Files
enginex-mthreads-vllm/vllm/v1/worker/gpu/block_table.py
2026-01-19 10:38:50 +08:00

315 lines
12 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from collections.abc import Iterable
import torch
from vllm.attention.backends.utils import PAD_SLOT_ID
from vllm.triton_utils import tl, triton
from vllm.utils.math_utils import cdiv
from vllm.v1.utils import CpuGpuBuffer
class BlockTables:
def __init__(
self,
block_sizes: list[int],
max_num_reqs: int,
max_num_batched_tokens: int,
max_model_len: int,
device: torch.device,
pin_memory: bool,
):
self.block_sizes = block_sizes
self.max_num_reqs = max_num_reqs
self.max_num_batched_tokens = max_num_batched_tokens
self.max_model_len = max_model_len
self.device = device
self.pin_memory = pin_memory
self.num_kv_cache_groups = len(self.block_sizes)
# num_kv_cache_groups x [max_num_reqs, max_num_blocks]
self.block_tables: list[torch.Tensor] = []
for i in range(self.num_kv_cache_groups):
block_size = self.block_sizes[i]
max_num_blocks = cdiv(self.max_model_len, block_size)
block_table = torch.zeros(
self.max_num_reqs,
max_num_blocks,
dtype=torch.int32,
device=self.device,
)
self.block_tables.append(block_table)
self.block_table_ptrs = self._make_ptr_tensor(self.block_tables)
# Block tables used for model's forward pass.
# num_kv_cache_groups x [max_num_reqs, max_num_blocks]
self.input_block_tables: list[torch.Tensor] = [
torch.zeros_like(block_table) for block_table in self.block_tables
]
self.input_block_table_ptrs = self._make_ptr_tensor(self.input_block_tables)
self.block_table_strides = torch.tensor(
[b.stride(0) for b in self.block_tables],
dtype=torch.int64,
device=self.device,
)
self.block_sizes_tensor = torch.tensor(
self.block_sizes, dtype=torch.int32, device=self.device
)
self.num_blocks = torch.zeros(
self.num_kv_cache_groups,
self.max_num_reqs,
dtype=torch.int32,
device=self.device,
)
self.slot_mappings = torch.zeros(
self.num_kv_cache_groups,
self.max_num_batched_tokens,
dtype=torch.int64,
device=self.device,
)
# Misc buffers.
self.req_indices = self._make_buffer(self.max_num_reqs, dtype=torch.int32)
self.overwrite = self._make_buffer(self.max_num_reqs, dtype=torch.bool)
self.cu_num_new_blocks = self._make_buffer(
self.num_kv_cache_groups, self.max_num_reqs + 1, dtype=torch.int32
)
def _make_buffer(self, *args, dtype: torch.dtype) -> CpuGpuBuffer:
return CpuGpuBuffer(
*args, dtype=dtype, pin_memory=self.pin_memory, device=self.device
)
def _make_ptr_tensor(self, x: Iterable[torch.Tensor]) -> torch.Tensor:
# NOTE(woosuk): Use uint64 instead of int64 to cover all possible addresses.
ptrs_tensor_cpu = torch.tensor(
[t.data_ptr() for t in x],
dtype=torch.uint64,
device="cpu",
pin_memory=self.pin_memory,
)
return ptrs_tensor_cpu.to(self.device, non_blocking=True)
def append_block_ids(
self,
# [num_reqs]
req_indices: list[int],
# [num_kv_cache_groups, num_reqs + 1]
cu_num_new_blocks: tuple[list[int], ...],
# [num_kv_cache_groups, num_new_blocks]
new_block_ids: tuple[list[int], ...],
# [num_reqs]
overwrite: list[bool],
) -> None:
num_reqs = len(req_indices)
self.req_indices.np[:num_reqs] = req_indices
self.overwrite.np[:num_reqs] = overwrite
for i in range(self.num_kv_cache_groups):
self.cu_num_new_blocks.np[i, : num_reqs + 1] = cu_num_new_blocks[i]
# NOTE(woosuk): Here, we cannot use a fixed-size buffer because there's
# no clear upper bound to the number of new blocks in a single step.
# NOTE(woosuk): The buffer has to be cached, because otherwise we cannot
# guarantee that the buffer is not freed before the copy is completed.
self.new_block_ids_cpu = torch.empty(
self.num_kv_cache_groups,
max(len(x) for x in new_block_ids),
dtype=torch.int32,
device="cpu",
pin_memory=self.pin_memory,
)
new_block_ids_np = self.new_block_ids_cpu.numpy()
for i in range(self.num_kv_cache_groups):
new_block_ids_np[i, : len(new_block_ids[i])] = new_block_ids[i]
new_block_ids_gpu = self.new_block_ids_cpu.to(self.device, non_blocking=True)
_append_block_ids_kernel[(self.num_kv_cache_groups, num_reqs)](
self.req_indices.copy_to_gpu(num_reqs),
self.cu_num_new_blocks.copy_to_gpu(),
self.cu_num_new_blocks.gpu.stride(0),
new_block_ids_gpu,
new_block_ids_gpu.stride(0),
self.overwrite.copy_to_gpu(num_reqs),
self.block_table_strides,
self.block_table_ptrs,
self.num_blocks,
self.num_blocks.stride(0),
BLOCK_SIZE=1024, # type: ignore
)
def gather_block_tables(
self,
idx_mapping: torch.Tensor,
) -> tuple[torch.Tensor, ...]:
num_reqs = idx_mapping.shape[0]
_gather_block_tables_kernel[(self.num_kv_cache_groups, num_reqs)](
idx_mapping,
self.block_table_ptrs,
self.input_block_table_ptrs,
self.block_table_strides,
self.num_blocks,
self.num_blocks.stride(0),
BLOCK_SIZE=1024, # type: ignore
)
return tuple(block_table[:num_reqs] for block_table in self.input_block_tables)
def get_dummy_block_tables(self, num_reqs: int) -> tuple[torch.Tensor, ...]:
return tuple(block_table[:num_reqs] for block_table in self.input_block_tables)
def compute_slot_mappings(
self,
query_start_loc: torch.Tensor,
positions: torch.Tensor,
) -> torch.Tensor:
num_reqs = query_start_loc.shape[0] - 1
num_tokens = positions.shape[0]
num_groups = self.num_kv_cache_groups
_compute_slot_mappings_kernel[(num_groups, num_reqs + 1)](
num_tokens,
self.max_num_batched_tokens,
query_start_loc,
positions,
self.input_block_table_ptrs,
self.block_table_strides,
self.block_sizes_tensor,
self.slot_mappings,
self.slot_mappings.stride(0),
PAD_ID=PAD_SLOT_ID,
BLOCK_SIZE=1024, # type: ignore
)
return self.slot_mappings[:, :num_tokens]
def get_dummy_slot_mappings(self, num_tokens: int) -> torch.Tensor:
self.slot_mappings.fill_(PAD_SLOT_ID)
return self.slot_mappings[:, :num_tokens]
@triton.jit
def _append_block_ids_kernel(
# Inputs
req_indices, # [num_reqs]
cu_num_new_blocks_ptr, # [num_kv_cache_groups, num_reqs + 1]
cu_num_new_blocks_stride,
new_block_ids_ptr, # [num_kv_cache_groups, num_new_blocks]
new_block_ids_stride,
overwrite, # [num_reqs]
block_table_strides, # [num_kv_cache_groups]
# Outputs
block_table_ptrs, # [num_kv_cache_groups]
num_blocks_ptr, # [num_kv_cache_groups, max_num_reqs]
num_blocks_stride,
# Constants
BLOCK_SIZE: tl.constexpr,
):
group_id = tl.program_id(0)
batch_idx = tl.program_id(1)
req_idx = tl.load(req_indices + batch_idx)
do_overwrite = tl.load(overwrite + batch_idx)
group_new_blocks_ptr = cu_num_new_blocks_ptr + group_id * cu_num_new_blocks_stride
start_idx = tl.load(group_new_blocks_ptr + batch_idx)
end_idx = tl.load(group_new_blocks_ptr + batch_idx + 1)
num_new_blocks = end_idx - start_idx
group_num_blocks_ptr = num_blocks_ptr + group_id * num_blocks_stride
dst_start_idx = tl.load(group_num_blocks_ptr + req_idx) if not do_overwrite else 0
dst_end_idx = dst_start_idx + num_new_blocks
tl.store(group_num_blocks_ptr + req_idx, dst_end_idx)
# Destination
block_table_ptr = _load_ptr(block_table_ptrs + group_id, tl.int32)
block_table_stride = tl.load(block_table_strides + group_id)
row_ptr = block_table_ptr + req_idx * block_table_stride
group_new_block_ids_ptr = new_block_ids_ptr + group_id * new_block_ids_stride
for i in range(0, num_new_blocks, BLOCK_SIZE):
offset = i + tl.arange(0, BLOCK_SIZE)
block_ids = tl.load(
group_new_block_ids_ptr + start_idx + offset, mask=offset < num_new_blocks
)
tl.store(
row_ptr + dst_start_idx + offset, block_ids, mask=offset < num_new_blocks
)
@triton.jit
def _gather_block_tables_kernel(
batch_idx_to_req_idx, # [batch_size]
src_block_table_ptrs, # [num_kv_cache_groups]
dst_block_table_ptrs, # [num_kv_cache_groups]
block_table_strides, # [num_kv_cache_groups]
num_blocks_ptr, # [num_kv_cache_groups, max_num_reqs]
num_blocks_stride,
BLOCK_SIZE: tl.constexpr,
):
# kv cache group id
group_id = tl.program_id(0)
batch_idx = tl.program_id(1)
req_idx = tl.load(batch_idx_to_req_idx + batch_idx)
group_num_blocks_ptr = num_blocks_ptr + group_id * num_blocks_stride
num_blocks = tl.load(group_num_blocks_ptr + req_idx)
stride = tl.load(block_table_strides + group_id)
src_block_table_ptr = _load_ptr(src_block_table_ptrs + group_id, tl.int32)
src_row_ptr = src_block_table_ptr + req_idx * stride
dst_block_table_ptr = _load_ptr(dst_block_table_ptrs + group_id, tl.int32)
dst_row_ptr = dst_block_table_ptr + batch_idx * stride
for i in tl.range(0, num_blocks, BLOCK_SIZE):
offset = i + tl.arange(0, BLOCK_SIZE)
block_ids = tl.load(src_row_ptr + offset, mask=offset < num_blocks)
tl.store(dst_row_ptr + offset, block_ids, mask=offset < num_blocks)
@triton.jit
def _compute_slot_mappings_kernel(
num_tokens,
max_num_tokens,
cu_num_tokens, # [num_reqs + 1]
pos, # [num_tokens]
block_table_ptrs, # [num_kv_cache_groups]
block_table_strides, # [num_kv_cache_groups]
page_sizes, # [num_kv_cache_groups]
slot_mappings_ptr, # [num_kv_cache_groups, max_num_tokens]
slot_mappings_stride,
PAD_ID: tl.constexpr,
BLOCK_SIZE: tl.constexpr,
):
# kv cache group id
group_id = tl.program_id(0)
req_idx = tl.program_id(1)
slot_mapping_ptr = slot_mappings_ptr + group_id * slot_mappings_stride
if req_idx == tl.num_programs(1) - 1:
# Pad remaining slots to -1. This is needed for CUDA graphs.
for i in range(num_tokens, max_num_tokens, BLOCK_SIZE):
offset = i + tl.arange(0, BLOCK_SIZE)
tl.store(slot_mapping_ptr + offset, PAD_ID, mask=offset < max_num_tokens)
return
block_table_ptr = _load_ptr(block_table_ptrs + group_id, tl.int32)
block_table_stride = tl.load(block_table_strides + group_id)
page_size = tl.load(page_sizes + group_id)
start_idx = tl.load(cu_num_tokens + req_idx)
end_idx = tl.load(cu_num_tokens + req_idx + 1)
for i in range(start_idx, end_idx, BLOCK_SIZE):
offset = i + tl.arange(0, BLOCK_SIZE)
positions = tl.load(pos + offset, mask=offset < end_idx, other=0)
block_indices = positions // page_size
block_numbers = tl.load(
block_table_ptr + req_idx * block_table_stride + block_indices
)
slot_ids = block_numbers * page_size + positions % page_size
tl.store(slot_mapping_ptr + offset, slot_ids, mask=offset < end_idx)
@triton.jit
def _load_ptr(ptr_to_ptr, elem_dtype):
ptr = tl.load(ptr_to_ptr)
ptr = tl.cast(ptr, tl.pointer_type(elem_dtype))
return tl.multiple_of(ptr, 16)