SYLARandlishunyang12
1c2a81f6d8
Signed-off-by: lishunyang12 <lishunyang03@gmail.com> Signed-off-by: lishunyang12 <lishunyang12@163.com> Co-authored-by: lishunyang12 <lishunyang03@gmail.com>
75 lines
3.2 KiB
Python
75 lines
3.2 KiB
Python
# SPDX-License-Identifier: Apache-2.0
|
|
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
|
|
"""Declarative OffloadPlan for distributed layerwise offload.
|
|
|
|
Models declare this as a class attribute ``_offload_plan`` on the
|
|
pipeline class. When present, the offloader uses it instead of
|
|
heuristic block discovery.
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
from dataclasses import dataclass, field
|
|
|
|
from torch import nn
|
|
|
|
|
|
@dataclass(frozen=True)
|
|
class OffloadPlan:
|
|
"""Optional declarative metadata for distributed layerwise offload.
|
|
|
|
Models declare this as a class attribute ``_offload_plan`` on the
|
|
pipeline class. When present, the offloader uses it instead of
|
|
heuristic block discovery, making it easier to support new models
|
|
without offload-specific logic in constructor or forward code.
|
|
|
|
If not declared, the offloader falls back to:
|
|
1. ``_layerwise_offload_blocks_attrs`` on each DiT module class.
|
|
2. Heuristic search for ``layers`` / ``blocks`` / ``h`` attributes.
|
|
|
|
Attributes:
|
|
block_attrs: Maps DiT path → tuple of block-list attribute names.
|
|
e.g. ``{"transformer": ("gen_layers",),
|
|
"transformer.language_model": ("layers",)}``
|
|
offload_submodules: Maps child name → block-list attribute name,
|
|
for large non-DiT submodules within a DiT that should be
|
|
independently offloaded with their own hooks.
|
|
e.g. ``{"context_encoder": "layers"}``
|
|
resident_dit_paths: DiT paths whose leading blocks may be kept on the
|
|
device when ``dlo_resident_layers`` is nonzero. Keeping this
|
|
model-declared avoids applying a consumer-GPU tuning knob to
|
|
auxiliary or dual DiTs unintentionally.
|
|
encoder_block_attrs: Maps encoder paths to rank-local block-list paths.
|
|
These blocks are streamed with ordinary layerwise hooks, never
|
|
with the DiT AllGather group.
|
|
"""
|
|
|
|
on_demand_component_paths: frozenset[str] = field(default_factory=frozenset)
|
|
|
|
block_attrs: dict[str, tuple[str, ...]] = field(default_factory=dict)
|
|
offload_submodules: dict[str, str] = field(default_factory=dict)
|
|
resident_dit_paths: frozenset[str] = field(default_factory=frozenset)
|
|
encoder_block_attrs: dict[str, tuple[str, ...]] = field(default_factory=dict)
|
|
|
|
|
|
def get_offload_plan(pipeline: nn.Module) -> OffloadPlan | None:
|
|
"""Retrieve the OffloadPlan declared by the pipeline, if any."""
|
|
return getattr(pipeline, "_offload_plan", None)
|
|
|
|
|
|
def supports_mmap_loading(pipeline: nn.Module) -> bool:
|
|
"""Whether the pipeline supports mmap weight loading.
|
|
|
|
A pipeline supports mmap if any module defines ``_remap_ckpt_key``,
|
|
which maps checkpoint keys to model parameter names. Models without
|
|
this method must use the regular ``load_weights()`` path.
|
|
|
|
This check is shared between ``diffusers_loader.py`` (to decide whether
|
|
to skip ``load_weights``) and ``DistributedLayerwiseOffloadBackend.enable()``
|
|
(to decide whether to call ``_load_weights_via_mmap``), ensuring both
|
|
paths use the same gate condition.
|
|
"""
|
|
return bool(getattr(pipeline, "_supports_mmap_loading", True)) and any(
|
|
callable(getattr(type(m), "_remap_ckpt_key", None)) for m in pipeline.modules()
|
|
)
|