Files
enginex-mlu370-vllm/vllm-v0.6.2/vllm_mlu/vllm_mlu/attention/selector.py
2026-02-04 17:22:39 +08:00

304 lines
12 KiB
Python

import enum
import os
from contextlib import contextmanager
from functools import lru_cache
from typing import Generator, Optional, Type
import torch
import vllm.envs as envs
from vllm.attention.backends.abstract import AttentionBackend
from vllm.attention.selector import get_global_forced_attn_backend
from vllm.logger import init_logger
from vllm.platforms import current_platform
from vllm.utils import STR_BACKEND_ENV_VAR
from vllm_mlu._mlu_utils import USE_PAGED
from vllm_mlu.mlu_hijack_utils import MluHijackObject
from vllm.attention.selector import _Backend, backend_name_to_enum
from vllm.attention import selector
logger = init_logger(__name__)
'''
=============================
Modify by vllm_mlu
=============================
@brief: Add MLU_MLA_FLASH_ATTN for deepseekv2 MLA.
'''
_Backend.MLU_MLA_FLASH_ATTN = enum.auto()
'''
==================
End of MLU Hijack
==================
'''
'''
=============================
Modify by vllm_mlu
=============================
@brief: add a arg use_mla for function get_attn_backend, _cached_get_attn_backend,
which_attn_to_use
'''
'''
==================
End of MLU Hijack
==================
'''
def vllm__attention__selector__get_attn_backend(
head_size: int,
dtype: torch.dtype,
kv_cache_dtype: Optional[str],
block_size: int,
is_attention_free: bool,
is_blocksparse: bool = False,
use_mla: bool = False,
) -> Type[AttentionBackend]:
"""Selects which attention backend to use and lazily imports it."""
# Accessing envs.* behind an @lru_cache decorator can cause the wrong
# value to be returned from the cache if the value changes between calls.
# To avoid this, we read envs.VLLM_USE_V1 here and pass it explicitly to the
# private function.
return vllm__attention__selector___cached_get_attn_backend(
head_size=head_size,
dtype=dtype,
kv_cache_dtype=kv_cache_dtype,
block_size=block_size,
is_attention_free=is_attention_free,
is_blocksparse=is_blocksparse,
use_v1=envs.VLLM_USE_V1,
use_mla=use_mla,
)
@lru_cache(maxsize=None)
def vllm__attention__selector___cached_get_attn_backend(
head_size: int,
dtype: torch.dtype,
kv_cache_dtype: Optional[str],
block_size: int,
is_attention_free: bool,
is_blocksparse: bool = False,
use_v1: bool = False,
use_mla: bool = False,
) -> Type[AttentionBackend]:
if is_blocksparse:
logger.info("Using BlocksparseFlashAttention backend.")
from vllm.attention.backends.blocksparse_attn import (
BlocksparseFlashAttentionBackend)
return BlocksparseFlashAttentionBackend
backend = vllm__attention__selector__which_attn_to_use(head_size, dtype, kv_cache_dtype, block_size,
is_attention_free, use_v1, use_mla)
if backend == _Backend.FLASH_ATTN:
logger.info("Using Flash Attention backend.")
from vllm.attention.backends.flash_attn import ( # noqa: F401
FlashAttentionBackend)
return FlashAttentionBackend
if backend == _Backend.FLASH_ATTN_VLLM_V1:
from vllm.v1.attention.backends.flash_attn import ( # noqa: F401
FlashAttentionBackend as FlashAttentionBackendV1)
return FlashAttentionBackendV1
if backend == _Backend.XFORMERS:
logger.info("Using XFormers backend.")
from vllm.attention.backends.xformers import ( # noqa: F401
XFormersBackend)
return XFormersBackend
elif backend == _Backend.ROCM_FLASH:
logger.info("Using ROCmFlashAttention backend.")
from vllm.attention.backends.rocm_flash_attn import ( # noqa: F401
ROCmFlashAttentionBackend)
return ROCmFlashAttentionBackend
elif backend == _Backend.TORCH_SDPA:
assert current_platform.is_cpu(), RuntimeError(
"Torch SDPA backend is only used for the CPU device.")
logger.info("Using Torch SDPA backend.")
from vllm.attention.backends.torch_sdpa import TorchSDPABackend
return TorchSDPABackend
elif backend == _Backend.OPENVINO:
logger.info("Using OpenVINO Attention backend.")
from vllm.attention.backends.openvino import OpenVINOAttentionBackend
return OpenVINOAttentionBackend
elif backend == _Backend.IPEX:
assert current_platform.is_xpu(), RuntimeError(
"IPEX attention backend is only used for the XPU device.")
logger.info("Using IPEX attention backend.")
from vllm.attention.backends.ipex_attn import IpexAttnBackend
return IpexAttnBackend
elif backend == _Backend.FLASHINFER:
logger.info("Using Flashinfer backend.")
from vllm.attention.backends.flashinfer import FlashInferBackend
return FlashInferBackend
elif backend == _Backend.HPU_ATTN:
logger.info("Using HPUAttention backend.")
from vllm.attention.backends.hpu_attn import HPUAttentionBackend
return HPUAttentionBackend
elif backend == _Backend.PALLAS:
logger.info("Using Pallas backend.")
from vllm.attention.backends.pallas import PallasAttentionBackend
return PallasAttentionBackend
elif backend == _Backend.MLU_MLA_FLASH_ATTN:
logger.info("Using MLUFlashAttention backend.")
from vllm_mlu.attention.backends.mlu_attn import MLUMLAFlashAttentionBackend
return MLUMLAFlashAttentionBackend
elif backend == _Backend.MLU_FLASH_ATTN:
logger.info("Using MLUFlashAttention backend.")
from vllm.attention.backends.mlu_attn import MLUFlashAttentionBackend
return MLUFlashAttentionBackend
elif backend == _Backend.NO_ATTENTION:
from vllm.attention.backends.placeholder_attn import (
PlaceholderAttentionBackend)
return PlaceholderAttentionBackend
else:
raise ValueError("Invalid attention backend.")
def vllm__attention__selector__which_attn_to_use(head_size: int,
dtype: torch.dtype,
kv_cache_dtype: Optional[str],
block_size: int,
is_attention_free: bool,
use_v1: bool = False,
use_mla: bool = False) -> _Backend:
"""Returns which flash attention backend to use."""
# Default case.
selected_backend = _Backend.FLASH_ATTN
# If there are no attention layers (e.g. we are running Mamba),
# use the placeholder NO_ATTENTION
if is_attention_free:
return _Backend.NO_ATTENTION
# Check whether a particular choice of backend was
# previously forced.
#
# THIS SELECTION OVERRIDES THE VLLM_ATTENTION_BACKEND
# ENVIRONMENT VARIABLE.
backend_by_global_setting: Optional[_Backend] = (
get_global_forced_attn_backend())
if backend_by_global_setting is not None:
selected_backend = backend_by_global_setting
else:
# Check the environment variable and override if specified
backend_by_env_var: Optional[str] = envs.VLLM_ATTENTION_BACKEND
if backend_by_env_var is not None:
selected_backend = backend_name_to_enum(backend_by_env_var)
if current_platform.is_cpu():
if selected_backend != _Backend.TORCH_SDPA:
logger.info("Cannot use %s backend on CPU.", selected_backend)
return _Backend.TORCH_SDPA
if current_platform.is_openvino():
if selected_backend != _Backend.OPENVINO:
logger.info("Cannot use %s backend on OpenVINO.", selected_backend)
return _Backend.OPENVINO
if current_platform.is_xpu():
if selected_backend != _Backend.IPEX:
logger.info("Cannot use %s backend on XPU.", selected_backend)
return _Backend.IPEX
if current_platform.is_tpu():
if selected_backend != _Backend.PALLAS:
logger.info("Cannot use %s backend on TPU.", selected_backend)
return _Backend.PALLAS
if current_platform.is_mlu():
'''
=============================
Modify by vllm_mlu
=============================
@brief: Add MLU_MLA_FLASH_ATTN for deepseekv2 MLA.
'''
'''
==================
End of MLU Hijack
==================
'''
if use_mla:
return _Backend.MLU_MLA_FLASH_ATTN
if selected_backend != _Backend.MLU_FLASH_ATTN:
logger.debug("Cannot use %s backend on MLU.", selected_backend)
return _Backend.MLU_FLASH_ATTN
if current_platform.is_rocm():
# AMD GPUs.
selected_backend = (_Backend.ROCM_FLASH if selected_backend
== _Backend.FLASH_ATTN else selected_backend)
if selected_backend == _Backend.ROCM_FLASH:
if not current_platform.has_device_capability(90):
# not Instinct series GPUs.
logger.info("flash_attn is not supported on NAVI GPUs.")
else:
logger.info("%s is not supported in AMD GPUs.", selected_backend)
return _Backend.ROCM_FLASH
if current_platform.is_hpu():
return _Backend.HPU_ATTN
if use_v1:
return _Backend.FLASH_ATTN_VLLM_V1
# FlashAttn in NVIDIA GPUs.
if selected_backend == _Backend.FLASH_ATTN:
if not current_platform.has_device_capability(80):
# Volta and Turing NVIDIA GPUs.
logger.info(
"Cannot use FlashAttention-2 backend for Volta and Turing "
"GPUs.")
selected_backend = _Backend.XFORMERS
elif dtype not in (torch.float16, torch.bfloat16):
logger.info(
"Cannot use FlashAttention-2 backend for dtype other than "
"torch.float16 or torch.bfloat16.")
selected_backend = _Backend.XFORMERS
elif kv_cache_dtype is not None and kv_cache_dtype.startswith("fp8"):
logger.info(
"Cannot use FlashAttention-2 backend for FP8 KV cache.")
logger.warning(
"Please use FlashInfer backend with FP8 KV Cache for "
"better performance by setting environment variable "
"VLLM_ATTENTION_BACKEND=FLASHINFER")
selected_backend = _Backend.XFORMERS
elif block_size % 16 != 0:
logger.info(
"Cannot use FlashAttention-2 backend for block size not "
"divisible by 16.")
selected_backend = _Backend.XFORMERS
# FlashAttn is valid for the model, checking if the package is installed.
if selected_backend == _Backend.FLASH_ATTN:
try:
import vllm.vllm_flash_attn # noqa: F401
from vllm.attention.backends.flash_attn import ( # noqa: F401
FlashAttentionBackend)
supported_sizes = FlashAttentionBackend.get_supported_head_sizes()
if head_size not in supported_sizes:
logger.info(
"Cannot use FlashAttention-2 backend for head size %d.",
head_size)
selected_backend = _Backend.XFORMERS
except ImportError:
logger.info(
"Cannot use FlashAttention-2 backend because the "
"vllm.vllm_flash_attn package is not found. "
"Make sure that vllm_flash_attn was built and installed "
"(on by default).")
selected_backend = _Backend.XFORMERS
return selected_backend
MluHijackObject.apply_hijack(selector,
selector.get_attn_backend,
vllm__attention__selector__get_attn_backend)
MluHijackObject.apply_hijack(selector,
selector._cached_get_attn_backend,
vllm__attention__selector___cached_get_attn_backend)
MluHijackObject.apply_hijack(selector,
selector.which_attn_to_use,
vllm__attention__selector__which_attn_to_use)