SolitaryThinker
db866dfb04
Sweep all 296 v2 modules: simplify verbose docstrings/comments and remove 376 dangling "(design_vN §X)" citations to the now-deleted design docs (v2/README.md is the source of truth). Comment/docstring-only — AST-verified code-identical; the CPU suite holds at 237 passed / 5 pre-existing. Also applies yapf + ruff --fix auto-fixes (import ordering, forward-ref annotation de-quoting under `from __future__ import annotations`; behavior- neutral, suite-confirmed) and adds the legitimate domain terms mot/clen/te to the codespell ignore-list. Remaining ruff (24) + mypy (68 no-untyped-call) findings are pre-existing v2 debt, untouched here.
57 lines
2.0 KiB
Python
57 lines
2.0 KiB
Python
"""FakeDeviceMesh — a torchtitan-style ParallelDims builder, CPU-testable.
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On a GPU box this compiles to ``torch.distributed.device_mesh.DeviceMesh``. Here it is a
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pure-Python mesh of rank tuples so topology logic is unit-tested without GPUs.
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Degree-one axes exist as trivial groups so component code needs no special cases.
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"""
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from __future__ import annotations
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from itertools import product
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from v2.parallel.plan import ParallelPlan
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from v2.parallel.validation import validate_plan
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class FakeDeviceMesh:
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def __init__(self, plan: ParallelPlan):
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self.plan = plan
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self.order = plan.mesh_order or list(plan.axes.keys())
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self.shape = tuple(plan.degree(a) for a in self.order)
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self.world_size = plan.world_size()
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def group_ranks(self, axis: str) -> list[list[int]]:
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"""All collective groups along one axis (each is a list of global ranks)."""
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if axis not in self.order:
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return [[0]] # degree-one trivial group
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axis_idx = self.order.index(axis)
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groups: list[list[int]] = []
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ranges = [range(d) for d in self.shape]
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seen: set[tuple] = set()
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for coord in product(*ranges):
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key = coord[:axis_idx] + coord[axis_idx + 1:]
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if key in seen:
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continue
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seen.add(key)
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group = []
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for i in range(self.shape[axis_idx]):
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c = list(coord)
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c[axis_idx] = i
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group.append(self._coord_to_rank(tuple(c)))
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groups.append(group)
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return groups
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def _coord_to_rank(self, coord: tuple[int, ...]) -> int:
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rank = 0
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for c, d in zip(coord, self.shape, strict=False):
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rank = rank * d + c
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return rank
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def __repr__(self) -> str:
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return f"FakeDeviceMesh(order={self.order}, shape={self.shape}, world={self.world_size})"
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def build_mesh(plan: ParallelPlan, card=None, **kw) -> FakeDeviceMesh:
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validate_plan(plan, card=card, **kw)
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return FakeDeviceMesh(plan)
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