feat: import CUDA kernels from xllm/CCCL/FLA upstream repos

Sources cloned and tree'd (no --depth):
  - jd-opensource/xllm: ILU kernels, CUDA kernels, MoE kernels
  - NVIDIA/cccl: CUB tuning/dispatch headers (block-level primitives)
  - fla-org/flash-linear-attention: Triton GDN kernels
  - NVIDIA/cutlass: grouped GEMM reference (read, not copied)
  - Dao-AILab/flash-attention: attention kernel reference (SM80+, read only)

New CUDA kernels (from xllm, SM-agnostic, portable to BI-V100):
  ex_engine/xllm_kernels/cuda/activation.cu    (188 lines) — silu_and_mul, gelu
  ex_engine/xllm_kernels/cuda/norm.cu          (600 lines) — rms_norm, fused_add_rms_norm
  ex_engine/xllm_kernels/cuda/rope.cu          (258 lines) — rotary_embedding
  ex_engine/xllm_kernels/cuda/block_copy.cu    (209 lines) — copy_blocks, swap_blocks
  ex_engine/xllm_kernels/cuda/reshape_paged_cache.cu (101 lines) — KV cache ops
  ex_engine/xllm_kernels/cuda/headers/         (5 headers for compilation)

ILU bridge kernel sources (from xllm, verified SAME as upstream):
  ex_engine/xllm_kernels/ilu/    (10 files, 925 lines total)
  — activation.cpp, attention.cpp, fused_moe.cpp, group_gemm.cpp,
    matmul.cpp, norm.cpp, rope.cpp, ilu_ops_api.h, ixformer.h, utils.h

FLA Triton GDN kernels (for GatedDeltaNet without SM90+ FlashQLA):
  ex_engine/fla_kernels/gated_delta_rule/  (7 files, 2370 lines)
  — chunk_fwd.py (428), chunk.py (487), wy_fast.py (409),
    fused_recurrent.py (392), naive.py (161), gate.py (380)

CCCL sync (12 tuning + 14 dispatch headers updated from NVIDIA/cccl):
  cccl_upstream/cub/cub/device/dispatch/tuning/ — 12 changed files synced
  cccl_upstream/cub/cub/device/dispatch/ — 14 changed dispatch files synced

Compilation targets for real machine (ivcore10):
  1. CUDA kernels: --cuda-gpu-arch=ivcore10 via corex clang/16
  2. ILU bridges: torch.utils.cpp_extension linking ixformer .so
  3. FLA kernels: Triton JIT (if Triton works on BI-V100)
This commit is contained in:
claude
2026-08-14 07:48:52 +00:00
parent 051b02d3cd
commit 8d75652949
66 changed files with 12834 additions and 5458 deletions

View File

@@ -1,43 +1,43 @@
import math
from typing import List, Optional
from vllm.core.block.common import BlockList
import math
from typing import List, Optional
from vllm.core.block.common import BlockList
from vllm.core.block.interfaces import Block, DeviceAwareBlockAllocator
from vllm.utils import Device, cdiv, chunk_list
class BlockTable:
"""A class to manage blocks for a specific sequence.
The BlockTable maps a sequence of tokens to a list of blocks, where each
block represents a contiguous memory allocation for a portion of the
sequence. The blocks are managed by a DeviceAwareBlockAllocator, which is
responsible for allocating and freeing memory for the blocks.
Args:
block_size (int): The maximum number of tokens that can be stored in a
single block.
block_allocator (DeviceAwareBlockAllocator): The block allocator used to
manage memory for the blocks.
_blocks (Optional[List[Block]], optional): An optional list of existing
blocks to initialize the BlockTable with. If not provided, an empty
BlockTable is created.
max_block_sliding_window (Optional[int], optional): The number of
blocks to keep around for each sequance. If None, all blocks
are kept (eg., when sliding window is not used).
It should at least fit the sliding window size of the model.
Attributes:
_block_size (int): The maximum number of tokens that can be stored in a
single block.
_allocator (DeviceAwareBlockAllocator): The block allocator used to
manage memory for the blocks.
_blocks (Optional[List[Block]]): The list of blocks managed by this
BlockTable.
_num_full_slots (int): The number of tokens currently stored in the
blocks.
"""
from vllm.utils import Device, cdiv, chunk_list
class BlockTable:
"""A class to manage blocks for a specific sequence.
The BlockTable maps a sequence of tokens to a list of blocks, where each
block represents a contiguous memory allocation for a portion of the
sequence. The blocks are managed by a DeviceAwareBlockAllocator, which is
responsible for allocating and freeing memory for the blocks.
Args:
block_size (int): The maximum number of tokens that can be stored in a
single block.
block_allocator (DeviceAwareBlockAllocator): The block allocator used to
manage memory for the blocks.
_blocks (Optional[List[Block]], optional): An optional list of existing
blocks to initialize the BlockTable with. If not provided, an empty
BlockTable is created.
max_block_sliding_window (Optional[int], optional): The number of
blocks to keep around for each sequance. If None, all blocks
are kept (eg., when sliding window is not used).
It should at least fit the sliding window size of the model.
Attributes:
_block_size (int): The maximum number of tokens that can be stored in a
single block.
_allocator (DeviceAwareBlockAllocator): The block allocator used to
manage memory for the blocks.
_blocks (Optional[List[Block]]): The list of blocks managed by this
BlockTable.
_num_full_slots (int): The number of tokens currently stored in the
blocks.
"""
def __init__(
self,
block_size: int,
@@ -52,55 +52,55 @@ class BlockTable:
if _blocks is None:
_blocks = []
self._blocks: BlockList = BlockList(_blocks)
self._max_block_sliding_window = max_block_sliding_window
self._num_full_slots = self._get_num_token_ids()
@staticmethod
def get_num_required_blocks(token_ids: List[int],
block_size: int,
num_lookahead_slots: int = 0) -> int:
"""Calculates the minimum number of blocks required to store a given
sequence of token IDs along with any look-ahead slots that may be
required (like in multi-step + chunked-prefill).
This assumes worst-case scenario, where every block requires a new
allocation (e.g. ignoring prefix caching).
Args:
token_ids (List[int]): The sequence of token IDs to be stored.
block_size (int): The maximum number of tokens that can be stored in
a single block.
num_lookahead_slots (int): look-ahead slots that the sequence may
require.
Returns:
int: The minimum number of blocks required to store the given
sequence of token IDs along with any required look-ahead slots.
"""
return cdiv(len(token_ids) + num_lookahead_slots, block_size)
self._max_block_sliding_window = max_block_sliding_window
self._num_full_slots = self._get_num_token_ids()
@staticmethod
def get_num_required_blocks(token_ids: List[int],
block_size: int,
num_lookahead_slots: int = 0) -> int:
"""Calculates the minimum number of blocks required to store a given
sequence of token IDs along with any look-ahead slots that may be
required (like in multi-step + chunked-prefill).
This assumes worst-case scenario, where every block requires a new
allocation (e.g. ignoring prefix caching).
Args:
token_ids (List[int]): The sequence of token IDs to be stored.
block_size (int): The maximum number of tokens that can be stored in
a single block.
num_lookahead_slots (int): look-ahead slots that the sequence may
require.
Returns:
int: The minimum number of blocks required to store the given
sequence of token IDs along with any required look-ahead slots.
"""
return cdiv(len(token_ids) + num_lookahead_slots, block_size)
def allocate(self,
token_ids: List[int],
device: Device = Device.GPU) -> None:
"""Allocates memory blocks for storing the given sequence of token IDs.
This method allocates the required number of blocks to store the given
sequence of token IDs.
Args:
token_ids (List[int]): The sequence of token IDs to be stored.
device (Device, optional): The device on which the blocks should be
allocated. Defaults to Device.GPU.
"""
"""Allocates memory blocks for storing the given sequence of token IDs.
This method allocates the required number of blocks to store the given
sequence of token IDs.
Args:
token_ids (List[int]): The sequence of token IDs to be stored.
device (Device, optional): The device on which the blocks should be
allocated. Defaults to Device.GPU.
"""
assert not self._is_allocated
assert token_ids
blocks = self._allocate_blocks_for_token_ids(prev_block=None,
token_ids=token_ids,
device=device)
self.update(blocks)
self._num_full_slots = len(token_ids)
self.update(blocks)
self._num_full_slots = len(token_ids)
def update(self, blocks: List[Block]) -> None:
"""Resets the table to the newly provided blocks
(with their corresponding block ids)
@@ -115,106 +115,106 @@ class BlockTable:
if block_hash is not None:
content_hashes.append(block_hash)
return content_hashes
def append_token_ids(self,
token_ids: List[int],
num_lookahead_slots: int = 0,
num_computed_slots: Optional[int] = None) -> None:
"""Appends a sequence of token IDs to the existing blocks in the
BlockTable.
This method appends the given sequence of token IDs to the existing
blocks in the BlockTable. If there is not enough space in the existing
blocks, new blocks are allocated using the `ensure_num_empty_slots`
method to accommodate the additional tokens.
The token IDs are divided into chunks of size `block_size` (except for
the first chunk, which may be smaller), and each chunk is appended to a
separate block.
Args:
token_ids (List[int]): The sequence of token IDs to be appended.
num_computed_slots (Optional[int]): The number of KV cache slots
that are already filled (computed).
When sliding window is enabled, this is used to compute how many
blocks to drop at the front of the sequence.
Without sliding window, None can be passed.
Without chunked prefill, it should be the same as
_num_full_slots.
"""
assert self._is_allocated, "no blocks have been allocated"
assert len(self._blocks) > 0
# Drop blocks that are no longer needed due to sliding window
if self._max_block_sliding_window is not None:
null_block = self._allocator.allocate_or_get_null_block()
assert num_computed_slots is not None
end_block_idx = (num_computed_slots //
self._block_size) - self._max_block_sliding_window
for idx in range(0, end_block_idx):
b = self._blocks[idx]
if b is not null_block:
self._allocator.free(b)
self._blocks[idx] = null_block
# Ensure there are enough empty slots for the new tokens plus
# lookahead slots
self.ensure_num_empty_slots(num_empty_slots=len(token_ids) +
num_lookahead_slots)
# Update the blocks with the new tokens
first_block_idx = self._num_full_slots // self._block_size
token_blocks = self._chunk_token_blocks_for_append(token_ids)
for i, token_block in enumerate(token_blocks):
self._blocks.append_token_ids(first_block_idx + i, token_block)
self._num_full_slots += len(token_ids)
def ensure_num_empty_slots(self, num_empty_slots: int) -> None:
"""Ensures that the BlockTable has at least the specified number of
empty slots available.
This method checks if the BlockTable has enough empty slots (i.e.,
available space) to accommodate the requested number of tokens. If not,
it allocates additional blocks on the GPU to ensure that the required
number of empty slots is available.
Args:
num_empty_slots (int): The minimum number of empty slots required.
"""
# Currently the block table only supports
# appending tokens to GPU blocks.
device = Device.GPU
assert self._is_allocated
if self._num_empty_slots >= num_empty_slots:
return
slots_to_allocate = num_empty_slots - self._num_empty_slots
blocks_to_allocate = cdiv(slots_to_allocate, self._block_size)
for _ in range(blocks_to_allocate):
assert len(self._blocks) > 0
self._blocks.append(
self._allocator.allocate_mutable_block(
prev_block=self._blocks[-1], device=device))
def fork(self) -> "BlockTable":
"""Creates a new BlockTable instance with a copy of the blocks from the
current instance.
This method creates a new BlockTable instance with the same block size,
block allocator, and a copy of the blocks from the current instance. The
new BlockTable has its own independent set of blocks, but shares the
same underlying memory allocation with the original BlockTable.
Returns:
BlockTable: A new BlockTable instance with a copy of the blocks from
the current instance.
"""
assert self._is_allocated
assert len(self._blocks) > 0
def append_token_ids(self,
token_ids: List[int],
num_lookahead_slots: int = 0,
num_computed_slots: Optional[int] = None) -> None:
"""Appends a sequence of token IDs to the existing blocks in the
BlockTable.
This method appends the given sequence of token IDs to the existing
blocks in the BlockTable. If there is not enough space in the existing
blocks, new blocks are allocated using the `ensure_num_empty_slots`
method to accommodate the additional tokens.
The token IDs are divided into chunks of size `block_size` (except for
the first chunk, which may be smaller), and each chunk is appended to a
separate block.
Args:
token_ids (List[int]): The sequence of token IDs to be appended.
num_computed_slots (Optional[int]): The number of KV cache slots
that are already filled (computed).
When sliding window is enabled, this is used to compute how many
blocks to drop at the front of the sequence.
Without sliding window, None can be passed.
Without chunked prefill, it should be the same as
_num_full_slots.
"""
assert self._is_allocated, "no blocks have been allocated"
assert len(self._blocks) > 0
# Drop blocks that are no longer needed due to sliding window
if self._max_block_sliding_window is not None:
null_block = self._allocator.allocate_or_get_null_block()
assert num_computed_slots is not None
end_block_idx = (num_computed_slots //
self._block_size) - self._max_block_sliding_window
for idx in range(0, end_block_idx):
b = self._blocks[idx]
if b is not null_block:
self._allocator.free(b)
self._blocks[idx] = null_block
# Ensure there are enough empty slots for the new tokens plus
# lookahead slots
self.ensure_num_empty_slots(num_empty_slots=len(token_ids) +
num_lookahead_slots)
# Update the blocks with the new tokens
first_block_idx = self._num_full_slots // self._block_size
token_blocks = self._chunk_token_blocks_for_append(token_ids)
for i, token_block in enumerate(token_blocks):
self._blocks.append_token_ids(first_block_idx + i, token_block)
self._num_full_slots += len(token_ids)
def ensure_num_empty_slots(self, num_empty_slots: int) -> None:
"""Ensures that the BlockTable has at least the specified number of
empty slots available.
This method checks if the BlockTable has enough empty slots (i.e.,
available space) to accommodate the requested number of tokens. If not,
it allocates additional blocks on the GPU to ensure that the required
number of empty slots is available.
Args:
num_empty_slots (int): The minimum number of empty slots required.
"""
# Currently the block table only supports
# appending tokens to GPU blocks.
device = Device.GPU
assert self._is_allocated
if self._num_empty_slots >= num_empty_slots:
return
slots_to_allocate = num_empty_slots - self._num_empty_slots
blocks_to_allocate = cdiv(slots_to_allocate, self._block_size)
for _ in range(blocks_to_allocate):
assert len(self._blocks) > 0
self._blocks.append(
self._allocator.allocate_mutable_block(
prev_block=self._blocks[-1], device=device))
def fork(self) -> "BlockTable":
"""Creates a new BlockTable instance with a copy of the blocks from the
current instance.
This method creates a new BlockTable instance with the same block size,
block allocator, and a copy of the blocks from the current instance. The
new BlockTable has its own independent set of blocks, but shares the
same underlying memory allocation with the original BlockTable.
Returns:
BlockTable: A new BlockTable instance with a copy of the blocks from
the current instance.
"""
assert self._is_allocated
assert len(self._blocks) > 0
forked_blocks = self._allocator.fork(self._blocks[-1])
return BlockTable(
block_size=self._block_size,
@@ -223,84 +223,84 @@ class BlockTable:
max_block_sliding_window=self._max_block_sliding_window,
cache_namespace=self._cache_namespace,
)
def free(self) -> None:
"""Frees the memory occupied by the blocks in the BlockTable.
This method iterates over all the blocks in the `_blocks` list and calls
the `free` method of the `_allocator` object to release the memory
occupied by each block. After freeing all the blocks, the `_blocks` list
is set to `None`.
"""
for block in self.blocks:
self._allocator.free(block)
self._blocks.reset()
@property
def physical_block_ids(self) -> List[int]:
"""Returns a list of physical block indices for the blocks in the
BlockTable.
This property returns a list of integers, where each integer represents
the physical block index of a corresponding block in the `_blocks` list.
The physical block index is a unique identifier for the memory location
occupied by the block.
Returns:
List[int]: A list of physical block indices for the blocks in the
BlockTable.
"""
return self._blocks.ids()
def get_unseen_token_ids(self, sequence_token_ids: List[int]) -> List[int]:
"""Get the number of "unseen" tokens in the sequence.
Unseen tokens are tokens in the sequence corresponding to this block
table, but are not yet appended to this block table.
Args:
sequence_token_ids (List[int]): The list of token ids in the
sequence.
Returns:
List[int]: The postfix of sequence_token_ids that has not yet been
appended to the block table.
"""
# Since the block table is append-only, the unseen token ids are the
# ones after the appended ones.
return sequence_token_ids[self.num_full_slots:]
def free(self) -> None:
"""Frees the memory occupied by the blocks in the BlockTable.
This method iterates over all the blocks in the `_blocks` list and calls
the `free` method of the `_allocator` object to release the memory
occupied by each block. After freeing all the blocks, the `_blocks` list
is set to `None`.
"""
for block in self.blocks:
self._allocator.free(block)
self._blocks.reset()
@property
def physical_block_ids(self) -> List[int]:
"""Returns a list of physical block indices for the blocks in the
BlockTable.
This property returns a list of integers, where each integer represents
the physical block index of a corresponding block in the `_blocks` list.
The physical block index is a unique identifier for the memory location
occupied by the block.
Returns:
List[int]: A list of physical block indices for the blocks in the
BlockTable.
"""
return self._blocks.ids()
def get_unseen_token_ids(self, sequence_token_ids: List[int]) -> List[int]:
"""Get the number of "unseen" tokens in the sequence.
Unseen tokens are tokens in the sequence corresponding to this block
table, but are not yet appended to this block table.
Args:
sequence_token_ids (List[int]): The list of token ids in the
sequence.
Returns:
List[int]: The postfix of sequence_token_ids that has not yet been
appended to the block table.
"""
# Since the block table is append-only, the unseen token ids are the
# ones after the appended ones.
return sequence_token_ids[self.num_full_slots:]
def _allocate_blocks_for_token_ids(self, prev_block: Optional[Block],
token_ids: List[int],
device: Device) -> List[Block]:
blocks: List[Block] = []
block_token_ids = []
tail_token_ids = []
for cur_token_ids in chunk_list(token_ids, self._block_size):
if len(cur_token_ids) == self._block_size:
block_token_ids.append(cur_token_ids)
else:
tail_token_ids.append(cur_token_ids)
tail_token_ids = []
for cur_token_ids in chunk_list(token_ids, self._block_size):
if len(cur_token_ids) == self._block_size:
block_token_ids.append(cur_token_ids)
else:
tail_token_ids.append(cur_token_ids)
if block_token_ids:
blocks.extend(self._allocate_immutable_blocks(
prev_block=prev_block,
block_token_ids=block_token_ids,
device=device))
prev_block = blocks[-1]
if tail_token_ids:
assert len(tail_token_ids) == 1
cur_token_ids = tail_token_ids[0]
if tail_token_ids:
assert len(tail_token_ids) == 1
cur_token_ids = tail_token_ids[0]
block = self._allocate_mutable_block(prev_block=prev_block,
device=device)
block.append_token_ids(cur_token_ids)
blocks.append(block)
block.append_token_ids(cur_token_ids)
blocks.append(block)
return blocks
def _allocate_mutable_block(self, prev_block: Optional[Block],
@@ -372,85 +372,85 @@ class BlockTable:
prev_block,
block_token_ids=block_token_ids,
device=device)
def _get_all_token_ids(self) -> List[int]:
# NOTE: This function is O(seq_len); use sparingly.
token_ids: List[int] = []
if not self._is_allocated:
return token_ids
for block in self.blocks:
token_ids.extend(block.token_ids)
return token_ids
def _get_num_token_ids(self) -> int:
res = 0
for block in self.blocks:
res += len(block.token_ids)
return res
@property
def _is_allocated(self) -> bool:
return len(self._blocks) > 0
@property
def blocks(self) -> List[Block]:
return self._blocks.list()
@property
def _num_empty_slots(self) -> int:
assert self._is_allocated
return len(self._blocks) * self._block_size - self._num_full_slots
@property
def num_full_slots(self) -> int:
"""Returns the total number of tokens currently stored in the
BlockTable.
Returns:
int: The total number of tokens currently stored in the BlockTable.
"""
return self._num_full_slots
def get_num_blocks_touched_by_append_slots(
self, token_ids: List[int], num_lookahead_slots: int) -> int:
"""Determine how many blocks will be "touched" by appending the token
ids.
This is required for the scheduler to determine whether a sequence can
continue generation, or if it must be preempted.
"""
# Math below is equivalent to:
# all_token_ids = token_ids + [-1] * num_lookahead_slots
# token_blocks = self._chunk_token_blocks_for_append(all_token_ids)
# return len(token_blocks)
num_token_ids = len(token_ids) + num_lookahead_slots
first_chunk_size = self._block_size - (self._num_full_slots %
self._block_size)
num_token_blocks = (1 + math.ceil(
(num_token_ids - first_chunk_size) / self._block_size))
return num_token_blocks
def _chunk_token_blocks_for_append(
self, token_ids: List[int]) -> List[List[int]]:
"""Split the token ids into block-sized chunks so they can be easily
appended to blocks. The first such "token block" may have less token ids
than the block size, since the last allocated block may be partially
full.
If no token ids are provided, then no chunks are returned.
"""
if not token_ids:
return []
first_chunk_size = self._block_size - (self._num_full_slots %
self._block_size)
token_blocks = [token_ids[:first_chunk_size]]
token_blocks.extend(
chunk_list(token_ids[first_chunk_size:], self._block_size))
return token_blocks
def _get_all_token_ids(self) -> List[int]:
# NOTE: This function is O(seq_len); use sparingly.
token_ids: List[int] = []
if not self._is_allocated:
return token_ids
for block in self.blocks:
token_ids.extend(block.token_ids)
return token_ids
def _get_num_token_ids(self) -> int:
res = 0
for block in self.blocks:
res += len(block.token_ids)
return res
@property
def _is_allocated(self) -> bool:
return len(self._blocks) > 0
@property
def blocks(self) -> List[Block]:
return self._blocks.list()
@property
def _num_empty_slots(self) -> int:
assert self._is_allocated
return len(self._blocks) * self._block_size - self._num_full_slots
@property
def num_full_slots(self) -> int:
"""Returns the total number of tokens currently stored in the
BlockTable.
Returns:
int: The total number of tokens currently stored in the BlockTable.
"""
return self._num_full_slots
def get_num_blocks_touched_by_append_slots(
self, token_ids: List[int], num_lookahead_slots: int) -> int:
"""Determine how many blocks will be "touched" by appending the token
ids.
This is required for the scheduler to determine whether a sequence can
continue generation, or if it must be preempted.
"""
# Math below is equivalent to:
# all_token_ids = token_ids + [-1] * num_lookahead_slots
# token_blocks = self._chunk_token_blocks_for_append(all_token_ids)
# return len(token_blocks)
num_token_ids = len(token_ids) + num_lookahead_slots
first_chunk_size = self._block_size - (self._num_full_slots %
self._block_size)
num_token_blocks = (1 + math.ceil(
(num_token_ids - first_chunk_size) / self._block_size))
return num_token_blocks
def _chunk_token_blocks_for_append(
self, token_ids: List[int]) -> List[List[int]]:
"""Split the token ids into block-sized chunks so they can be easily
appended to blocks. The first such "token block" may have less token ids
than the block size, since the last allocated block may be partially
full.
If no token ids are provided, then no chunks are returned.
"""
if not token_ids:
return []
first_chunk_size = self._block_size - (self._num_full_slots %
self._block_size)
token_blocks = [token_ids[:first_chunk_size]]
token_blocks.extend(
chunk_list(token_ids[first_chunk_size:], self._block_size))
return token_blocks

View File

@@ -4,56 +4,56 @@ from vllm.core.block.cpu_kv_content_cache import (CpuKvContentCache,
cpu_kv_offload_enabled)
from vllm.core.block.interfaces import (Block, BlockAllocator, BlockId,
DeviceAwareBlockAllocator)
from vllm.core.block.naive_block import NaiveBlock, NaiveBlockAllocator
from vllm.core.block.prefix_caching_block import PrefixCachingBlockAllocator
from vllm.utils import Device
class CpuGpuBlockAllocator(DeviceAwareBlockAllocator):
"""A block allocator that can allocate blocks on both CPU and GPU memory.
This class implements the `DeviceAwareBlockAllocator` interface and provides
functionality for allocating and managing blocks of memory on both CPU and
GPU devices.
The `CpuGpuBlockAllocator` maintains separate memory pools for CPU and GPU
blocks, and allows for allocation, deallocation, forking, and swapping of
blocks across these memory pools.
"""
@staticmethod
def create(
allocator_type: str,
num_gpu_blocks: int,
num_cpu_blocks: int,
block_size: int,
) -> DeviceAwareBlockAllocator:
"""Creates a CpuGpuBlockAllocator instance with the specified
configuration.
This static method creates and returns a CpuGpuBlockAllocator instance
based on the provided parameters. It initializes the CPU and GPU block
allocators with the specified number of blocks, block size, and
allocator type.
Args:
allocator_type (str): The type of block allocator to use for CPU
and GPU blocks. Currently supported values are "naive" and
"prefix_caching".
num_gpu_blocks (int): The number of blocks to allocate for GPU
memory.
num_cpu_blocks (int): The number of blocks to allocate for CPU
memory.
block_size (int): The size of each block in number of tokens.
Returns:
DeviceAwareBlockAllocator: A CpuGpuBlockAllocator instance with the
specified configuration.
Notes:
- The block IDs are assigned contiguously, with GPU block IDs coming
before CPU block IDs.
"""
from vllm.core.block.naive_block import NaiveBlock, NaiveBlockAllocator
from vllm.core.block.prefix_caching_block import PrefixCachingBlockAllocator
from vllm.utils import Device
class CpuGpuBlockAllocator(DeviceAwareBlockAllocator):
"""A block allocator that can allocate blocks on both CPU and GPU memory.
This class implements the `DeviceAwareBlockAllocator` interface and provides
functionality for allocating and managing blocks of memory on both CPU and
GPU devices.
The `CpuGpuBlockAllocator` maintains separate memory pools for CPU and GPU
blocks, and allows for allocation, deallocation, forking, and swapping of
blocks across these memory pools.
"""
@staticmethod
def create(
allocator_type: str,
num_gpu_blocks: int,
num_cpu_blocks: int,
block_size: int,
) -> DeviceAwareBlockAllocator:
"""Creates a CpuGpuBlockAllocator instance with the specified
configuration.
This static method creates and returns a CpuGpuBlockAllocator instance
based on the provided parameters. It initializes the CPU and GPU block
allocators with the specified number of blocks, block size, and
allocator type.
Args:
allocator_type (str): The type of block allocator to use for CPU
and GPU blocks. Currently supported values are "naive" and
"prefix_caching".
num_gpu_blocks (int): The number of blocks to allocate for GPU
memory.
num_cpu_blocks (int): The number of blocks to allocate for CPU
memory.
block_size (int): The size of each block in number of tokens.
Returns:
DeviceAwareBlockAllocator: A CpuGpuBlockAllocator instance with the
specified configuration.
Notes:
- The block IDs are assigned contiguously, with GPU block IDs coming
before CPU block IDs.
"""
content_offload = cpu_kv_offload_enabled()
if content_offload and allocator_type != "prefix_caching":
raise RuntimeError(
@@ -63,38 +63,38 @@ class CpuGpuBlockAllocator(DeviceAwareBlockAllocator):
"BI100_CPU_KV_OFFLOAD=1 requires at least one CPU KV block")
block_ids = list(range(num_gpu_blocks + num_cpu_blocks))
gpu_block_ids = block_ids[:num_gpu_blocks]
cpu_block_ids = block_ids[num_gpu_blocks:]
if allocator_type == "naive":
gpu_allocator: BlockAllocator = NaiveBlockAllocator(
create_block=NaiveBlock, # type: ignore
num_blocks=num_gpu_blocks,
block_size=block_size,
block_ids=gpu_block_ids,
)
cpu_allocator: BlockAllocator = NaiveBlockAllocator(
create_block=NaiveBlock, # type: ignore
num_blocks=num_cpu_blocks,
block_size=block_size,
block_ids=cpu_block_ids,
)
elif allocator_type == "prefix_caching":
gpu_allocator = PrefixCachingBlockAllocator(
num_blocks=num_gpu_blocks,
block_size=block_size,
block_ids=gpu_block_ids,
)
cpu_allocator = PrefixCachingBlockAllocator(
num_blocks=num_cpu_blocks,
block_size=block_size,
block_ids=cpu_block_ids,
)
else:
raise ValueError(f"Unknown allocator type {allocator_type=}")
gpu_block_ids = block_ids[:num_gpu_blocks]
cpu_block_ids = block_ids[num_gpu_blocks:]
if allocator_type == "naive":
gpu_allocator: BlockAllocator = NaiveBlockAllocator(
create_block=NaiveBlock, # type: ignore
num_blocks=num_gpu_blocks,
block_size=block_size,
block_ids=gpu_block_ids,
)
cpu_allocator: BlockAllocator = NaiveBlockAllocator(
create_block=NaiveBlock, # type: ignore
num_blocks=num_cpu_blocks,
block_size=block_size,
block_ids=cpu_block_ids,
)
elif allocator_type == "prefix_caching":
gpu_allocator = PrefixCachingBlockAllocator(
num_blocks=num_gpu_blocks,
block_size=block_size,
block_ids=gpu_block_ids,
)
cpu_allocator = PrefixCachingBlockAllocator(
num_blocks=num_cpu_blocks,
block_size=block_size,
block_ids=cpu_block_ids,
)
else:
raise ValueError(f"Unknown allocator type {allocator_type=}")
return CpuGpuBlockAllocator(
cpu_block_allocator=cpu_allocator,
gpu_block_allocator=gpu_allocator,
@@ -105,21 +105,21 @@ class CpuGpuBlockAllocator(DeviceAwareBlockAllocator):
def __init__(self, cpu_block_allocator: BlockAllocator,
gpu_block_allocator: BlockAllocator,
cpu_content_cache: Optional[CpuKvContentCache] = None):
assert not (
cpu_block_allocator.all_block_ids
& gpu_block_allocator.all_block_ids
), "cpu and gpu block allocators can't have intersection of block ids"
self._allocators = {
Device.CPU: cpu_block_allocator,
Device.GPU: gpu_block_allocator,
}
assert not (
cpu_block_allocator.all_block_ids
& gpu_block_allocator.all_block_ids
), "cpu and gpu block allocators can't have intersection of block ids"
self._allocators = {
Device.CPU: cpu_block_allocator,
Device.GPU: gpu_block_allocator,
}
self._swap_mapping: Dict[int, int] = {}
self._null_block: Optional[Block] = None
self._cpu_content_cache = cpu_content_cache
self._block_ids_to_allocator: Dict[int, BlockAllocator] = {}
self._block_ids_to_allocator: Dict[int, BlockAllocator] = {}
for _, allocator in self._allocators.items():
for block_id in allocator.all_block_ids:
self._block_ids_to_allocator[block_id] = allocator
@@ -164,236 +164,236 @@ class CpuGpuBlockAllocator(DeviceAwareBlockAllocator):
assert self._cpu_content_cache is not None
gpu_slot = self.get_physical_block_id(Device.GPU, gpu_block_id)
return self._cpu_content_cache.stage_store(content_hash, gpu_slot)
def allocate_or_get_null_block(self) -> Block:
if self._null_block is None:
self._null_block = NullBlock(
self.allocate_mutable_block(None, Device.GPU))
return self._null_block
def allocate_mutable_block(self, prev_block: Optional[Block],
device: Device) -> Block:
"""Allocates a new mutable block on the specified device.
Args:
prev_block (Optional[Block]): The previous block to in the sequence.
Used for prefix hashing.
device (Device): The device on which to allocate the new block.
Returns:
Block: The newly allocated mutable block.
"""
return self._allocators[device].allocate_mutable_block(prev_block)
def allocate_immutable_blocks(self, prev_block: Optional[Block],
block_token_ids: List[List[int]],
device: Device) -> List[Block]:
"""Allocates a new group of immutable blocks with the provided block
token IDs on the specified device.
Args:
prev_block (Optional[Block]): The previous block in the sequence.
Used for prefix hashing.
block_token_ids (List[int]): The list of block token IDs to be
stored in the new blocks.
device (Device): The device on which to allocate the new block.
Returns:
List[Block]: The newly allocated list of immutable blocks
containing the provided block token IDs.
"""
return self._allocators[device].allocate_immutable_blocks(
prev_block, block_token_ids)
def allocate_immutable_block(self, prev_block: Optional[Block],
token_ids: List[int],
device: Device) -> Block:
"""Allocates a new immutable block with the provided token IDs on the
specified device.
Args:
prev_block (Optional[Block]): The previous block in the sequence.
Used for prefix hashing.
token_ids (List[int]): The list of token IDs to be stored in the new
block.
device (Device): The device on which to allocate the new block.
Returns:
Block: The newly allocated immutable block containing the provided
token IDs.
"""
return self._allocators[device].allocate_immutable_block(
prev_block, token_ids)
def free(self, block: Block) -> None:
"""Frees the memory occupied by the given block.
Args:
block (Block): The block to be freed.
"""
# Null block should never be freed
if isinstance(block, NullBlock):
return
block_id = block.block_id
assert block_id is not None
allocator = self._block_ids_to_allocator[block_id]
allocator.free(block)
def fork(self, last_block: Block) -> List[Block]:
"""Creates a new sequence of blocks that shares the same underlying
memory as the original sequence.
Args:
last_block (Block): The last block in the original sequence.
Returns:
List[Block]: A new list of blocks that shares the same memory as the
original sequence.
"""
# do not attempt to fork the null block
assert not isinstance(last_block, NullBlock)
block_id = last_block.block_id
assert block_id is not None
allocator = self._block_ids_to_allocator[block_id]
return allocator.fork(last_block)
def get_num_free_blocks(self, device: Device) -> int:
"""Returns the number of free blocks available on the specified device.
Args:
device (Device): The device for which to query the number of free
blocks. AssertionError is raised if None is passed.
Returns:
int: The number of free blocks available on the specified device.
"""
return self._allocators[device].get_num_free_blocks()
def get_num_total_blocks(self, device: Device) -> int:
return self._allocators[device].get_num_total_blocks()
def get_physical_block_id(self, device: Device, absolute_id: int) -> int:
"""Returns the zero-offset block id on certain device given the
absolute block id.
Args:
device (Device): The device for which to query relative block id.
absolute_id (int): The absolute block id for the block in
whole allocator.
Returns:
int: The zero-offset block id on certain device.
"""
return self._allocators[device].get_physical_block_id(absolute_id)
def allocate_or_get_null_block(self) -> Block:
if self._null_block is None:
self._null_block = NullBlock(
self.allocate_mutable_block(None, Device.GPU))
return self._null_block
def allocate_mutable_block(self, prev_block: Optional[Block],
device: Device) -> Block:
"""Allocates a new mutable block on the specified device.
Args:
prev_block (Optional[Block]): The previous block to in the sequence.
Used for prefix hashing.
device (Device): The device on which to allocate the new block.
Returns:
Block: The newly allocated mutable block.
"""
return self._allocators[device].allocate_mutable_block(prev_block)
def allocate_immutable_blocks(self, prev_block: Optional[Block],
block_token_ids: List[List[int]],
device: Device) -> List[Block]:
"""Allocates a new group of immutable blocks with the provided block
token IDs on the specified device.
Args:
prev_block (Optional[Block]): The previous block in the sequence.
Used for prefix hashing.
block_token_ids (List[int]): The list of block token IDs to be
stored in the new blocks.
device (Device): The device on which to allocate the new block.
Returns:
List[Block]: The newly allocated list of immutable blocks
containing the provided block token IDs.
"""
return self._allocators[device].allocate_immutable_blocks(
prev_block, block_token_ids)
def allocate_immutable_block(self, prev_block: Optional[Block],
token_ids: List[int],
device: Device) -> Block:
"""Allocates a new immutable block with the provided token IDs on the
specified device.
Args:
prev_block (Optional[Block]): The previous block in the sequence.
Used for prefix hashing.
token_ids (List[int]): The list of token IDs to be stored in the new
block.
device (Device): The device on which to allocate the new block.
Returns:
Block: The newly allocated immutable block containing the provided
token IDs.
"""
return self._allocators[device].allocate_immutable_block(
prev_block, token_ids)
def free(self, block: Block) -> None:
"""Frees the memory occupied by the given block.
Args:
block (Block): The block to be freed.
"""
# Null block should never be freed
if isinstance(block, NullBlock):
return
block_id = block.block_id
assert block_id is not None
allocator = self._block_ids_to_allocator[block_id]
allocator.free(block)
def fork(self, last_block: Block) -> List[Block]:
"""Creates a new sequence of blocks that shares the same underlying
memory as the original sequence.
Args:
last_block (Block): The last block in the original sequence.
Returns:
List[Block]: A new list of blocks that shares the same memory as the
original sequence.
"""
# do not attempt to fork the null block
assert not isinstance(last_block, NullBlock)
block_id = last_block.block_id
assert block_id is not None
allocator = self._block_ids_to_allocator[block_id]
return allocator.fork(last_block)
def get_num_free_blocks(self, device: Device) -> int:
"""Returns the number of free blocks available on the specified device.
Args:
device (Device): The device for which to query the number of free
blocks. AssertionError is raised if None is passed.
Returns:
int: The number of free blocks available on the specified device.
"""
return self._allocators[device].get_num_free_blocks()
def get_num_total_blocks(self, device: Device) -> int:
return self._allocators[device].get_num_total_blocks()
def get_physical_block_id(self, device: Device, absolute_id: int) -> int:
"""Returns the zero-offset block id on certain device given the
absolute block id.
Args:
device (Device): The device for which to query relative block id.
absolute_id (int): The absolute block id for the block in
whole allocator.
Returns:
int: The zero-offset block id on certain device.
"""
return self._allocators[device].get_physical_block_id(absolute_id)
def swap(self, blocks: List[Block], src_device: Device,
dst_device: Device) -> Dict[int, int]:
"""Execute the swap for the given blocks from source_device
on to dest_device, save the current swap mapping and append
them to the accumulated `self._swap_mapping` for each
scheduling move.
Args:
blocks: List of blocks to be swapped.
src_device (Device): Device to swap the 'blocks' from.
dst_device (Device): Device to swap the 'blocks' to.
Returns:
Dict[int, int]: Swap mapping from source_device
on to dest_device.
"""
"""Execute the swap for the given blocks from source_device
on to dest_device, save the current swap mapping and append
them to the accumulated `self._swap_mapping` for each
scheduling move.
Args:
blocks: List of blocks to be swapped.
src_device (Device): Device to swap the 'blocks' from.
dst_device (Device): Device to swap the 'blocks' to.
Returns:
Dict[int, int]: Swap mapping from source_device
on to dest_device.
"""
if self.content_offload_enabled:
raise RuntimeError(
"request-level preemption swap cannot share CPU slots with "
"BI100_CPU_KV_OFFLOAD")
src_block_ids = [block.block_id for block in blocks]
self._allocators[src_device].swap_out(blocks)
self._allocators[dst_device].swap_in(blocks)
dst_block_ids = [block.block_id for block in blocks]
current_swap_mapping: Dict[int, int] = {}
for src_block_id, dst_block_id in zip(src_block_ids, dst_block_ids):
if src_block_id is not None and dst_block_id is not None:
self._swap_mapping[src_block_id] = dst_block_id
current_swap_mapping[src_block_id] = dst_block_id
return current_swap_mapping
def get_num_full_blocks_touched(self, blocks: List[Block],
device: Device) -> int:
"""Returns the number of full blocks that will be touched by
swapping in/out the given blocks on to the 'device'.
Args:
blocks: List of blocks to be swapped.
device (Device): Device to swap the 'blocks' on.
Returns:
int: the number of full blocks that will be touched by
swapping in/out the given blocks on to the 'device'.
Non full blocks are ignored when deciding the number
of blocks to touch.
"""
return self._allocators[device].get_num_full_blocks_touched(blocks)
def clear_copy_on_writes(self) -> List[Tuple[int, int]]:
"""Clears the copy-on-write (CoW) state and returns the mapping of
source to destination block IDs.
Returns:
List[Tuple[int, int]]: A list mapping source block IDs to
destination block IDs.
"""
# CoW only supported on GPU
device = Device.GPU
return self._allocators[device].clear_copy_on_writes()
def mark_blocks_as_accessed(self, block_ids: List[int],
now: float) -> None:
"""Mark blocks as accessed, only use for prefix caching."""
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].mark_blocks_as_accessed(block_ids, now)
def mark_blocks_as_computed(self, block_ids: List[int]) -> None:
"""Mark blocks as accessed, only use for prefix caching."""
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].mark_blocks_as_computed(block_ids)
def get_computed_block_ids(self, prev_computed_block_ids: List[int],
block_ids: List[int],
skip_last_block_id: bool) -> List[int]:
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].get_computed_block_ids(
prev_computed_block_ids, block_ids, skip_last_block_id)
def get_common_computed_block_ids(
self, computed_seq_block_ids: List[List[int]]) -> List[int]:
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].get_common_computed_block_ids(
computed_seq_block_ids)
@property
def all_block_ids(self) -> FrozenSet[int]:
return frozenset(self._block_ids_to_allocator.keys())
def get_prefix_cache_hit_rate(self, device: Device) -> float:
"""Prefix cache hit rate. -1 means not supported or disabled."""
assert device in self._allocators
return self._allocators[device].get_prefix_cache_hit_rate()
self._allocators[src_device].swap_out(blocks)
self._allocators[dst_device].swap_in(blocks)
dst_block_ids = [block.block_id for block in blocks]
current_swap_mapping: Dict[int, int] = {}
for src_block_id, dst_block_id in zip(src_block_ids, dst_block_ids):
if src_block_id is not None and dst_block_id is not None:
self._swap_mapping[src_block_id] = dst_block_id
current_swap_mapping[src_block_id] = dst_block_id
return current_swap_mapping
def get_num_full_blocks_touched(self, blocks: List[Block],
device: Device) -> int:
"""Returns the number of full blocks that will be touched by
swapping in/out the given blocks on to the 'device'.
Args:
blocks: List of blocks to be swapped.
device (Device): Device to swap the 'blocks' on.
Returns:
int: the number of full blocks that will be touched by
swapping in/out the given blocks on to the 'device'.
Non full blocks are ignored when deciding the number
of blocks to touch.
"""
return self._allocators[device].get_num_full_blocks_touched(blocks)
def clear_copy_on_writes(self) -> List[Tuple[int, int]]:
"""Clears the copy-on-write (CoW) state and returns the mapping of
source to destination block IDs.
Returns:
List[Tuple[int, int]]: A list mapping source block IDs to
destination block IDs.
"""
# CoW only supported on GPU
device = Device.GPU
return self._allocators[device].clear_copy_on_writes()
def mark_blocks_as_accessed(self, block_ids: List[int],
now: float) -> None:
"""Mark blocks as accessed, only use for prefix caching."""
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].mark_blocks_as_accessed(block_ids, now)
def mark_blocks_as_computed(self, block_ids: List[int]) -> None:
"""Mark blocks as accessed, only use for prefix caching."""
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].mark_blocks_as_computed(block_ids)
def get_computed_block_ids(self, prev_computed_block_ids: List[int],
block_ids: List[int],
skip_last_block_id: bool) -> List[int]:
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].get_computed_block_ids(
prev_computed_block_ids, block_ids, skip_last_block_id)
def get_common_computed_block_ids(
self, computed_seq_block_ids: List[List[int]]) -> List[int]:
# Prefix caching only supported on GPU.
device = Device.GPU
return self._allocators[device].get_common_computed_block_ids(
computed_seq_block_ids)
@property
def all_block_ids(self) -> FrozenSet[int]:
return frozenset(self._block_ids_to_allocator.keys())
def get_prefix_cache_hit_rate(self, device: Device) -> float:
"""Prefix cache hit rate. -1 means not supported or disabled."""
assert device in self._allocators
return self._allocators[device].get_prefix_cache_hit_rate()
def get_and_reset_swaps(self) -> List[Tuple[int, int]]:
"""Returns and clears the mapping of source to destination block IDs.
Will be called after every swapping operations for now, and after every
schedule when BlockManagerV2 become default. Currently not useful.
Returns:
List[Tuple[int, int]]: A mapping of source to destination block IDs.
"""
mapping = self._swap_mapping.copy()
"""Returns and clears the mapping of source to destination block IDs.
Will be called after every swapping operations for now, and after every
schedule when BlockManagerV2 become default. Currently not useful.
Returns:
List[Tuple[int, int]]: A mapping of source to destination block IDs.
"""
mapping = self._swap_mapping.copy()
self._swap_mapping.clear()
return list(mapping.items())
@@ -407,69 +407,69 @@ class CpuGpuBlockAllocator(DeviceAwareBlockAllocator):
def begin_prefix_cache_step(self) -> None:
if self._cpu_content_cache is not None:
self._cpu_content_cache.begin_step()
class NullBlock(Block):
"""
Null blocks are used as a placeholders for KV cache blocks that have
been dropped due to sliding window.
This implementation just wraps an ordinary block and prevents it from
being modified. It also allows for testing if a block is NullBlock
via isinstance().
"""
def __init__(self, proxy: Block):
super().__init__()
self._proxy = proxy
def append_token_ids(self, token_ids: List[BlockId]):
raise ValueError("null block should not be modified")
@property
def block_id(self):
return self._proxy.block_id
@block_id.setter
def block_id(self, value: Optional[BlockId]):
raise ValueError("null block should not be modified")
@property
def token_ids(self) -> List[BlockId]:
return self._proxy.token_ids
@property
def num_tokens_total(self) -> int:
raise NotImplementedError(
"num_tokens_total is not used for null block")
@property
def num_empty_slots(self) -> BlockId:
return self._proxy.num_empty_slots
@property
def is_full(self):
return self._proxy.is_full
@property
def prev_block(self):
return self._proxy.prev_block
@property
def computed(self):
return self._proxy.computed
@computed.setter
def computed(self, value):
self._proxy.computed = value
@property
def last_accessed(self) -> float:
return self._proxy.last_accessed
@last_accessed.setter
def last_accessed(self, last_accessed_ts: float):
self._proxy.last_accessed = last_accessed_ts
@property
def content_hash(self):
return self._proxy.content_hash
class NullBlock(Block):
"""
Null blocks are used as a placeholders for KV cache blocks that have
been dropped due to sliding window.
This implementation just wraps an ordinary block and prevents it from
being modified. It also allows for testing if a block is NullBlock
via isinstance().
"""
def __init__(self, proxy: Block):
super().__init__()
self._proxy = proxy
def append_token_ids(self, token_ids: List[BlockId]):
raise ValueError("null block should not be modified")
@property
def block_id(self):
return self._proxy.block_id
@block_id.setter
def block_id(self, value: Optional[BlockId]):
raise ValueError("null block should not be modified")
@property
def token_ids(self) -> List[BlockId]:
return self._proxy.token_ids
@property
def num_tokens_total(self) -> int:
raise NotImplementedError(
"num_tokens_total is not used for null block")
@property
def num_empty_slots(self) -> BlockId:
return self._proxy.num_empty_slots
@property
def is_full(self):
return self._proxy.is_full
@property
def prev_block(self):
return self._proxy.prev_block
@property
def computed(self):
return self._proxy.computed
@computed.setter
def computed(self, value):
self._proxy.computed = value
@property
def last_accessed(self) -> float:
return self._proxy.last_accessed
@last_accessed.setter
def last_accessed(self, last_accessed_ts: float):
self._proxy.last_accessed = last_accessed_ts
@property
def content_hash(self):
return self._proxy.content_hash

File diff suppressed because it is too large Load Diff

View File

@@ -32,86 +32,86 @@ logger = init_logger(__name__)
class BlockSpaceManagerV2(BlockSpaceManager):
"""BlockSpaceManager which manages the allocation of KV cache.
It owns responsibility for allocation, swapping, allocating memory for
autoregressively-generated tokens, and other advanced features such as
prefix caching, forking/copy-on-write, and sliding-window memory allocation.
This class implements the design described in
https://github.com/vllm-project/vllm/pull/3492.
Lookahead slots
The block manager has the notion of a "lookahead slot". These are slots
in the KV cache that are allocated for a sequence. Unlike the other
allocated slots, the content of these slots is undefined -- the worker
may use the memory allocations in any way.
In practice, a worker could use these lookahead slots to run multiple
forward passes for a single scheduler invocation. Each successive
forward pass would write KV activations to the corresponding lookahead
slot. This allows low inter-token latency use-cases, where the overhead
of continuous batching scheduling is amortized over >1 generated tokens.
Speculative decoding uses lookahead slots to store KV activations of
proposal tokens.
See https://github.com/vllm-project/vllm/pull/3250 for more information
on lookahead scheduling.
Args:
block_size (int): The size of each memory block.
num_gpu_blocks (int): The number of memory blocks allocated on GPU.
num_cpu_blocks (int): The number of memory blocks allocated on CPU.
watermark (float, optional): The threshold used for memory swapping.
Defaults to 0.01.
sliding_window (Optional[int], optional): The size of the sliding
window. Defaults to None.
enable_caching (bool, optional): Flag indicating whether caching is
enabled. Defaults to False.
"""
"""BlockSpaceManager which manages the allocation of KV cache.
It owns responsibility for allocation, swapping, allocating memory for
autoregressively-generated tokens, and other advanced features such as
prefix caching, forking/copy-on-write, and sliding-window memory allocation.
This class implements the design described in
https://github.com/vllm-project/vllm/pull/3492.
Lookahead slots
The block manager has the notion of a "lookahead slot". These are slots
in the KV cache that are allocated for a sequence. Unlike the other
allocated slots, the content of these slots is undefined -- the worker
may use the memory allocations in any way.
In practice, a worker could use these lookahead slots to run multiple
forward passes for a single scheduler invocation. Each successive
forward pass would write KV activations to the corresponding lookahead
slot. This allows low inter-token latency use-cases, where the overhead
of continuous batching scheduling is amortized over >1 generated tokens.
Speculative decoding uses lookahead slots to store KV activations of
proposal tokens.
See https://github.com/vllm-project/vllm/pull/3250 for more information
on lookahead scheduling.
Args:
block_size (int): The size of each memory block.
num_gpu_blocks (int): The number of memory blocks allocated on GPU.
num_cpu_blocks (int): The number of memory blocks allocated on CPU.
watermark (float, optional): The threshold used for memory swapping.
Defaults to 0.01.
sliding_window (Optional[int], optional): The size of the sliding
window. Defaults to None.
enable_caching (bool, optional): Flag indicating whether caching is
enabled. Defaults to False.
"""
def __init__(
self,
block_size: int,
num_gpu_blocks: int,
num_cpu_blocks: int,
watermark: float = 0.01,
sliding_window: Optional[int] = None,
enable_caching: bool = False,
) -> None:
self.block_size = block_size
self.num_total_gpu_blocks = num_gpu_blocks
self.num_total_cpu_blocks = num_cpu_blocks
self.sliding_window = sliding_window
# max_block_sliding_window is the max number of blocks that need to be
# allocated
self.max_block_sliding_window = None
if sliding_window is not None:
# +1 here because // rounds down
num_blocks = sliding_window // block_size + 1
# +1 here because the last block may not be full,
# and so the sequence stretches one more block at the beginning
# For example, if sliding_window is 3 and block_size is 4,
# we may need 2 blocks when the second block only holds 1 token.
self.max_block_sliding_window = num_blocks + 1
self.watermark = watermark
assert watermark >= 0.0
self.enable_caching = enable_caching
self.watermark_blocks = int(watermark * num_gpu_blocks)
self.block_allocator = CpuGpuBlockAllocator.create(
allocator_type="prefix_caching" if enable_caching else "naive",
num_gpu_blocks=num_gpu_blocks,
num_cpu_blocks=num_cpu_blocks,
block_size=block_size,
)
self.block_tables: Dict[SeqId, BlockTable] = {}
watermark: float = 0.01,
sliding_window: Optional[int] = None,
enable_caching: bool = False,
) -> None:
self.block_size = block_size
self.num_total_gpu_blocks = num_gpu_blocks
self.num_total_cpu_blocks = num_cpu_blocks
self.sliding_window = sliding_window
# max_block_sliding_window is the max number of blocks that need to be
# allocated
self.max_block_sliding_window = None
if sliding_window is not None:
# +1 here because // rounds down
num_blocks = sliding_window // block_size + 1
# +1 here because the last block may not be full,
# and so the sequence stretches one more block at the beginning
# For example, if sliding_window is 3 and block_size is 4,
# we may need 2 blocks when the second block only holds 1 token.
self.max_block_sliding_window = num_blocks + 1
self.watermark = watermark
assert watermark >= 0.0
self.enable_caching = enable_caching
self.watermark_blocks = int(watermark * num_gpu_blocks)
self.block_allocator = CpuGpuBlockAllocator.create(
allocator_type="prefix_caching" if enable_caching else "naive",
num_gpu_blocks=num_gpu_blocks,
num_cpu_blocks=num_cpu_blocks,
block_size=block_size,
)
self.block_tables: Dict[SeqId, BlockTable] = {}
self.cross_block_tables: Dict[EncoderSeqId, BlockTable] = {}
self._warned_mm_namespace_requests = set[str]()
self._request_local_namespace: Dict[str, bytes] = {}
@@ -121,46 +121,46 @@ class BlockSpaceManagerV2(BlockSpaceManager):
self.block_allocator)
self._last_access_blocks_tracker = LastAccessBlocksTracker(
self.block_allocator)
def can_allocate(self,
seq_group: SequenceGroup,
num_lookahead_slots: int = 0) -> AllocStatus:
# FIXME(woosuk): Here we assume that all sequences in the group share
# the same prompt. This may not be true for preempted sequences.
check_no_caching_or_swa_for_blockmgr_encdec(self, seq_group)
seq = seq_group.get_seqs(status=SequenceStatus.WAITING)[0]
num_required_blocks = BlockTable.get_num_required_blocks(
seq.get_token_ids(),
block_size=self.block_size,
num_lookahead_slots=num_lookahead_slots,
)
if seq_group.is_encoder_decoder():
encoder_seq = seq_group.get_encoder_seq()
assert encoder_seq is not None
num_required_blocks += BlockTable.get_num_required_blocks(
encoder_seq.get_token_ids(),
block_size=self.block_size,
)
if self.max_block_sliding_window is not None:
num_required_blocks = min(num_required_blocks,
self.max_block_sliding_window)
num_free_gpu_blocks = self.block_allocator.get_num_free_blocks(
device=Device.GPU)
# Use watermark to avoid frequent cache eviction.
if (self.num_total_gpu_blocks - num_required_blocks <
self.watermark_blocks):
return AllocStatus.NEVER
if num_free_gpu_blocks - num_required_blocks >= self.watermark_blocks:
return AllocStatus.OK
else:
return AllocStatus.LATER
def can_allocate(self,
seq_group: SequenceGroup,
num_lookahead_slots: int = 0) -> AllocStatus:
# FIXME(woosuk): Here we assume that all sequences in the group share
# the same prompt. This may not be true for preempted sequences.
check_no_caching_or_swa_for_blockmgr_encdec(self, seq_group)
seq = seq_group.get_seqs(status=SequenceStatus.WAITING)[0]
num_required_blocks = BlockTable.get_num_required_blocks(
seq.get_token_ids(),
block_size=self.block_size,
num_lookahead_slots=num_lookahead_slots,
)
if seq_group.is_encoder_decoder():
encoder_seq = seq_group.get_encoder_seq()
assert encoder_seq is not None
num_required_blocks += BlockTable.get_num_required_blocks(
encoder_seq.get_token_ids(),
block_size=self.block_size,
)
if self.max_block_sliding_window is not None:
num_required_blocks = min(num_required_blocks,
self.max_block_sliding_window)
num_free_gpu_blocks = self.block_allocator.get_num_free_blocks(
device=Device.GPU)
# Use watermark to avoid frequent cache eviction.
if (self.num_total_gpu_blocks - num_required_blocks <
self.watermark_blocks):
return AllocStatus.NEVER
if num_free_gpu_blocks - num_required_blocks >= self.watermark_blocks:
return AllocStatus.OK
else:
return AllocStatus.LATER
def _allocate_sequence(
self,
seq: Sequence,
@@ -181,10 +181,10 @@ class BlockSpaceManagerV2(BlockSpaceManager):
def allocate(self, seq_group: SequenceGroup) -> None:
# Allocate self-attention block tables for decoder sequences
waiting_seqs = seq_group.get_seqs(status=SequenceStatus.WAITING)
assert not (set(seq.seq_id for seq in waiting_seqs)
& self.block_tables.keys()), "block table already exists"
waiting_seqs = seq_group.get_seqs(status=SequenceStatus.WAITING)
assert not (set(seq.seq_id for seq in waiting_seqs)
& self.block_tables.keys()), "block table already exists"
# NOTE: Here we assume that all sequences in the group have the same
# prompt.
seq = waiting_seqs[0]
@@ -199,31 +199,31 @@ class BlockSpaceManagerV2(BlockSpaceManager):
cache_namespace=cache_namespace,
)
self.block_tables[seq.seq_id] = block_table
# Track seq
# Track seq
self._computed_blocks_tracker.add_seq(seq.seq_id)
self._last_access_blocks_tracker.add_seq(seq.seq_id)
# Assign the block table for each sequence.
for seq in waiting_seqs[1:]:
self.block_tables[seq.seq_id] = block_table.fork()
# Track seq
self._computed_blocks_tracker.add_seq(seq.seq_id)
self._last_access_blocks_tracker.add_seq(seq.seq_id)
# Allocate cross-attention block table for encoder sequence
#
# NOTE: Here we assume that all sequences in the group have the same
# encoder prompt.
# Assign the block table for each sequence.
for seq in waiting_seqs[1:]:
self.block_tables[seq.seq_id] = block_table.fork()
# Track seq
self._computed_blocks_tracker.add_seq(seq.seq_id)
self._last_access_blocks_tracker.add_seq(seq.seq_id)
# Allocate cross-attention block table for encoder sequence
#
# NOTE: Here we assume that all sequences in the group have the same
# encoder prompt.
request_id = seq_group.request_id
assert (request_id
not in self.cross_block_tables), \
"block table already exists"
check_no_caching_or_swa_for_blockmgr_encdec(self, seq_group)
check_no_caching_or_swa_for_blockmgr_encdec(self, seq_group)
if seq_group.is_encoder_decoder():
encoder_seq = seq_group.get_encoder_seq()
assert encoder_seq is not None
@@ -279,129 +279,129 @@ class BlockSpaceManagerV2(BlockSpaceManager):
else:
digest.update(b"text|")
return digest.digest()
def can_append_slots(self, seq_group: SequenceGroup,
num_lookahead_slots: int) -> bool:
"""Determine if there is enough space in the GPU KV cache to continue
generation of the specified sequence group.
We use a worst-case heuristic: assume each touched block will require a
new allocation (either via CoW or new block). We can append slots if the
number of touched blocks is less than the number of free blocks.
"Lookahead slots" are slots that are allocated in addition to the slots
for known tokens. The contents of the lookahead slots are not defined.
This is used by speculative decoding when speculating future tokens.
"""
num_touched_blocks = 0
for seq in seq_group.get_seqs(status=SequenceStatus.RUNNING):
block_table = self.block_tables[seq.seq_id]
num_touched_blocks += (
block_table.get_num_blocks_touched_by_append_slots(
token_ids=block_table.get_unseen_token_ids(
seq.get_token_ids()),
num_lookahead_slots=num_lookahead_slots,
))
num_free_gpu_blocks = self.block_allocator.get_num_free_blocks(
Device.GPU)
return num_touched_blocks <= num_free_gpu_blocks
def append_slots(
self,
seq: Sequence,
num_lookahead_slots: int,
) -> List[Tuple[int, int]]:
block_table = self.block_tables[seq.seq_id]
block_table.append_token_ids(
token_ids=block_table.get_unseen_token_ids(seq.get_token_ids()),
num_lookahead_slots=num_lookahead_slots,
num_computed_slots=seq.data.get_num_computed_tokens(),
)
# Return any new copy-on-writes.
new_cows = self.block_allocator.clear_copy_on_writes()
return new_cows
def free(self, seq: Sequence) -> None:
seq_id = seq.seq_id
if seq_id not in self.block_tables:
# Already freed or haven't been scheduled yet.
return
# Update seq block ids with the latest access time
self._last_access_blocks_tracker.update_seq_blocks_last_access(
seq_id, self.block_tables[seq.seq_id].physical_block_ids)
# Untrack seq
self._last_access_blocks_tracker.remove_seq(seq_id)
self._computed_blocks_tracker.remove_seq(seq_id)
# Free table/blocks
self.block_tables[seq_id].free()
del self.block_tables[seq_id]
def free_cross(self, seq_group: SequenceGroup) -> None:
request_id = seq_group.request_id
if request_id not in self.cross_block_tables:
# Already freed or hasn't been scheduled yet.
return
self.cross_block_tables[request_id].free()
del self.cross_block_tables[request_id]
def can_append_slots(self, seq_group: SequenceGroup,
num_lookahead_slots: int) -> bool:
"""Determine if there is enough space in the GPU KV cache to continue
generation of the specified sequence group.
We use a worst-case heuristic: assume each touched block will require a
new allocation (either via CoW or new block). We can append slots if the
number of touched blocks is less than the number of free blocks.
"Lookahead slots" are slots that are allocated in addition to the slots
for known tokens. The contents of the lookahead slots are not defined.
This is used by speculative decoding when speculating future tokens.
"""
num_touched_blocks = 0
for seq in seq_group.get_seqs(status=SequenceStatus.RUNNING):
block_table = self.block_tables[seq.seq_id]
num_touched_blocks += (
block_table.get_num_blocks_touched_by_append_slots(
token_ids=block_table.get_unseen_token_ids(
seq.get_token_ids()),
num_lookahead_slots=num_lookahead_slots,
))
num_free_gpu_blocks = self.block_allocator.get_num_free_blocks(
Device.GPU)
return num_touched_blocks <= num_free_gpu_blocks
def append_slots(
self,
seq: Sequence,
num_lookahead_slots: int,
) -> List[Tuple[int, int]]:
block_table = self.block_tables[seq.seq_id]
block_table.append_token_ids(
token_ids=block_table.get_unseen_token_ids(seq.get_token_ids()),
num_lookahead_slots=num_lookahead_slots,
num_computed_slots=seq.data.get_num_computed_tokens(),
)
# Return any new copy-on-writes.
new_cows = self.block_allocator.clear_copy_on_writes()
return new_cows
def free(self, seq: Sequence) -> None:
seq_id = seq.seq_id
if seq_id not in self.block_tables:
# Already freed or haven't been scheduled yet.
return
# Update seq block ids with the latest access time
self._last_access_blocks_tracker.update_seq_blocks_last_access(
seq_id, self.block_tables[seq.seq_id].physical_block_ids)
# Untrack seq
self._last_access_blocks_tracker.remove_seq(seq_id)
self._computed_blocks_tracker.remove_seq(seq_id)
# Free table/blocks
self.block_tables[seq_id].free()
del self.block_tables[seq_id]
def free_cross(self, seq_group: SequenceGroup) -> None:
request_id = seq_group.request_id
if request_id not in self.cross_block_tables:
# Already freed or hasn't been scheduled yet.
return
self.cross_block_tables[request_id].free()
del self.cross_block_tables[request_id]
def get_block_table(self, seq: Sequence) -> List[int]:
block_ids = self.block_tables[seq.seq_id].physical_block_ids
return block_ids # type: ignore
def get_cross_block_table(self, seq_group: SequenceGroup) -> List[int]:
request_id = seq_group.request_id
assert request_id in self.cross_block_tables
block_ids = self.cross_block_tables[request_id].physical_block_ids
assert all(b is not None for b in block_ids)
return block_ids # type: ignore
def access_all_blocks_in_seq(self, seq: Sequence, now: float):
if self.enable_caching:
# Record the latest access time for the sequence. The actual update
# of the block ids is deferred to the sequence free(..) call, since
# only during freeing of block ids, the blocks are actually added to
# the evictor (which is when the most updated time is required)
# (This avoids expensive calls to mark_blocks_as_accessed(..))
self._last_access_blocks_tracker.update_last_access(
seq.seq_id, now)
def mark_blocks_as_computed(self, seq_group: SequenceGroup,
token_chunk_size: int):
# If prefix caching is enabled, mark immutable blocks as computed
# right after they have been scheduled (for prefill). This assumes
# the scheduler is synchronous so blocks are actually computed when
# scheduling the next batch.
self.block_allocator.mark_blocks_as_computed([])
request_id = seq_group.request_id
assert request_id in self.cross_block_tables
block_ids = self.cross_block_tables[request_id].physical_block_ids
assert all(b is not None for b in block_ids)
return block_ids # type: ignore
def access_all_blocks_in_seq(self, seq: Sequence, now: float):
if self.enable_caching:
# Record the latest access time for the sequence. The actual update
# of the block ids is deferred to the sequence free(..) call, since
# only during freeing of block ids, the blocks are actually added to
# the evictor (which is when the most updated time is required)
# (This avoids expensive calls to mark_blocks_as_accessed(..))
self._last_access_blocks_tracker.update_last_access(
seq.seq_id, now)
def mark_blocks_as_computed(self, seq_group: SequenceGroup,
token_chunk_size: int):
# If prefix caching is enabled, mark immutable blocks as computed
# right after they have been scheduled (for prefill). This assumes
# the scheduler is synchronous so blocks are actually computed when
# scheduling the next batch.
self.block_allocator.mark_blocks_as_computed([])
def get_common_computed_block_ids(
self, seqs: List[Sequence]) -> GenericSequence[int]:
"""Determine which blocks for which we skip prefill.
With prefix caching we can skip prefill for previously-generated blocks.
Currently, the attention implementation only supports skipping cached
blocks if they are a contiguous prefix of cached blocks.
This method determines which blocks can be safely skipped for all
sequences in the sequence group.
"""
computed_seq_block_ids = []
for seq in seqs:
computed_seq_block_ids.append(
self._computed_blocks_tracker.
get_cached_computed_blocks_and_update(
seq.seq_id,
self.block_tables[seq.seq_id].physical_block_ids))
# NOTE(sang): This assumes seq_block_ids doesn't contain any None.
"""Determine which blocks for which we skip prefill.
With prefix caching we can skip prefill for previously-generated blocks.
Currently, the attention implementation only supports skipping cached
blocks if they are a contiguous prefix of cached blocks.
This method determines which blocks can be safely skipped for all
sequences in the sequence group.
"""
computed_seq_block_ids = []
for seq in seqs:
computed_seq_block_ids.append(
self._computed_blocks_tracker.
get_cached_computed_blocks_and_update(
seq.seq_id,
self.block_tables[seq.seq_id].physical_block_ids))
# NOTE(sang): This assumes seq_block_ids doesn't contain any None.
return self.block_allocator.get_common_computed_block_ids(
computed_seq_block_ids) # type: ignore
@@ -583,187 +583,187 @@ class BlockSpaceManagerV2(BlockSpaceManager):
raise TypeError(f"Unsupported multimodal namespace value type {type(value)}")
def fork(self, parent_seq: Sequence, child_seq: Sequence) -> None:
if parent_seq.seq_id not in self.block_tables:
# Parent sequence has either been freed or never existed.
return
src_block_table = self.block_tables[parent_seq.seq_id]
self.block_tables[child_seq.seq_id] = src_block_table.fork()
# Track child seq
self._computed_blocks_tracker.add_seq(child_seq.seq_id)
self._last_access_blocks_tracker.add_seq(child_seq.seq_id)
def fork(self, parent_seq: Sequence, child_seq: Sequence) -> None:
if parent_seq.seq_id not in self.block_tables:
# Parent sequence has either been freed or never existed.
return
src_block_table = self.block_tables[parent_seq.seq_id]
self.block_tables[child_seq.seq_id] = src_block_table.fork()
# Track child seq
self._computed_blocks_tracker.add_seq(child_seq.seq_id)
self._last_access_blocks_tracker.add_seq(child_seq.seq_id)
def can_swap_in(self, seq_group: SequenceGroup,
num_lookahead_slots: int) -> AllocStatus:
"""Returns the AllocStatus for the given sequence_group
with num_lookahead_slots.
Args:
sequence_group (SequenceGroup): The sequence group to swap in.
num_lookahead_slots (int): Number of lookahead slots used in
speculative decoding, default to 0.
Returns:
AllocStatus: The AllocStatus for the given sequence group.
"""
"""Returns the AllocStatus for the given sequence_group
with num_lookahead_slots.
Args:
sequence_group (SequenceGroup): The sequence group to swap in.
num_lookahead_slots (int): Number of lookahead slots used in
speculative decoding, default to 0.
Returns:
AllocStatus: The AllocStatus for the given sequence group.
"""
if self.block_allocator.content_offload_enabled:
return AllocStatus.NEVER
return self._can_swap(seq_group, Device.GPU, SequenceStatus.SWAPPED,
num_lookahead_slots)
def swap_in(self, seq_group: SequenceGroup) -> List[Tuple[int, int]]:
"""Returns the block id mapping (from CPU to GPU) generated by
swapping in the given seq_group with num_lookahead_slots.
Args:
seq_group (SequenceGroup): The sequence group to swap in.
Returns:
List[Tuple[int, int]]: The mapping of swapping block from CPU
to GPU.
"""
physical_block_id_mapping = []
for seq in seq_group.get_seqs(status=SequenceStatus.SWAPPED):
blocks = self.block_tables[seq.seq_id].blocks
if len(blocks) == 0:
continue
seq_swap_mapping = self.block_allocator.swap(blocks=blocks,
src_device=Device.CPU,
dst_device=Device.GPU)
# Refresh the block ids of the table (post-swap)
self.block_tables[seq.seq_id].update(blocks)
seq_physical_block_id_mapping = {
self.block_allocator.get_physical_block_id(
Device.CPU, cpu_block_id):
self.block_allocator.get_physical_block_id(
Device.GPU, gpu_block_id)
for cpu_block_id, gpu_block_id in seq_swap_mapping.items()
}
physical_block_id_mapping.extend(
list(seq_physical_block_id_mapping.items()))
return physical_block_id_mapping
def swap_in(self, seq_group: SequenceGroup) -> List[Tuple[int, int]]:
"""Returns the block id mapping (from CPU to GPU) generated by
swapping in the given seq_group with num_lookahead_slots.
Args:
seq_group (SequenceGroup): The sequence group to swap in.
Returns:
List[Tuple[int, int]]: The mapping of swapping block from CPU
to GPU.
"""
physical_block_id_mapping = []
for seq in seq_group.get_seqs(status=SequenceStatus.SWAPPED):
blocks = self.block_tables[seq.seq_id].blocks
if len(blocks) == 0:
continue
seq_swap_mapping = self.block_allocator.swap(blocks=blocks,
src_device=Device.CPU,
dst_device=Device.GPU)
# Refresh the block ids of the table (post-swap)
self.block_tables[seq.seq_id].update(blocks)
seq_physical_block_id_mapping = {
self.block_allocator.get_physical_block_id(
Device.CPU, cpu_block_id):
self.block_allocator.get_physical_block_id(
Device.GPU, gpu_block_id)
for cpu_block_id, gpu_block_id in seq_swap_mapping.items()
}
physical_block_id_mapping.extend(
list(seq_physical_block_id_mapping.items()))
return physical_block_id_mapping
def can_swap_out(self, seq_group: SequenceGroup) -> bool:
"""Returns whether we can swap out the given sequence_group
with num_lookahead_slots.
Args:
seq_group (SequenceGroup): The sequence group to swap in.
num_lookahead_slots (int): Number of lookahead slots used in
speculative decoding, default to 0.
Returns:
bool: Whether it's possible to swap out current sequence group.
"""
"""Returns whether we can swap out the given sequence_group
with num_lookahead_slots.
Args:
seq_group (SequenceGroup): The sequence group to swap in.
num_lookahead_slots (int): Number of lookahead slots used in
speculative decoding, default to 0.
Returns:
bool: Whether it's possible to swap out current sequence group.
"""
if self.block_allocator.content_offload_enabled:
return False
alloc_status = self._can_swap(seq_group, Device.CPU,
SequenceStatus.RUNNING)
return alloc_status == AllocStatus.OK
def swap_out(self, seq_group: SequenceGroup) -> List[Tuple[int, int]]:
"""Returns the block id mapping (from GPU to CPU) generated by
swapping out the given sequence_group with num_lookahead_slots.
Args:
sequence_group (SequenceGroup): The sequence group to swap in.
Returns:
List[Tuple[int, int]]: The mapping of swapping block from
GPU to CPU.
"""
physical_block_id_mapping = []
for seq in seq_group.get_seqs(status=SequenceStatus.RUNNING):
blocks = self.block_tables[seq.seq_id].blocks
if len(blocks) == 0:
continue
seq_swap_mapping = self.block_allocator.swap(blocks=blocks,
src_device=Device.GPU,
dst_device=Device.CPU)
# Refresh the block ids of the table (post-swap)
self.block_tables[seq.seq_id].update(blocks)
seq_physical_block_id_mapping = {
self.block_allocator.get_physical_block_id(
Device.GPU, gpu_block_id):
self.block_allocator.get_physical_block_id(
Device.CPU, cpu_block_id)
for gpu_block_id, cpu_block_id in seq_swap_mapping.items()
}
physical_block_id_mapping.extend(
list(seq_physical_block_id_mapping.items()))
return physical_block_id_mapping
def get_num_free_gpu_blocks(self) -> int:
return self.block_allocator.get_num_free_blocks(Device.GPU)
def get_num_free_cpu_blocks(self) -> int:
return self.block_allocator.get_num_free_blocks(Device.CPU)
def get_prefix_cache_hit_rate(self, device: Device) -> float:
return self.block_allocator.get_prefix_cache_hit_rate(device)
def _can_swap(self,
seq_group: SequenceGroup,
device: Device,
status: SequenceStatus,
num_lookahead_slots: int = 0) -> AllocStatus:
"""Returns the AllocStatus for swapping in/out the given sequence_group
on to the 'device'.
Args:
sequence_group (SequenceGroup): The sequence group to swap in.
device (Device): device to swap the 'seq_group' on.
status (SequenceStatus): The status of sequence which is needed
for action. RUNNING for swap out and SWAPPED for swap in
num_lookahead_slots (int): Number of lookahead slots used in
speculative decoding, default to 0.
Returns:
AllocStatus: The AllocStatus for swapping in/out the given
sequence_group on to the 'device'.
"""
# First determine the number of blocks that will be touched by this
# swap. Then verify if there are available blocks in the device
# to perform the swap.
num_blocks_touched = 0
blocks: List[Block] = []
for seq in seq_group.get_seqs(status=status):
block_table = self.block_tables[seq.seq_id]
if block_table.blocks is not None:
# Compute the number blocks to touch for the tokens to be
# appended. This does NOT include the full blocks that need
# to be touched for the swap.
num_blocks_touched += \
block_table.get_num_blocks_touched_by_append_slots(
block_table.get_unseen_token_ids(seq.get_token_ids()),
num_lookahead_slots=num_lookahead_slots)
blocks.extend(block_table.blocks)
# Compute the number of full blocks to touch and add it to the
# existing count of blocks to touch.
num_blocks_touched += self.block_allocator.get_num_full_blocks_touched(
blocks, device=device)
watermark_blocks = 0
if device == Device.GPU:
watermark_blocks = self.watermark_blocks
if self.block_allocator.get_num_total_blocks(
device) < num_blocks_touched:
return AllocStatus.NEVER
elif self.block_allocator.get_num_free_blocks(
device) - num_blocks_touched >= watermark_blocks:
return AllocStatus.OK
else:
return AllocStatus.LATER
return alloc_status == AllocStatus.OK
def swap_out(self, seq_group: SequenceGroup) -> List[Tuple[int, int]]:
"""Returns the block id mapping (from GPU to CPU) generated by
swapping out the given sequence_group with num_lookahead_slots.
Args:
sequence_group (SequenceGroup): The sequence group to swap in.
Returns:
List[Tuple[int, int]]: The mapping of swapping block from
GPU to CPU.
"""
physical_block_id_mapping = []
for seq in seq_group.get_seqs(status=SequenceStatus.RUNNING):
blocks = self.block_tables[seq.seq_id].blocks
if len(blocks) == 0:
continue
seq_swap_mapping = self.block_allocator.swap(blocks=blocks,
src_device=Device.GPU,
dst_device=Device.CPU)
# Refresh the block ids of the table (post-swap)
self.block_tables[seq.seq_id].update(blocks)
seq_physical_block_id_mapping = {
self.block_allocator.get_physical_block_id(
Device.GPU, gpu_block_id):
self.block_allocator.get_physical_block_id(
Device.CPU, cpu_block_id)
for gpu_block_id, cpu_block_id in seq_swap_mapping.items()
}
physical_block_id_mapping.extend(
list(seq_physical_block_id_mapping.items()))
return physical_block_id_mapping
def get_num_free_gpu_blocks(self) -> int:
return self.block_allocator.get_num_free_blocks(Device.GPU)
def get_num_free_cpu_blocks(self) -> int:
return self.block_allocator.get_num_free_blocks(Device.CPU)
def get_prefix_cache_hit_rate(self, device: Device) -> float:
return self.block_allocator.get_prefix_cache_hit_rate(device)
def _can_swap(self,
seq_group: SequenceGroup,
device: Device,
status: SequenceStatus,
num_lookahead_slots: int = 0) -> AllocStatus:
"""Returns the AllocStatus for swapping in/out the given sequence_group
on to the 'device'.
Args:
sequence_group (SequenceGroup): The sequence group to swap in.
device (Device): device to swap the 'seq_group' on.
status (SequenceStatus): The status of sequence which is needed
for action. RUNNING for swap out and SWAPPED for swap in
num_lookahead_slots (int): Number of lookahead slots used in
speculative decoding, default to 0.
Returns:
AllocStatus: The AllocStatus for swapping in/out the given
sequence_group on to the 'device'.
"""
# First determine the number of blocks that will be touched by this
# swap. Then verify if there are available blocks in the device
# to perform the swap.
num_blocks_touched = 0
blocks: List[Block] = []
for seq in seq_group.get_seqs(status=status):
block_table = self.block_tables[seq.seq_id]
if block_table.blocks is not None:
# Compute the number blocks to touch for the tokens to be
# appended. This does NOT include the full blocks that need
# to be touched for the swap.
num_blocks_touched += \
block_table.get_num_blocks_touched_by_append_slots(
block_table.get_unseen_token_ids(seq.get_token_ids()),
num_lookahead_slots=num_lookahead_slots)
blocks.extend(block_table.blocks)
# Compute the number of full blocks to touch and add it to the
# existing count of blocks to touch.
num_blocks_touched += self.block_allocator.get_num_full_blocks_touched(
blocks, device=device)
watermark_blocks = 0
if device == Device.GPU:
watermark_blocks = self.watermark_blocks
if self.block_allocator.get_num_total_blocks(
device) < num_blocks_touched:
return AllocStatus.NEVER
elif self.block_allocator.get_num_free_blocks(
device) - num_blocks_touched >= watermark_blocks:
return AllocStatus.OK
else:
return AllocStatus.LATER

View File

@@ -7,128 +7,128 @@ from typing import Dict, List, OrderedDict, Tuple
ContentHash = bytes
class EvictionPolicy(enum.Enum):
"""Enum for eviction policy used by make_evictor to instantiate the correct
Evictor subclass.
"""Enum for eviction policy used by make_evictor to instantiate the correct
Evictor subclass.
"""
LRU = enum.auto()
FREQUENCY_AWARE = enum.auto()
class Evictor(ABC):
"""The Evictor subclasses should be used by the BlockAllocator class to
handle eviction of freed PhysicalTokenBlocks.
"""
@abstractmethod
def __init__(self):
pass
@abstractmethod
def __contains__(self, block_id: int) -> bool:
pass
@abstractmethod
class Evictor(ABC):
"""The Evictor subclasses should be used by the BlockAllocator class to
handle eviction of freed PhysicalTokenBlocks.
"""
@abstractmethod
def __init__(self):
pass
@abstractmethod
def __contains__(self, block_id: int) -> bool:
pass
@abstractmethod
def evict(self) -> Tuple[int, ContentHash]:
"""Runs the eviction algorithm and returns the evicted block's
content hash along with physical block id along with physical block id
"""
pass
@abstractmethod
"""Runs the eviction algorithm and returns the evicted block's
content hash along with physical block id along with physical block id
"""
pass
@abstractmethod
def add(self, block_id: int, content_hash: ContentHash,
num_hashed_tokens: int,
last_accessed: float):
"""Adds block to the evictor, making it a candidate for eviction"""
pass
@abstractmethod
def update(self, block_id: int, last_accessed: float):
"""Update corresponding block's access time in metadata"""
pass
@abstractmethod
def remove(self, block_id: int):
"""Remove a given block id from the cache."""
pass
@property
@abstractmethod
def num_blocks(self) -> int:
pass
class BlockMetaData():
"""Data structure for storing key data describe cached block, so that
evitor could use to make its decision which one to choose for eviction
Here we use physical block id as the dict key, as there maybe several
blocks with the same content hash, but their physical id is unique.
"""
"""Adds block to the evictor, making it a candidate for eviction"""
pass
@abstractmethod
def update(self, block_id: int, last_accessed: float):
"""Update corresponding block's access time in metadata"""
pass
@abstractmethod
def remove(self, block_id: int):
"""Remove a given block id from the cache."""
pass
@property
@abstractmethod
def num_blocks(self) -> int:
pass
class BlockMetaData():
"""Data structure for storing key data describe cached block, so that
evitor could use to make its decision which one to choose for eviction
Here we use physical block id as the dict key, as there maybe several
blocks with the same content hash, but their physical id is unique.
"""
def __init__(self, content_hash: ContentHash, num_hashed_tokens: int,
last_accessed: float):
self.content_hash = content_hash
self.num_hashed_tokens = num_hashed_tokens
self.last_accessed = last_accessed
class LRUEvictor(Evictor):
"""Evicts in a least-recently-used order using the last_accessed timestamp
that's recorded in the PhysicalTokenBlock. If there are multiple blocks with
the same last_accessed time, then the one with the largest num_hashed_tokens
will be evicted. If two blocks each have the lowest last_accessed time and
highest num_hashed_tokens value, then one will be chose arbitrarily
"""
def __init__(self):
self.free_table: OrderedDict[int, BlockMetaData] = OrderedDict()
def __contains__(self, block_id: int) -> bool:
return block_id in self.free_table
self.content_hash = content_hash
self.num_hashed_tokens = num_hashed_tokens
self.last_accessed = last_accessed
class LRUEvictor(Evictor):
"""Evicts in a least-recently-used order using the last_accessed timestamp
that's recorded in the PhysicalTokenBlock. If there are multiple blocks with
the same last_accessed time, then the one with the largest num_hashed_tokens
will be evicted. If two blocks each have the lowest last_accessed time and
highest num_hashed_tokens value, then one will be chose arbitrarily
"""
def __init__(self):
self.free_table: OrderedDict[int, BlockMetaData] = OrderedDict()
def __contains__(self, block_id: int) -> bool:
return block_id in self.free_table
def evict(self) -> Tuple[int, ContentHash]:
if len(self.free_table) == 0:
raise ValueError("No usable cache memory left")
evicted_block, evicted_block_id = None, None
# The blocks with the lowest timestamps should be placed consecutively
# at the start of OrderedDict. Loop through all these blocks to
# find the one with maximum number of hashed tokens.
for _id, block in self.free_table.items():
if evicted_block is None:
evicted_block, evicted_block_id = block, _id
continue
if evicted_block.last_accessed < block.last_accessed:
break
if evicted_block.num_hashed_tokens < block.num_hashed_tokens:
evicted_block, evicted_block_id = block, _id
assert evicted_block is not None
assert evicted_block_id is not None
self.free_table.pop(evicted_block_id)
return evicted_block_id, evicted_block.content_hash
if len(self.free_table) == 0:
raise ValueError("No usable cache memory left")
evicted_block, evicted_block_id = None, None
# The blocks with the lowest timestamps should be placed consecutively
# at the start of OrderedDict. Loop through all these blocks to
# find the one with maximum number of hashed tokens.
for _id, block in self.free_table.items():
if evicted_block is None:
evicted_block, evicted_block_id = block, _id
continue
if evicted_block.last_accessed < block.last_accessed:
break
if evicted_block.num_hashed_tokens < block.num_hashed_tokens:
evicted_block, evicted_block_id = block, _id
assert evicted_block is not None
assert evicted_block_id is not None
self.free_table.pop(evicted_block_id)
return evicted_block_id, evicted_block.content_hash
def add(self, block_id: int, content_hash: ContentHash,
num_hashed_tokens: int,
last_accessed: float):
self.free_table[block_id] = BlockMetaData(content_hash,
num_hashed_tokens,
last_accessed)
def update(self, block_id: int, last_accessed: float):
self.free_table[block_id].last_accessed = last_accessed
def remove(self, block_id: int):
if block_id not in self.free_table:
raise ValueError(
"Attempting to remove block that's not in the evictor")
self.free_table.pop(block_id)
@property
self.free_table[block_id] = BlockMetaData(content_hash,
num_hashed_tokens,
last_accessed)
def update(self, block_id: int, last_accessed: float):
self.free_table[block_id].last_accessed = last_accessed
def remove(self, block_id: int):
if block_id not in self.free_table:
raise ValueError(
"Attempting to remove block that's not in the evictor")
self.free_table.pop(block_id)
@property
def num_blocks(self) -> int:
return len(self.free_table)
@@ -261,8 +261,8 @@ def eviction_policy_from_env(
raise ValueError(
"BI100_KV_EVICTION_POLICY must be one of: frequency, lru")
return policies[value]
def make_evictor(eviction_policy: EvictionPolicy) -> Evictor:
if eviction_policy == EvictionPolicy.LRU:
return LRUEvictor()