CUDA: better MoE implementation (#283)

* Make fused MoE reproducible

As a bonus, peak performance at pp2048 with u_batch = 2048 is
~8% better.

* Slightly better

* Also do it for non-fused mul_mat_id

---------

Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>
This commit is contained in:
Kawrakow
2025-03-25 07:47:10 +01:00
committed by GitHub
parent f9307d7907
commit 98a264a2ea

View File

@@ -2164,35 +2164,19 @@ struct mmid_row_mapping {
int32_t i2;
};
static __global__ void k_copy_src1_to_contiguous(const char * __restrict__ src1_original, char * __restrict__ src1_contiguous,
int * __restrict__ cur_src1_row, mmid_row_mapping * __restrict__ row_mapping,
const char * __restrict ids, int64_t i02, size_t ids_nb1, size_t ids_nb0,
int64_t ne11, int64_t ne10,
size_t nb11, size_t nb12) {
int32_t iid1 = blockIdx.x;
int32_t id = blockIdx.y;
static __global__ void k_copy_src_to_contiguous(const char * __restrict__ src_original, char * __restrict__ src_contiguous,
const mmid_row_mapping * __restrict__ row_mapping,
int64_t ne10, int64_t ne11, size_t nb11, size_t nb12) {
int32_t i = blockIdx.x;
const int32_t row_id_i = *(const int32_t *) (ids + iid1*ids_nb1 + id*ids_nb0);
const int32_t i11 = row_mapping[i].i1 % ne11;
const int32_t i12 = row_mapping[i].i2;
if (row_id_i != i02) {
return;
}
float * src_row_contiguous = (float *)(src_contiguous + i*nb11);
const float * src_row_original = (const float *)(src_original + i11*nb11 + i12*nb12);
const int64_t i11 = id % ne11;
const int64_t i12 = iid1;
__shared__ int src1_row;
if (threadIdx.x == 0) {
src1_row = atomicAdd(cur_src1_row, 1);
row_mapping[src1_row] = {id, iid1};
}
__syncthreads();
const float * src1_row_original = (const float *)(src1_original + i11*nb11 + i12*nb12);
float * src1_row_contiguous = (float *)(src1_contiguous + src1_row*nb11);
for (int i = threadIdx.x; i < ne10; i += blockDim.x) {
src1_row_contiguous[i] = src1_row_original[i];
for (int j = threadIdx.x; j < ne10; j += blockDim.x) {
src_row_contiguous[j] = src_row_original[j];
}
}
@@ -2213,6 +2197,51 @@ static __global__ void k_copy_dst_from_contiguous(char * __restrict__ dst_origin
}
}
static inline void prepare_row_mappigs(ggml_backend_cuda_context& ctx, int64_t n_as, int64_t n_ids,
const ggml_tensor * ids, std::vector<int>& moe_counts, std::vector<int>& cum_moe_counts,
ggml_cuda_pool_alloc<mmid_row_mapping>& dev_row_mapping) {
GGML_ASSERT(moe_counts.empty() && cum_moe_counts.empty());
auto stream = ctx.stream();
std::vector<char> ids_host(ggml_nbytes(ids));
const char * ids_dev = (const char *) ids->data;
CUDA_CHECK(cudaMemcpyAsync(ids_host.data(), ids_dev, ggml_nbytes(ids), cudaMemcpyDeviceToHost, stream));
//CUDA_CHECK(cudaStreamSynchronize(stream));
std::vector<mmid_row_mapping> rmapping(ids->ne[1]*n_ids);
moe_counts.resize(n_as, 0);
cum_moe_counts.resize(n_as + 1);
for (int64_t iid1 = 0; iid1 < ids->ne[1]; iid1++) {
for (int64_t id = 0; id < n_ids; id++) {
const int32_t row_id_i = *(const int32_t *) (ids_host.data() + iid1*ids->nb[1] + id*ids->nb[0]);
if (row_id_i >= 0 && row_id_i < n_as) ++moe_counts[row_id_i];
}
}
cum_moe_counts[0] = 0;
for (int i = 0; i < (int)n_as; ++i) {
cum_moe_counts[i+1] = cum_moe_counts[i] + moe_counts[i];
}
dev_row_mapping.alloc(cum_moe_counts[n_as]);
for (int64_t iid1 = 0; iid1 < ids->ne[1]; iid1++) {
for (int64_t id = 0; id < n_ids; id++) {
const int32_t row_id_i = *(const int32_t *) (ids_host.data() + iid1*ids->nb[1] + id*ids->nb[0]);
if (row_id_i >= 0 && row_id_i < n_as) {
rmapping[cum_moe_counts[row_id_i]++] = {(int)id, (int)iid1};
}
}
}
for (int i = 0; i < (int)n_as; ++i) cum_moe_counts[i] -= moe_counts[i];
CUDA_CHECK(cudaMemcpyAsync(dev_row_mapping.get(), rmapping.data(), cum_moe_counts[n_as]*sizeof(mmid_row_mapping), cudaMemcpyHostToDevice, stream));
}
static void ggml_cuda_mul_mat_id(ggml_backend_cuda_context & ctx, ggml_tensor * dst) {
const ggml_tensor * src0 = dst->src[0];
const ggml_tensor * src1 = dst->src[1];
@@ -2273,10 +2302,10 @@ static void ggml_cuda_mul_mat_id(ggml_backend_cuda_context & ctx, ggml_tensor *
const int64_t n_as = ne02;
const int64_t n_ids = ids->ne[0];
std::vector<char> ids_host(ggml_nbytes(ids));
const char * ids_dev = (const char *) ids->data;
CUDA_CHECK(cudaMemcpyAsync(ids_host.data(), ids_dev, ggml_nbytes(ids), cudaMemcpyDeviceToHost, stream));
CUDA_CHECK(cudaStreamSynchronize(stream));
//std::vector<char> ids_host(ggml_nbytes(ids));
//const char * ids_dev = (const char *) ids->data;
//CUDA_CHECK(cudaMemcpyAsync(ids_host.data(), ids_dev, ggml_nbytes(ids), cudaMemcpyDeviceToHost, stream));
//CUDA_CHECK(cudaStreamSynchronize(stream));
ggml_tensor src0_row = *src0;
ggml_tensor src1_row = *src1;
@@ -2303,6 +2332,9 @@ static void ggml_cuda_mul_mat_id(ggml_backend_cuda_context & ctx, ggml_tensor *
dst_row.nb[3] = nb1;
if (ne12 == 1) {
std::vector<char> ids_host(ggml_nbytes(ids));
const char * ids_dev = (const char *) ids->data;
CUDA_CHECK(cudaMemcpyAsync(ids_host.data(), ids_dev, ggml_nbytes(ids), cudaMemcpyDeviceToHost, stream));
for (int64_t iid1 = 0; iid1 < ids->ne[1]; iid1++) {
for (int64_t id = 0; id < n_ids; id++) {
const int32_t i02 = *(const int32_t *) (ids_host.data() + iid1*ids->nb[1] + id*ids->nb[0]);
@@ -2324,6 +2356,11 @@ static void ggml_cuda_mul_mat_id(ggml_backend_cuda_context & ctx, ggml_tensor *
}
}
} else {
ggml_cuda_pool_alloc<mmid_row_mapping> dev_row_mapping(ctx.pool());
std::vector<int> moe_counts, cum_moe_counts;
prepare_row_mappigs(ctx, n_as, n_ids, ids, moe_counts, cum_moe_counts, dev_row_mapping);
ggml_cuda_pool_alloc<char> src1_contiguous(ctx.pool(), sizeof(float)*ggml_nelements(src1));
ggml_cuda_pool_alloc<char> dst_contiguous(ctx.pool(), sizeof(float)*ggml_nelements(dst));
@@ -2331,37 +2368,20 @@ static void ggml_cuda_mul_mat_id(ggml_backend_cuda_context & ctx, ggml_tensor *
dst_row.data = dst_contiguous.get();
for (int64_t i02 = 0; i02 < n_as; i02++) {
int64_t num_src1_rows = 0;
for (int64_t iid1 = 0; iid1 < ids->ne[1]; iid1++) {
for (int64_t id = 0; id < n_ids; id++) {
const int32_t row_id_i = *(const int32_t *) (ids_host.data() + iid1*ids->nb[1] + id*ids->nb[0]);
if (row_id_i != i02) {
continue;
}
num_src1_rows++;
}
}
int64_t num_src1_rows = moe_counts[i02];
if (num_src1_rows == 0) {
continue;
}
ggml_cuda_pool_alloc<int> dev_cur_src1_row(ctx.pool(), 1);
ggml_cuda_pool_alloc<mmid_row_mapping> dev_row_mapping(ctx.pool(), num_src1_rows);
CUDA_CHECK(cudaMemsetAsync(dev_cur_src1_row.get(), 0, sizeof(int), stream));
size_t mapping_offset = cum_moe_counts[i02];
{
dim3 block_dims(std::min((unsigned int)ne10, 768u));
dim3 grid_dims(ids->ne[1], n_ids);
k_copy_src1_to_contiguous<<<grid_dims, block_dims, 0, stream>>>(
src1_original, src1_contiguous.get(),
dev_cur_src1_row.get(), dev_row_mapping.get(),
ids_dev, i02, ids->nb[1], ids->nb[0],
ne11, ne10,
nb11, nb12);
dim3 grid_dims(num_src1_rows);
k_copy_src_to_contiguous<<<grid_dims, block_dims, 0, stream>>>(
src1_original, src1_contiguous.get(), dev_row_mapping.get() + mapping_offset, ne10, ne11, nb11, nb12);
CUDA_CHECK(cudaGetLastError());
}
@@ -2387,7 +2407,7 @@ static void ggml_cuda_mul_mat_id(ggml_backend_cuda_context & ctx, ggml_tensor *
dim3 grid_dims(num_src1_rows);
k_copy_dst_from_contiguous<<<grid_dims, block_dims, 0, stream>>>(
dst_original, dst_contiguous.get(),
dev_row_mapping.get(),
dev_row_mapping.get() + mapping_offset,
ne0,
nb1, nb2);
CUDA_CHECK(cudaGetLastError());
@@ -2642,41 +2662,22 @@ static bool ggml_cuda_up_gate_unary(ggml_backend_cuda_context & ctx, ggml_tensor
bool first = false; //true;
ggml_cuda_pool_alloc<mmid_row_mapping> dev_row_mapping(ctx.pool());
std::vector<int> moe_counts, cum_moe_counts;
prepare_row_mappigs(ctx, n_as, n_ids, ids, moe_counts, cum_moe_counts, dev_row_mapping);
for (int64_t i02 = 0; i02 < n_as; i02++) {
int64_t num_src1_rows = 0;
int64_t num_src1_rows = moe_counts[i02];
for (int64_t iid1 = 0; iid1 < ids->ne[1]; iid1++) {
for (int64_t id = 0; id < n_ids; id++) {
const int32_t row_id_i = *(const int32_t *) (ids_host.data() + iid1*ids->nb[1] + id*ids->nb[0]);
if (row_id_i < 0 || row_id_i >= n_as) continue;
//GGML_ASSERT(row_id_i >= 0 && row_id_i < n_as);
if (row_id_i != i02) {
continue;
}
num_src1_rows++;
}
}
if (num_src1_rows == 0) {
continue;
}
ggml_cuda_pool_alloc<int> dev_cur_src1_row(ctx.pool(), 1);
ggml_cuda_pool_alloc<mmid_row_mapping> dev_row_mapping(ctx.pool(), num_src1_rows);
CUDA_CHECK(cudaMemsetAsync(dev_cur_src1_row.get(), 0, sizeof(int), stream));
if (num_src1_rows == 0) continue;
size_t mapping_offset = cum_moe_counts[i02];
{
dim3 block_dims(std::min((unsigned int)ne10, 768u));
dim3 grid_dims(ids->ne[1], n_ids);
k_copy_src1_to_contiguous<<<grid_dims, block_dims, 0, stream>>>(
src1_original, src1_contiguous.get(),
dev_cur_src1_row.get(), dev_row_mapping.get(),
ids_dev, i02, ids->nb[1], ids->nb[0],
ne11, ne10,
nb11, nb12);
dim3 grid_dims(num_src1_rows);
k_copy_src_to_contiguous<<<grid_dims, block_dims, 0, stream>>>(
src1_original, src1_contiguous.get(), dev_row_mapping.get() + mapping_offset, ne10, ne11, nb11, nb12);
CUDA_CHECK(cudaGetLastError());
}
@@ -2733,7 +2734,7 @@ static bool ggml_cuda_up_gate_unary(ggml_backend_cuda_context & ctx, ggml_tensor
dim3 grid_dims(num_src1_rows);
k_copy_dst_from_contiguous<<<grid_dims, block_dims, 0, stream>>>(
(char *)next->data, final_dst_contiguous.get(),
dev_row_mapping.get(),
dev_row_mapping.get() + mapping_offset,
next->ne[0],
next->nb[1], next->nb[2]);
CUDA_CHECK(cudaGetLastError());
@@ -2745,7 +2746,7 @@ static bool ggml_cuda_up_gate_unary(ggml_backend_cuda_context & ctx, ggml_tensor
dim3 grid_dims(num_src1_rows);
k_copy_dst_from_contiguous<<<grid_dims, block_dims, 0, stream>>>(
dst_original, dst_gate_contiguous.get(),
dev_row_mapping.get(),
dev_row_mapping.get() + mapping_offset,
ne0,
nb1, nb2);
CUDA_CHECK(cudaGetLastError());