ColossalAI/extensions/csrc/kernel/cuda/context_kv_cache_memcpy_ker...

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#include <ATen/cuda/CUDAContext.h>
#include <torch/extension.h>
#include "utils/vec_copy.h"
#include "common/micros.h"
using colossalAI::cuda::utils::get_vec_size;
using colossalAI::cuda::utils::copy;
using colossalAI::funcs::CastFunctor;
template<typename T, typename CacheT, bool Aligned, int VecSize>
__global__ void context_kv_cache_memcpy_kernel(
const T* __restrict__ key,
const T* __restrict__ value,
CacheT* __restrict__ key_cache,
CacheT* __restrict__ value_cache,
const int* __restrict__ sequence_lengths,
const int* __restrict__ cu_seqlens,
const int* __restrict__ block_tables,
const int head_num,
const int head_dim,
const int block_size,
const int batch_size,
const int block_table_stride,
const int64_t key_stride,
const int64_t value_stride,
const int x
)
{
const int seq_token_id = blockIdx.x;
const int seq_id = blockIdx.y;
const int block_id = block_tables[seq_id * block_table_stride + seq_token_id / block_size];
if (block_id < 0 || seq_token_id > sequence_lengths[seq_id] - 1) {
return ;
}
const int block_offset = seq_token_id % block_size;
const int hidden_size = head_num * head_dim;
const int total_token_id = cu_seqlens[seq_id] + seq_token_id;
int head_id;
int head_offset;
int x_id;
int x_offset;
int64_t key_src_id;
int64_t value_src_id;
int64_t target_key_id;
int64_t target_value_id;
int i = threadIdx.x * VecSize;
for (; i <= (hidden_size - VecSize); i += blockDim.x * VecSize) {
head_id = i / head_dim;
head_offset = i % head_dim;
x_id = head_offset / x;
x_offset = head_offset % x;
key_src_id = total_token_id * key_stride + i;
value_src_id = total_token_id * value_stride + i;
target_key_id = block_id * hidden_size * block_size
+ head_id * block_size * head_dim
+ x_id * block_size * x
+ block_offset * x
+ x_offset;
target_value_id = block_id * hidden_size * block_size
+ head_id * block_size * head_dim
+ block_offset * head_dim + head_offset;
copy<T, CacheT, VecSize>(key + key_src_id, key_cache + target_key_id);
copy<T, CacheT, VecSize>(value + value_src_id, value_cache + target_value_id);
}
// tail process
if (!Aligned) {
for (; i < hidden_size; ++i ) {
head_id = i / head_dim;
head_offset = i % head_dim;
x_id = head_offset / x;
x_offset = head_offset % x;
key_src_id = total_token_id * key_stride + i;
value_src_id = total_token_id * value_stride + i;
target_key_id = block_id * hidden_size * block_size
+ head_id * block_size * head_dim
+ x_id * block_size * x
+ block_offset * x
+ x_offset;
target_value_id = block_id * hidden_size * block_size
+ head_id * block_size * head_dim
+ block_offset * head_dim + head_offset;
key_cache[target_key_id] = CastFunctor<T, CacheT>()(key[key_src_id]);
value_cache[target_value_id] = CastFunctor<T, CacheT>()(value[value_src_id]);
}
}
}
template<typename T, typename CacheT>
void apply_context_kv_cache_memcpy(
torch::Tensor& key, // [num_tokens, head_num, head_dim]
torch::Tensor& value, // [num_tokens, head_num, head_dim]
torch::Tensor& key_cache, // [num_blocks, head_num, head_dim/x, block_size, x]
torch::Tensor& value_cache, // [num_blocks, head_num, block_size, head_dim]
torch::Tensor& sequence_lengths, // [batch_size]
torch::Tensor& cu_seqlens, // [batch_size + 1]
torch::Tensor& block_tables, // [batch_size, max_seq_len]
int max_seq_len_in_batch)
{
int num_tokens = key.size(0);
int head_num = key.size(1);
int head_dim = key.size(2);
int block_size = key_cache.size(3);
int x = key_cache.size(4);
int batch_size = block_tables.size(0);
int64_t key_stride = key.stride(0);
int64_t value_stride = value.stride(0);
int block_table_stride = block_tables.stride(0);
int vec_size = get_vec_size<T>(key);
bool aligned = true;
if (head_dim % vec_size != 0) {
aligned = false;
}
int thread_nums = head_num * head_dim / vec_size;
const cudaStream_t stream = at::cuda::getCurrentCUDAStream();
dim3 grid(max_seq_len_in_batch, batch_size);
dim3 block(std::min(thread_nums, 512));
#define CONTEXT_KV_CACHE_MEMCOPY_KERNEL_LAUNCH(__aligned, __vec_size) \
do { \
context_kv_cache_memcpy_kernel<T, CacheT, __aligned, __vec_size><<<grid, block, 0, stream>>>( \
reinterpret_cast<T*>(key.data_ptr()), \
reinterpret_cast<T*>(value.data_ptr()), \
reinterpret_cast<CacheT*>(key_cache.data_ptr()), \
reinterpret_cast<CacheT*>(value_cache.data_ptr()), \
sequence_lengths.data_ptr<int>(), \
cu_seqlens.data_ptr<int>(), \
block_tables.data_ptr<int>(), \
head_num, \
head_dim, \
block_size, \
batch_size, \
block_table_stride, \
key_stride, \
value_stride, \
x \
); \
} while(0)
#define CONTEXT_KV_CACHE_MEMCOPY_KERNEL_LAUNCH_VEC_SIZE_CASE(__aligned) \
do { \
switch (vec_size) { \
case 1: \
CONTEXT_KV_CACHE_MEMCOPY_KERNEL_LAUNCH(__aligned, 1); \
break; \
case 2: \
CONTEXT_KV_CACHE_MEMCOPY_KERNEL_LAUNCH(__aligned, 2); \
break; \
case 4: \
CONTEXT_KV_CACHE_MEMCOPY_KERNEL_LAUNCH(__aligned, 4); \
break; \
default: \
AT_ERROR("Unsupported vectorized size ", vec_size); \
break; \
} \
} while(0)
if (aligned) {
CONTEXT_KV_CACHE_MEMCOPY_KERNEL_LAUNCH_VEC_SIZE_CASE(true);
}
else {
CONTEXT_KV_CACHE_MEMCOPY_KERNEL_LAUNCH_VEC_SIZE_CASE(false);
}
AT_CUDA_CHECK(cudaGetLastError());
}
void context_kv_cache_memcpy(
torch::Tensor& key, // [num_tokens, head_num, head_dim]
torch::Tensor& value, // [num_tokens, head_num, head_dim]
torch::Tensor& key_cache, // [num_blocks, head_num, head_dim/x, block_size, x]
torch::Tensor& value_cache, // [num_blocks, head_num, block_size, head_dim]
torch::Tensor& sequence_lengths, // [batch_size]
torch::Tensor& cu_seqlens, // [batch_size + 1]
torch::Tensor& block_tables, // [batch_size, max_seq_len]
int max_seq_len_in_batch)
{
#define _(T, CacheT) \
apply_context_kv_cache_memcpy<T, CacheT>( \
key, \
value, \
key_cache, \
value_cache, \
sequence_lengths, \
cu_seqlens, \
block_tables, \
max_seq_len_in_batch \
)
if(key_cache.scalar_type() == at::ScalarType::Byte)
{
switch (key.scalar_type())
{
case at::ScalarType::Float:
_(float, uint8_t);
break;
case at::ScalarType::Half:
_(half, uint8_t);
break;
case at::ScalarType::BFloat16:
_(__nv_bfloat16, uint8_t);
break;
}
}
else
{
switch (key.scalar_type())
{
case at::ScalarType::Float:
_(float, float);
break;
case at::ScalarType::Half:
_(half, half);
break;
case at::ScalarType::BFloat16:
_(__nv_bfloat16, __nv_bfloat16);
break;
}
}
#undef _
}