unsloth/tests/test_attention_implementation.py
Datta Nimmaturi ed1e3929ad
fix(gpt-oss): prefer flex attention over sdpa (#5701)
* fix(gpt-oss): prefer flex attention over sdpa

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* fix(gpt-oss): use eager config for unsupported backends

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-05-22 08:38:38 -07:00

56 lines
1.4 KiB
Python

from types import SimpleNamespace
import unsloth # noqa: F401
from transformers.utils import import_utils
from unsloth.models import _utils
class SupportsFlexAndSdpa:
_supports_flash_attn_2 = True
_supports_flex_attn = True
_supports_sdpa = True
def _config(model_type, **kwargs):
values = {"model_type": model_type, "attention_dropout": 0}
values.update(kwargs)
return SimpleNamespace(**values)
def _set_flex_available(monkeypatch, available):
monkeypatch.setenv("UNSLOTH_ENABLE_FLEX_ATTENTION", "1")
monkeypatch.setattr(
import_utils,
"is_torch_flex_attn_available",
lambda: available,
raising = False,
)
def test_gpt_oss_uses_eager_instead_of_flash_flex_or_sdpa(monkeypatch):
_set_flex_available(monkeypatch, True)
config = _config("gpt_oss")
impl = _utils.resolve_attention_implementation(
SupportsFlexAndSdpa,
config,
supports_sdpa = True,
)
assert impl == "eager"
assert config._attn_implementation == "eager"
def test_gpt_oss_falls_back_to_eager_when_flex_unavailable(monkeypatch):
_set_flex_available(monkeypatch, False)
config = _config("gpt_oss")
impl = _utils.resolve_attention_implementation(
SupportsFlexAndSdpa,
config,
supports_sdpa = True,
)
assert impl == "eager"
assert config._attn_implementation == "eager"