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sglang/python/sglang/srt/mem_cache/memory_pool.py

252 lines
7.7 KiB
Python

"""
Copyright 2023-2024 SGLang Team
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
"""Memory pool."""
import logging
from abc import ABC, abstractmethod
from typing import List, Tuple, Union
import torch
logger = logging.getLogger(__name__)
class ReqToTokenPool:
"""A memory pool that maps a request to its token locations."""
def __init__(self, size: int, max_context_len: int, device: str):
self.size = size
self.free_slots = list(range(size))
self.req_to_token = torch.empty(
(size, max_context_len), dtype=torch.int32, device=device
)
def alloc(self, need_size: int) -> List[int]:
if need_size > len(self.free_slots):
return None
select_index = self.free_slots[:need_size]
self.free_slots = self.free_slots[need_size:]
return select_index
def free(self, free_index: Union[int, List[int]]):
if isinstance(free_index, (int,)):
self.free_slots.append(free_index)
else:
self.free_slots.extend(free_index)
def clear(self):
self.free_slots = list(range(self.size))
class BaseTokenToKVPool(ABC):
"""A memory pool that maps a token to its kv cache locations"""
def __init__(
self,
size: int,
dtype: torch.dtype,
):
self.size = size
self.dtype = dtype
if dtype == torch.float8_e5m2:
# NOTE: Store as torch.uint8 because Tensor index_put is not implemented for torch.float8_e5m2
self.store_dtype = torch.uint8
else:
self.store_dtype = dtype
# We also add one slot. This slot is used for writing dummy output from padded tokens.
self.mem_state = torch.ones((self.size + 1,), dtype=torch.bool, device="cuda")
# Prefetch buffer
self.prefetch_buffer = torch.empty(0, device="cuda", dtype=torch.int32)
self.prefetch_chunk_size = 512
self.can_use_mem_size = self.size
self.clear()
def available_size(self):
return self.can_use_mem_size + len(self.prefetch_buffer)
def alloc(self, need_size: int):
buffer_len = len(self.prefetch_buffer)
if need_size <= buffer_len:
select_index = self.prefetch_buffer[:need_size]
self.prefetch_buffer = self.prefetch_buffer[need_size:]
return select_index
addition_size = need_size - buffer_len
alloc_size = max(addition_size, self.prefetch_chunk_size)
select_index = (
torch.nonzero(self.mem_state).squeeze(1)[:alloc_size].to(torch.int32)
)
if select_index.shape[0] < addition_size:
return None
self.mem_state[select_index] = False
self.can_use_mem_size -= len(select_index)
self.prefetch_buffer = torch.cat((self.prefetch_buffer, select_index))
ret_index = self.prefetch_buffer[:need_size]
self.prefetch_buffer = self.prefetch_buffer[need_size:]
return ret_index
def free(self, free_index: torch.Tensor):
self.mem_state[free_index] = True
self.can_use_mem_size += len(free_index)
def clear(self):
self.prefetch_buffer = torch.empty(0, device="cuda", dtype=torch.int32)
self.mem_state.fill_(True)
self.can_use_mem_size = self.size
# We also add one slot. This slot is used for writing dummy output from padded tokens.
self.mem_state[0] = False
@abstractmethod
def get_key_buffer(self, layer_id: int) -> torch.Tensor:
raise NotImplementedError()
@abstractmethod
def get_value_buffer(self, layer_id: int) -> torch.Tensor:
raise NotImplementedError()
@abstractmethod
def get_kv_buffer(self, layer_id: int) -> Tuple[torch.Tensor, torch.Tensor]:
raise NotImplementedError()
@abstractmethod
def set_kv_buffer(
self,
layer_id: int,
loc: torch.Tensor,
cache_k: torch.Tensor,
cache_v: torch.Tensor,
) -> None:
raise NotImplementedError()
class MHATokenToKVPool(BaseTokenToKVPool):
def __init__(
self,
size: int,
dtype: torch.dtype,
head_num: int,
head_dim: int,
layer_num: int,
):
super().__init__(size, dtype)
# [size, head_num, head_dim] for each layer
self.k_buffer = [
torch.empty(
(size + 1, head_num, head_dim), dtype=self.store_dtype, device="cuda"
)
for _ in range(layer_num)
]
self.v_buffer = [
torch.empty(
(size + 1, head_num, head_dim), dtype=self.store_dtype, device="cuda"
)
for _ in range(layer_num)
]
def get_key_buffer(self, layer_id: int):
if self.store_dtype != self.dtype:
return self.k_buffer[layer_id].view(self.dtype)
return self.k_buffer[layer_id]
def get_value_buffer(self, layer_id: int):
if self.store_dtype != self.dtype:
return self.v_buffer[layer_id].view(self.dtype)
return self.v_buffer[layer_id]
def get_kv_buffer(self, layer_id: int):
return self.get_key_buffer(layer_id), self.get_value_buffer(layer_id)
def set_kv_buffer(
self,
layer_id: int,
loc: torch.Tensor,
cache_k: torch.Tensor,
cache_v: torch.Tensor,
):
if cache_k.dtype != self.dtype:
cache_k = cache_k.to(self.dtype)
if cache_v.dtype != self.dtype:
cache_v = cache_v.to(self.dtype)
if self.store_dtype != self.dtype:
self.k_buffer[layer_id][loc] = cache_k.view(self.store_dtype)
self.v_buffer[layer_id][loc] = cache_v.view(self.store_dtype)
else:
self.k_buffer[layer_id][loc] = cache_k
self.v_buffer[layer_id][loc] = cache_v
class MLATokenToKVPool(BaseTokenToKVPool):
def __init__(
self,
size: int,
dtype: torch.dtype,
kv_lora_rank: int,
qk_rope_head_dim: int,
layer_num: int,
):
super().__init__(size, dtype)
self.kv_lora_rank = kv_lora_rank
self.kv_buffer = [
torch.empty(
(size + 1, 1, kv_lora_rank + qk_rope_head_dim),
dtype=self.store_dtype,
device="cuda",
)
for _ in range(layer_num)
]
def get_key_buffer(self, layer_id: int):
if self.store_dtype != self.dtype:
return self.kv_buffer[layer_id].view(self.dtype)
return self.kv_buffer[layer_id]
def get_value_buffer(self, layer_id: int):
if self.store_dtype != self.dtype:
return self.kv_buffer[layer_id][..., : self.kv_lora_rank].view(self.dtype)
return self.kv_buffer[layer_id][..., : self.kv_lora_rank]
def get_kv_buffer(self, layer_id: int):
return self.get_key_buffer(layer_id), self.get_value_buffer(layer_id)
def set_kv_buffer(
self,
layer_id: int,
loc: torch.Tensor,
cache_k: torch.Tensor,
cache_v: torch.Tensor,
):
if cache_k.dtype != self.dtype:
cache_k = cache_k.to(self.dtype)
if self.store_dtype != self.dtype:
self.kv_buffer[layer_id][loc] = cache_k.view(self.store_dtype)
else:
self.kv_buffer[layer_id][loc] = cache_k