[params.local_rank]);
T* local_final_output_buffer = reinterpret_cast<T*>(params.local_output_buffer_ptr);
T* intermediate_buffer = reinterpret_cast<T*>(params.fusion_params.intermediate_buffer);
int block_offset = bid * norm_per_block * params.fusion_params.hidden_size;
int thread_offset = tid * VEC_SIZE;
local_input_buffer += block_offset;
residual_buffer += block_offset;
local_shared_buffer += block_offset;
local_final_output_buffer += block_offset;
intermediate_buffer += block_offset;
T* buffers[RanksPerNode];
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
int rank = (params.local_rank + ii) % RanksPerNode;
buffers[ii] = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[rank]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaGridDependencySynchronize();
#endif
for (int offset = thread_offset; offset < norm_this_block * params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
*reinterpret_cast<int4*>(&local_shared_buffer[offset]) =
*reinterpret_cast<int4 const*>(&local_input_buffer[offset]);
}
block_barrier(params.peer_barrier_ptrs_in, params.barrier_flag, params.local_rank, RanksPerNode,
tid, bid, gridDim.x);
for (int norm_idx = 0; norm_idx < norm_this_block; ++norm_idx) {
int norm_offset = norm_idx * params.fusion_params.hidden_size;
float acc = 0.f;
vec_t<T, VEC_SIZE> sum_vec, weight_vec, bias_vec, residual_vec;
for (int offset = thread_offset; offset < params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
vec_t<T, VEC_SIZE> vals[RanksPerNode];
sum_vec.fill(T(0));
if constexpr (Bias) {
bias_vec.load(bias_buffer + offset);
}
residual_vec.load(residual_buffer + norm_offset + offset);
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
vals[ii].load(buffers[ii] + block_offset + norm_offset + offset);
}
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, vals[ii]);
}
if constexpr (Bias) {
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, bias_vec);
}
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, residual_vec);
sum_vec.store(&intermediate_buffer[norm_offset + offset]);
acc = accumulate<T, VEC_SIZE>(acc, sum_vec);
if constexpr (UseSmem) {
sum_vec.store(&smem[offset]);
}
}
acc = block_reduce_sum(acc);
float denom = rsqrtf(acc / params.fusion_params.hidden_size + params.fusion_params.eps);
for (int offset = thread_offset; offset < params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
if constexpr (UseSmem) {
sum_vec.load(&smem[offset]);
}
if constexpr (Affine) {
weight_vec.load(weight_buffer + offset);
}
sum_vec = rms_norm<T, Affine, VEC_SIZE>(denom, sum_vec, weight_vec);
sum_vec.store(&local_final_output_buffer[norm_offset + offset]);
}
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaTriggerProgrammaticLaunchCompletion();
#endif
}
template <typename T, int RanksPerNode, bool Bias = false, bool Affine = false>
__global__ void __launch_bounds__(1024, 1)
one_shot_prenorm_all_reduce_norm_kernel(AllReduceParams<T> params) {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
int bid = blockIdx.x, tid = threadIdx.x;
int norm_num = params.elts_total / params.fusion_params.hidden_size;
int norm_per_block = (norm_num + gridDim.x - 1) / gridDim.x;
int norm_this_block = std::min(norm_per_block, norm_num - bid * norm_per_block);
T const* local_input_buffer = reinterpret_cast<T const*>(params.local_input_buffer_ptr);
T const* bias_buffer = reinterpret_cast<T const*>(params.fusion_params.bias_buffer);
T const* residual_buffer = reinterpret_cast<T const*>(params.fusion_params.residual_buffer);
T const* weight_buffer = reinterpret_cast<T const*>(params.fusion_params.weight_buffer);
T const* weight_buffer_pre_residual_norm =
reinterpret_cast<T const*>(params.fusion_params.weight_buffer_pre_residual_norm);
T* local_shared_buffer = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[params.local_rank]);
T* local_final_output_buffer = reinterpret_cast<T*>(params.local_output_buffer_ptr);
T* intermediate_buffer = reinterpret_cast<T*>(params.fusion_params.intermediate_buffer);
int block_offset = bid * norm_per_block * params.fusion_params.hidden_size;
int thread_offset = tid * VEC_SIZE;
local_input_buffer += block_offset;
residual_buffer += block_offset;
local_shared_buffer += block_offset;
local_final_output_buffer += block_offset;
intermediate_buffer += block_offset;
T* buffers[RanksPerNode];
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
int rank = (params.local_rank + ii) % RanksPerNode;
buffers[ii] = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[rank]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaGridDependencySynchronize();
#endif
for (int offset = thread_offset; offset < norm_this_block * params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
*reinterpret_cast<int4*>(&local_shared_buffer[offset]) =
*reinterpret_cast<int4 const*>(&local_input_buffer[offset]);
}
block_barrier(params.peer_barrier_ptrs_in, params.barrier_flag, params.local_rank, RanksPerNode,
tid, bid, gridDim.x);
for (int norm_idx = 0; norm_idx < norm_this_block; ++norm_idx) {
int norm_offset = norm_idx * params.fusion_params.hidden_size;
float acc = 0.f;
float acc_pre_residual_norm = 0.f;
vec_t<T, VEC_SIZE> sum_vec, weight_vec, bias_vec, residual_vec, weight_vec_pre_residual_norm;
for (int offset = thread_offset; offset < params.fusion_params.hidden_size;
offset += blockDim.x * VEC_SIZE) {
vec_t<T, VEC_SIZE> vals[RanksPerNode];
sum_vec.fill(T(0));
if constexpr (Bias) {
bias_vec.load(bias_buffer + offset);
}
residual_vec.load(residual_buffer + norm_offset + offset);
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
vals[ii].load(buffers[ii] + block_offset + norm_offset + offset);
}
#pragma unroll
for (int ii = 0; ii < RanksPerNode; ++ii) {
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, vals[ii]);
}
if constexpr (Bias) {
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, bias_vec);
}
// norm1 is pre-residual norm.
acc_pre_residual_norm = accumulate<T, VEC_SIZE>(acc_pre_residual_norm, sum_vec);
acc_pre_residual_norm = block_reduce_sum(acc_pre_residual_norm);
float denom_pre_residual_norm = rsqrtf(
acc_pre_residual_norm / params.fusion_params.hidden_size + params.fusion_params.eps);
if constexpr (Affine) {
weight_vec_pre_residual_norm.load(weight_buffer_pre_residual_norm + thread_offset);
}
sum_vec = rms_norm<T, Affine, VEC_SIZE>(denom_pre_residual_norm, sum_vec,
weight_vec_pre_residual_norm);
sum_vec = vec_add<T, VEC_SIZE>(sum_vec, residual_vec);
sum_vec.store(&intermediate_buffer[norm_offset + offset]);
acc = accumulate<T, VEC_SIZE>(acc, sum_vec);
}
acc = block_reduce_sum(acc);
float denom = rsqrtf(acc / params.fusion_params.hidden_size + params.fusion_params.eps);
if constexpr (Affine) {
weight_vec.load(weight_buffer + thread_offset);
}
sum_vec = rms_norm<T, Affine, VEC_SIZE>(denom, sum_vec, weight_vec);
sum_vec.store(&local_final_output_buffer[norm_offset + thread_offset]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaTriggerProgrammaticLaunchCompletion();
#endif
}
template <typename T, int RanksPerNode, bool Bias, bool Affine>
cudaError_t one_shot_all_reduce_norm_kernel_launcher(AllReduceParams<T>& params,
AllReduceFusionOp fusionOp,
bool launch_with_pdl, cudaStream_t stream) {
int token_num = params.elts_total / params.fusion_params.hidden_size;
if (fusionOp == AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM) {
FLASHINFER_CHECK(params.fusion_params.hidden_size <= 8192,
"hidden_size must be less than or equal to 8192");
}
if (is_lamport_supported<T>(token_num, params.fusion_params.hidden_size) &&
(fusionOp != AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM)) {
lamport_style_one_shot_all_reduce_norm_kernel_launcher<T, RanksPerNode, Bias, Affine>(
params, launch_with_pdl, stream);
} else {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
FLASHINFER_CHECK(params.fusion_params.hidden_size % VEC_SIZE == 0,
"hidden_size must be a multiple of ", VEC_SIZE);
int need_threads = params.fusion_params.hidden_size / VEC_SIZE;
int cta_size;
if (need_threads <= details::kMaxCtaSize) {
cta_size = (need_threads + details::kWarpSize - 1) / details::kWarpSize * details::kWarpSize;
} else {
cta_size = details::kMaxCtaSize;
}
int norm_num = params.elts_total / params.fusion_params.hidden_size;
int cta_num = std::min(norm_num, static_cast<int>(MAX_ALL_REDUCE_BLOCKS));
int smem_size = 0;
if (cta_size * VEC_SIZE < params.fusion_params.hidden_size) {
smem_size = params.fusion_params.hidden_size * sizeof(T);
cudaLaunchConfig_t kernelConfig = {0};
kernelConfig.gridDim = cta_num;
kernelConfig.blockDim = cta_size;
kernelConfig.dynamicSmemBytes = smem_size;
kernelConfig.stream = stream;
cudaLaunchAttribute attribute[1];
attribute[0].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[0].val.programmaticStreamSerializationAllowed = launch_with_pdl;
kernelConfig.attrs = attribute;
kernelConfig.numAttrs = 1;
if (fusionOp == AllReduceFusionOp::RESIDUAL_RMS_NORM) {
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, one_shot_all_reduce_norm_kernel<T, RanksPerNode, Bias, Affine, true>,
params));
} else { // fusionOp == AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, one_shot_prenorm_all_reduce_norm_kernel<T, RanksPerNode, Bias, Affine>,
params));
}
} else {
cudaLaunchConfig_t kernelConfig = {0};
kernelConfig.gridDim = cta_num;
kernelConfig.blockDim = cta_size;
kernelConfig.dynamicSmemBytes = smem_size;
kernelConfig.stream = stream;
cudaLaunchAttribute attribute[1];
attribute[0].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[0].val.programmaticStreamSerializationAllowed = launch_with_pdl;
kernelConfig.attrs = attribute;
kernelConfig.numAttrs = 1;
if (fusionOp == AllReduceFusionOp::RESIDUAL_RMS_NORM) {
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, one_shot_all_reduce_norm_kernel<T, RanksPerNode, Bias, Affine, false>,
params));
} else { // fusionOp == AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig, one_shot_prenorm_all_reduce_norm_kernel<T, RanksPerNode, Bias, Affine>,
params));
}
}
}
return cudaSuccess;
}
template <typename T>
__global__ void lamport_initialize_kernel(T* buffer, size_t size) {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
for (size_t offset = (blockIdx.x * blockDim.x + threadIdx.x) * VEC_SIZE; offset < size;
offset += gridDim.x * blockDim.x * VEC_SIZE) {
set_neg_zero<T>(&buffer[offset]);
}
}
template <typename T>
cudaError_t lamport_initialize_kernel_launcher(void* buffer, size_t size, cudaStream_t stream) {
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
int block_size = 1024;
int grid_size = (size + 1024 * VEC_SIZE - 1) / (1024 * VEC_SIZE);
lamport_initialize_kernel<T>
<<<grid_size, block_size, 0, stream>>>(reinterpret_cast<T*>(buffer), size);
auto status = cudaGetLastError();
return status;
}
}; // namespace reduce_fusion
template <typename T, int RANKS_PER_NODE, bool COPY_INPUT = true, bool PUSH_MODE = false>
static __global__ void oneShotAllReduceKernel(AllReduceParams<T> params) {
// Suppose that two GPUs participate in the AR exchange, and we start four blocks.
// The message is partitioned into chunks as detailed below:
// message
// |-------------------|
// GPU 0 | B0 | B1 | B2 | B3 |
// GPU 1 | B0 | B1 | B2 | B3 |
//
// Here the step-by-step behavior of one block:
// 1. B0 copies the chunk it is responsible for, from local_input to shareable buffer
// 2. B0 on GPU 0 and B0 on GPU 1 wait for each other (block_barrier)
// 3. B0 on GPU 0 pull and sum the chunk from GPU 1, writes the result to local_output
//
// With COPY_INPUT == false, skip step 1. and use gpu_barrier instead of block barrier during
// step 2. We only to know if the other GPU as arrived at the AR kernel, that would mean that data
// is ready
//
// With PUSH_MODE, we consider that the shared buffer is of size:
// params.peer_comm_buffer_ptrs: [world_size, world_size, message_size]
//
// Here the step-by-step behavior of one block:
// 1. B0 push the chunk is it responsible for into all other GPUs:
// params.peer_comm_buffer_ptrs[:, local_gpu, B0 slice]
// 2. block sync so the block is shared by other GPUs
// 3. Reduce along second dimension params.peer_comm_buffer_ptrs[local_gpu, :, B0 slice]
int const bidx = blockIdx.x;
int const tidx = threadIdx.x;
int const grid_size = gridDim.x;
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
T const* local_input_buffer = reinterpret_cast<T const*>(params.local_input_buffer_ptr);
T* local_shared_buffer = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[params.local_rank]);
T* local_output_buffer = reinterpret_cast<T*>(params.local_output_buffer_ptr);
// Start and end offsets of the thread
size_t const chunk_start = bidx * params.elts_per_block + tidx * VEC_SIZE;
size_t const chunk_end = std::min((bidx + 1) * params.elts_per_block, params.elts_total);
T* buffers[RANKS_PER_NODE];
#pragma unroll
for (int ii = 0; ii < RANKS_PER_NODE; ++ii) {
// buffers[0] is always the local buffers. Helps load balancing reads.
int rank = (params.local_rank + ii) % RANKS_PER_NODE;
buffers[ii] = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[rank]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaGridDependencySynchronize();
#endif
if constexpr (PUSH_MODE || COPY_INPUT) {
// Copy from local buffer to shareable buffer
for (size_t iter_offset = chunk_start; iter_offset < chunk_end;
iter_offset += blockDim.x * VEC_SIZE) {
if constexpr (PUSH_MODE) {
#pragma unroll
for (int ii = 0; ii < RANKS_PER_NODE; ++ii) {
*reinterpret_cast<int4*>(
&buffers[ii][params.local_rank * params.elts_total + iter_offset]) =
*reinterpret_cast<int4 const*>(&local_input_buffer[iter_offset]);
}
} else {
*reinterpret_cast<int4*>(&local_shared_buffer[iter_offset]) =
*reinterpret_cast<int4 const*>(&local_input_buffer[iter_offset]);
}
}
// wait for equivalent blocks of other GPUs to have copied data to their shareable buffer
block_barrier(params.peer_barrier_ptrs_in, params.barrier_flag, params.local_rank,
RANKS_PER_NODE, tidx, bidx, grid_size);
} else {
// In the non-copy case, we assume that once the kernel has been started, data is ready to be
// consumed
multi_gpu_barrier(params.peer_barrier_ptrs_in, params.barrier_flag, params.local_rank,
RANKS_PER_NODE, tidx, bidx);
}
// Each block accumulates the values from the different GPUs on the same node.
for (size_t iter_offset = chunk_start; iter_offset < chunk_end;
iter_offset += blockDim.x * VEC_SIZE) {
// Iterate over the different ranks/devices on the node to load the values.
vec_t<T, VEC_SIZE> vals[RANKS_PER_NODE];
#pragma unroll
for (int ii = 0; ii < RANKS_PER_NODE; ++ii) {
if constexpr (PUSH_MODE) {
vals[ii].load(&buffers[params.local_rank][ii * params.elts_total + iter_offset]);
} else {
vals[ii].load(&buffers[ii][iter_offset]);
}
}
// Sum the values from the different ranks.
vec_t<T, VEC_SIZE> sums;
sums.fill(T(0));
#pragma unroll
for (int rank = 0; rank < RANKS_PER_NODE; ++rank) {
// Always reduce from rank 0 to ensure stable reduce order.
int ii = (rank + RANKS_PER_NODE - params.local_rank) % RANKS_PER_NODE;
sums = vec_add<T, VEC_SIZE>(sums, vals[ii]);
}
// Store to the destination buffer.
sums.store(&local_output_buffer[iter_offset]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaTriggerProgrammaticLaunchCompletion();
#endif
}
template <typename T, int RANKS_PER_NODE, bool COPY_INPUT = true, bool PUSH_MODE = false,
bool Bias = false, bool Residual = false>
static __global__ void __launch_bounds__(512, 1) twoShotAllReduceKernel(AllReduceParams<T> params) {
// Suppose that two GPUs participate in the AR exchange, and we start two blocks.
// The message is partitioned into chunks as detailed below:
// message
// |-------------------|
// |--GPU 0--|--GPU 1--| (GPU responsibility parts)
// GPU 0 | B0 | B1 | B0 | B1 |
// GPU 1 | B0 | B1 | B0 | B1 |
//
// Here the step-by-step behavior of one block:
// 1. B0 copies all chunks is it responsible for, from local_input to shareable buffer
// 2. B0 on GPU 0 and B0 on GPU 1 wait for each other (block_barrier #0)
// 3. B0 on GPU 0 gather and sum the B0 chunks from GPU 1, that are in the GPU 0 responsibility
// part (the first half of the message, see GPU responsibility row above)
// 3bis. Likewise, B0 on GPU 1 copies and sum the chunks for GPU 0,
// where GPU 1 is responsible: the second half of the message.
// 4. B0 on GPU 0 and B0 on GPU 1 wait for each other (block_barrier #1)
// 5. B0 writes result to local_output. It gathers each chunk from its responsible GPU.
// For example, here it reads the first chunk from GPU 0 and second chunk from GPU 1.
//
// With COPY_INPUT == false, skip step 1. and use gpu_barrier instead of block barrier during
// step 2. We only to know if the other GPU as arrived at the AR kernel, that would mean that data
// is ready to be read.
//
// Note that compared to one-shot, one block (CTA) writes multiple input chunks and write multiple
// output chunks. However, it's only responsible for the summation of a single chunk.
//
// With PUSH_MODE, we consider that the shared buffer is of size:
// params.peer_comm_buffer_ptrs: [world_size, world_size, message_size / world_size]
//
// Here the step-by-step behavior of one block:
// 1. B0 push the chunks is it responsible for into the corresponding GPUs:
// params.peer_comm_buffer_ptrs[target_gpu, local_gpu, current B0 slice]
// 2. block sync so the blocks have been shared by other GPUs
// 3. Reduce along second dimension params.peer_comm_buffer_ptrs[local_gpu, :, B0 slice]
// 4. block barrier (corresponding blocks have finished reduction)
// 5. pull and write on local buffer, by reading params.peer_comm_buffer_ptrs[:, 0, B0 slice]
// (reduction result is
// written at index 0 of 2nd dim)
int const bidx = blockIdx.x;
int const tidx = threadIdx.x;
int const grid_size = gridDim.x;
static constexpr uint32_t VEC_SIZE = 16 / sizeof(T);
T const* local_input_buffer = reinterpret_cast<T const*>(params.local_input_buffer_ptr);
T* local_shared_buffer = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[params.local_rank]);
T* local_output_buffer = reinterpret_cast<T*>(params.local_output_buffer_ptr);
size_t const chunk_start = bidx * params.elts_per_block + tidx * VEC_SIZE;
size_t const chunk_end = min(chunk_start + params.elts_per_block, params.elts_per_rank);
T* buffers[RANKS_PER_NODE];
int ranks[RANKS_PER_NODE];
#pragma unroll
for (int ii = 0; ii < RANKS_PER_NODE; ++ii) {
// A mapping of the ranks to scatter reads as much as possible
int rank = (params.local_rank + ii) % RANKS_PER_NODE;
ranks[ii] = rank;
buffers[ii] = reinterpret_cast<T*>(params.peer_comm_buffer_ptrs[rank]);
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaGridDependencySynchronize();
#endif
if constexpr (PUSH_MODE || COPY_INPUT) {
// Copy all blocks from local buffer to shareable buffer
for (size_t local_offset = chunk_start; local_offset < chunk_end;
local_offset += blockDim.x * VEC_SIZE) {
#pragma unroll
for (int ii = 0; ii < RANKS_PER_NODE; ++ii) {
size_t offset_rank = ranks[ii] * params.elts_per_rank + local_offset;
if (offset_rank >= params.elts_total) {
continue;
}
if constexpr (PUSH_MODE) {
*reinterpret_cast<int4*>(
&buffers[ii][params.local_rank * params.elts_per_rank + local_offset]) =
*reinterpret_cast<int4 const*>(&local_input_buffer[offset_rank]);
} else {
*reinterpret_cast<int4*>(&local_shared_buffer[offset_rank]) =
*reinterpret_cast<int4 const*>(&local_input_buffer[offset_rank]);
}
}
}
block_barrier(params.peer_barrier_ptrs_in, params.barrier_flag, params.local_rank,
RANKS_PER_NODE, tidx, bidx, grid_size);
} else {
// In the non-copy case, we assume that once the kernel has been started, data is ready to be
// consumed
multi_gpu_barrier(params.peer_barrier_ptrs_in, params.barrier_flag, params.local_rank,
RANKS_PER_NODE, tidx, bidx);
}
// Each block accumulates the values from the different GPUs on the same node.
for (size_t local_offset = chunk_start; local_offset < chunk_end;
local_offset += blockDim.x * VEC_SIZE) {
size_t const responsible_block_offset = local_offset + params.rank_offset;
// Iterate over the different ranks/devices on the node to load the values.
vec_t<T, VEC_SIZE> vals[RANKS_PER_NODE];
#pragma unroll
for (int ii = 0; ii < RANKS_PER_NODE; ++ii) {
if constexpr (PUSH_MODE) {
vals[ii].load(&local_shared_buffer[ii * params.elts_per_rank + local_offset]);
} else {
vals[ii].load(&buffers[ii][responsible_block_offset]);
}
}
// Sum the values from the different ranks.
vec_t<T, VEC_SIZE> sums;
sums.fill(T(0));
#pragma unroll
for (int rank = 0; rank < RANKS_PER_NODE; ++rank) {
// Always reduce from rank 0 to ensure stable reduce order.
int ii = (rank + RANKS_PER_NODE - params.local_rank) % RANKS_PER_NODE;
sums = vec_add<T, VEC_SIZE>(sums, vals[ii]);
}
// Store to the local buffer.
if constexpr (PUSH_MODE) {
sums.store(&local_shared_buffer[local_offset]);
} else {
sums.store(&local_shared_buffer[responsible_block_offset]);
}
}
block_barrier(params.peer_barrier_ptrs_out, params.barrier_flag, params.local_rank,
RANKS_PER_NODE, tidx, bidx, grid_size);
// Gather all needed elts from other intra-node ranks
for (size_t local_offset = chunk_start; local_offset < chunk_end;
local_offset += blockDim.x * VEC_SIZE) {
#pragma unroll
for (int ii = 0; ii < RANKS_PER_NODE; ++ii) {
// use round-robin gathering from other ranks
size_t offset_rank = ranks[ii] * params.elts_per_rank + local_offset;
if (offset_rank >= params.elts_total) {
continue;
}
vec_t<T, VEC_SIZE> sums, residual_vec, bias_vec;
if constexpr (Bias) {
bias_vec.load(reinterpret_cast<T const*>(params.fusion_params.bias_buffer) +
offset_rank % params.fusion_params.hidden_size);
}
if constexpr (Residual) {
residual_vec.load(reinterpret_cast<T const*>(params.fusion_params.residual_buffer) +
offset_rank);
}
if constexpr (PUSH_MODE) {
*reinterpret_cast<int4*>(&local_output_buffer[offset_rank]) =
*reinterpret_cast<int4*>(&buffers[ii][local_offset]);
sums.load(&buffers[ii][local_offset]);
} else {
*reinterpret_cast<int4*>(&local_output_buffer[offset_rank]) =
*reinterpret_cast<int4*>(&buffers[ii][offset_rank]);
sums.load(&buffers[ii][offset_rank]);
}
if constexpr (Bias) {
sums = vec_add<T, VEC_SIZE>(sums, bias_vec);
}
if constexpr (Residual) {
sums = vec_add<T, VEC_SIZE>(sums, residual_vec);
}
sums.store(&local_output_buffer[offset_rank]);
}
}
#if (defined(__CUDA_ARCH__) && (__CUDA_ARCH__ >= 900) && (__CUDA_ARCH__ < 1200))
cudaTriggerProgrammaticLaunchCompletion();
#endif
}
template <typename T>
bool configurationSupported(AllReduceStrategyType algo, size_t msg_size, size_t n_ranks) {
size_t elts_per_thread = 16 / sizeof(T);
int const msg_align =
(algo == AllReduceStrategyType::TWOSHOT) ? n_ranks * elts_per_thread : elts_per_thread;
bool supported_algo =
(algo == AllReduceStrategyType::ONESHOT || algo == AllReduceStrategyType::TWOSHOT);
return supported_algo && (msg_size % msg_align == 0);
}
template <typename T>
std::tuple<int, int> kernelLaunchConfig(AllReduceStrategyType algo, AllReduceParams<T>& params,
size_t elts_per_thread) {
int blocks_per_grid = 1, threads_per_block = DEFAULT_BLOCK_SIZE;
switch (algo) {
case AllReduceStrategyType::ONESHOT: {
FLASHINFER_CHECK(params.elts_total % elts_per_thread == 0,
"hidden_size must be a multiple of ", elts_per_thread);
size_t const total_threads = round_up(params.elts_total / elts_per_thread, WARP_SIZE);
threads_per_block = std::min(DEFAULT_BLOCK_SIZE, total_threads);
blocks_per_grid = std::min(static_cast<size_t>(MAX_ALL_REDUCE_BLOCKS),
ceil_div(total_threads, threads_per_block));
params.elts_per_block =
round_up(ceil_div(params.elts_total, blocks_per_grid), elts_per_thread);
break;
}
case AllReduceStrategyType::TWOSHOT: {
FLASHINFER_CHECK(params.elts_total % (elts_per_thread * params.ranks_per_node) == 0,
"hidden_size must be a multiple of ",
elts_per_thread * params.ranks_per_node);
size_t const total_threads =
round_up(params.elts_total / (elts_per_thread * params.ranks_per_node), WARP_SIZE);
/*
threads_per_block = std::min(DEFAULT_BLOCK_SIZE, total_threads);
blocks_per_grid = std::min(static_cast<size_t>(MAX_ALL_REDUCE_BLOCKS), ceil_div(total_threads,
threads_per_block));
*/
while (total_threads % blocks_per_grid != 0 ||
total_threads / blocks_per_grid > DEFAULT_BLOCK_SIZE) {
blocks_per_grid += 1;
}
threads_per_block = total_threads / blocks_per_grid;
// NOTE: need to adjust here
if (blocks_per_grid > MAX_ALL_REDUCE_BLOCKS) {
size_t iter_factor = 1;
while (blocks_per_grid / iter_factor > MAX_ALL_REDUCE_BLOCKS ||
blocks_per_grid % iter_factor) {
iter_factor += 1;
}
blocks_per_grid /= iter_factor;
}
params.elts_per_rank = params.elts_total / params.ranks_per_node;
params.rank_offset = params.local_rank * params.elts_per_rank;
params.elts_per_block =
round_up(ceil_div(params.elts_per_rank, blocks_per_grid), elts_per_thread);
break;
}
default:
FLASHINFER_ERROR("Algorithm not supported here.");
}
return std::make_tuple(blocks_per_grid, threads_per_block);
}
template <typename T, int RANKS_PER_NODE, bool PUSH_MODE = false, bool USE_MEMCPY = false,
bool Bias = false, bool Affine = false>
cudaError_t AllReduceNormKernelLaunch(AllReduceStrategyType algo, AllReduceFusionOp fusionOp,
AllReduceParams<T>& params, bool launch_with_pdl,
cudaStream_t stream) {
FLASHINFER_CHECK((fusionOp == AllReduceFusionOp::RESIDUAL_RMS_NORM ||
fusionOp == AllReduceFusionOp::RESIDUAL_RMS_PREPOST_NORM),
"Unsupported AllReduceFusionOp: %d", static_cast<int>(fusionOp));
if (algo == AllReduceStrategyType::ONESHOT) {
return reduce_fusion::one_shot_all_reduce_norm_kernel_launcher<T, RANKS_PER_NODE, Bias, Affine>(
params, fusionOp, launch_with_pdl, stream);
} else {
FLASHINFER_CHECK(!(USE_MEMCPY && PUSH_MODE), "Memcpy cannot be used with PUSH_MODE.");
size_t elts_per_thread = 16 / sizeof(T);
auto [blocks_per_grid, threads_per_block] =
kernelLaunchConfig<T>(algo, params, elts_per_thread);
if (USE_MEMCPY) {
cudaMemcpyAsync(params.peer_comm_buffer_ptrs[params.local_rank],
params.local_input_buffer_ptr, params.elts_total * sizeof(T),
cudaMemcpyDeviceToDevice, stream);
}
auto output_ptr = params.local_output_buffer_ptr;
params.local_output_buffer_ptr = params.fusion_params.intermediate_buffer;
cudaLaunchConfig_t kernelConfig = {0};
kernelConfig.gridDim = blocks_per_grid;
kernelConfig.blockDim = threads_per_block;
kernelConfig.dynamicSmemBytes = 0;
kernelConfig.stream = stream;
cudaLaunchAttribute attribute[1];
attribute[0].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[0].val.programmaticStreamSerializationAllowed = launch_with_pdl;
kernelConfig.attrs = attribute;
kernelConfig.numAttrs = 1;
FLASHINFER_CUDA_CALL(cudaLaunchKernelEx(
&kernelConfig,
twoShotAllReduceKernel<T, RANKS_PER_NODE, !USE_MEMCPY, PUSH_MODE, Bias, true>, params));
params.local_output_buffer_ptr = output_ptr;
return reduce_fusion::rms_norm_kernel_launcher<T, false, false, Affine>(
params, fusionOp, launch_with_pdl, stream);
}
return cudaSuccess;
}
template <typename T, int RANKS_PER_NODE, bool PUSH_MODE = false, bool USE_MEMCPY = false>
cudaError_t AllReduceNormDispatch(AllReduceStrategyType algo, AllReduceFusionOp fusionOp,
AllReduceParams<T>& params, bool launch_with_pdl,
cudaStream_t stream) {
if (params.fusion_params.bias_buffer && params.fusion_params.weight_buffer) {
return AllReduceNormKernelLaunch<T, RANKS_PER_NODE, PUSH_MODE, USE_MEMCPY, true, true>(
algo, fusionOp, params, launch_with_pdl, stream);
} else if (params.fusion_params.bias_buffer && !params.fusion_params.weight_buffer) {
return AllReduceNormKernelLaunch<T, RANKS_PER_NODE, PUSH_MODE, USE_MEMCPY, true, false>(
algo, fusionOp, params, launch_with_pdl, stream);
} else if (!params.fusion_params.bias_buffer && params.fusion_params.weight_buffer) {
return AllReduceNormKernelLaunch<T, RANKS_PER_NODE, PUSH_MODE, USE_MEMCPY, false, true>(
algo, fusionOp, params, launch_with_pdl, stream);
} else {
return AllReduceNormKernelLaunch<T, RANKS_PER_NODE, PUSH_MODE, USE_MEMCPY, false, false>(
algo, fusionOp, params, launch_with_pdl, stream);
}
return cudaSuccess;
}
template <typename T, int RANKS_PER_NODE, bool PUSH_MODE = false, bool USE_MEMCPY = false>
cudaError_t AllReduceDispatch(AllReduceStrategyType algo, AllReduceFusionOp fusionOp,
AllReduceParams<T>& params, bool launch_with_pdl,
cudaStream_t stream) {
FLASHINFER_CHECK(fusionOp == AllReduceFusionOp::NONE, "Unsupported AllReduceFusionOp: %d",
static_cast<int>(fusionOp));
FLASHINFER_CHECK(!(USE_MEMCPY && PUSH_MODE), "Memcpy cannot be used with PUSH_MODE.");
size_t elts_per_thread = 16 / sizeof(T);
auto [blocks_per_grid, threads_per_block] = kernelLaunchConfig(algo, params, elts_per_thread);
if (USE_MEMCPY) {
cudaMemcpyAsync(params.peer_comm_buffer_ptrs[params.local_rank], params.local_input_buffer_ptr,
params.elts_total * sizeof(T), cudaMemcpyDeviceToDevice, stream);
}
if (algo == AllReduceStrategyType::ONESHOT) {
auto* kernel_instance = &oneShotAllReduceKernel<T, RANKS_PER_NODE, !USE_MEMCPY, PUSH_MODE>;
cudaLaunchConfig_t config;
config.gridDim = blocks_per_grid;
config.blockDim = threads_per_block;
config.dynamicSmemBytes = 0;
config.stream = stream;
cudaLaunchAttribute attribute[1];
attribute[0].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[0].val.programmaticStreamSerializationAllowed = launch_with_pdl;
config.attrs = attribute;
config.numAttrs = 1;
cudaLaunchKernelEx(&config, kernel_instance, params);
} else {
auto* kernel_instance = &twoShotAllReduceKernel<T, RANKS_PER_NODE, !USE_MEMCPY, PUSH_MODE>;
cudaLaunchConfig_t config;
config.gridDim = blocks_per_grid;
config.blockDim = threads_per_block;
config.dynamicSmemBytes = 0;
config.stream = stream;
cudaLaunchAttribute attribute[1];
attribute[0].id = cudaLaunchAttributeProgrammaticStreamSerialization;
attribute[0].val.programmaticStreamSerializationAllowed = launch_with_pdl;
config.attrs = attribute;
config.numAttrs = 1;
cudaLaunchKernelEx(&config, kernel_instance, params);
}
return cudaSuccess;
}
template <typename T, int RANKS_PER_NODE, bool PUSH_MODE = false, bool USE_MEMCPY = false>
cudaError_t AllReduceDispatchMemcpy(AllReduceStrategyType algo, AllReduceFusionOp fusionOp,
AllReduceParams<T>& params, bool launch_with_pdl,
cudaStream_t stream) {
if (fusionOp == AllReduceFusionOp::NONE) {
FLASHINFER_LOG_DEBUG("AllReduceDispatch enabled");
return AllReduceDispatch<T, RANKS_PER_NODE, PUSH_MODE, USE_MEMCPY>(algo, fusionOp, params,
launch_with_pdl, stream);
} else {
FLASHINFER_LOG_DEBUG("AllReduceNormDispatch enabled");
return AllReduceNormDispatch<T, RANKS_PER_NODE, PUSH_MODE, USE_MEMCPY>(algo, fusionOp, params,
launch_with_pdl, stream);
}
}
template <typename T, int RANKS_PER_NODE, bool PUSH_MODE = false>
cudaError_t AllReduceDispatchPushMode(AllReduceStrategyType algo, AllReduceStrategyConfig config,
AllReduceFusionOp fusionOp, AllReduceParams<T>& params,
bool launch_with_pdl, cudaStream_t stream) {
if (static_cast<std::underlying_type_t<AllReduceStrategyConfig>>(config) &
static_cast<std::underlying_type_t<AllReduceStrategyConfig>>(
AllReduceStrategyConfig::USE_MEMCPY)) {
return AllReduceDispatchMemcpy<T, RANKS_PER_NODE, PUSH_MODE, true>(algo, fusionOp, params,
launch_with_pdl, stream);
} else {
return AllReduceDispatchMemcpy<T, RANKS_PER_NODE, PUSH_MODE, false>(algo, fusionOp, params,
launch_with_pdl, stream);
}
}
template <typename T, int RANKS_PER_NODE> //, bool USE_MEMCPY = false, bool PUSH_MODE = false>
cudaError_t AllReduceDispatchRanksPerNode(AllReduceStrategyType algo,
AllReduceStrategyConfig config,
AllReduceFusionOp fusionOp, AllReduceParams<T>& params,
bool launch_with_pdl, cudaStream_t stream) {
if (static_cast<std::underlying_type_t<AllReduceStrategyConfig>>(config) &
static_cast<std::underlying_type_t<AllReduceStrategyConfig>>(
AllReduceStrategyConfig::PUSH_MODE)) {
return AllReduceDispatchPushMode<T, RANKS_PER_NODE, true>(algo, config, fusionOp, params,
launch_with_pdl, stream);
} else {
return AllReduceDispatchPushMode<T, RANKS_PER_NODE, false>(algo, config, fusionOp, params,
launch_with_pdl, stream);
}
}
template <typename T>
cudaError_t AllReduceDispatchType(AllReduceParams<T>& params, AllReduceStrategyType strat,
AllReduceStrategyConfig config, AllReduceFusionOp fusionOp,
bool launch_with_pdl, cudaStream_t stream) {
switch (params.ranks_per_node) {
case 2:
return AllReduceDispatchRanksPerNode<T, /*RANKS_PER_NODE=*/2>(strat, config, fusionOp, params,
launch_with_pdl, stream);
case 4:
return AllReduceDispatchRanksPerNode<T, 4>(strat, config, fusionOp, params, launch_with_pdl,
stream);
case 6:
return AllReduceDispatchRanksPerNode<T, 6>(strat, config, fusionOp, params, launch_with_pdl,
stream);
case 8:
return AllReduceDispatchRanksPerNode<T, 8>(strat, config, fusionOp, params, launch_with_pdl,
stream);
case 16:
return AllReduceDispatchRanksPerNode<T, 16>(strat, config, fusionOp, params, launch_with_pdl,
stream);
default:
FLASHINFER_ERROR("Custom all reduce only supported on {2, 4, 6, 8, 16} GPUs per node.");
}
return cudaSuccess;
}
template <typename T>
cudaError_t customAllReduce(AllReduceParams<T>& params, AllReduceStrategyType strat,
AllReduceStrategyConfig config, AllReduceFusionOp fusionOp,
bool launch_with_pdl, cudaStream_t stream) {
FLASHINFER_CHECK(configurationSupported<T>(strat, params.elts_total, params.ranks_per_node),
"Custom all-reduce configuration unsupported");
return AllReduceDispatchType<T>(params, strat, config, fusionOp, launch_with_pdl, stream);
}
template <typename T>
cudaError_t lamportInitialize(void* buffer, size_t size, cudaStream_t stream) {
if (size == 0) {
return cudaSuccess;
}
FLASHINFER_LOG_INFO("lamportInitialize start: buffer: {}, size: {}", buffer, size);
return reduce_fusion::lamport_initialize_kernel_launcher<T>(buffer, size, stream);
}
// lamport: 3 buffers for synchronization
template <typename T>
cudaError_t lamportInitializeAll(void* buffer_0, void* buffer_1, void* buffer_2, size_t size,
cudaStream_t stream) {
auto status = lamportInitialize<T>(buffer_0, size / sizeof(T), stream);
FLASHINFER_CHECK(status == cudaSuccess, "lamportInitialize failed with error code " +
std::string(cudaGetErrorString(status)));
status = lamportInitialize<T>(buffer_1, size / sizeof(T), stream);
FLASHINFER_CHECK(status == cudaSuccess, "lamportInitialize failed with error code " +
std::string(cudaGetErrorString(status)));
status = lamportInitialize<T>(buffer_2, size / sizeof(T), stream);
FLASHINFER_CHECK(status == cudaSuccess, "lamportInitialize failed with error code " +
std::string(cudaGetErrorString(status)));
cudaDeviceSynchronize();
return cudaSuccess;
}
} // namespace trtllm_allreduce
} // namespace flashinfer