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AstrAI/tests/extension/test_swiglu_dispatch.py
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ViperEkura 7540acb43e perf: dispatch linear gemv by decode batch size and unify extension style
- replace the per-shape auto tables in the linear backend with an M-banded rule (M in [2,4] on compute capability 8.0+) that measured at the HBM bandwidth floor across every family, and fold the capability check into the capable guard
- drop the unreachable swiglu auto shape-table machinery so both backends share one env-mode ladder via the new dispatch.env_mode helper
- add __all__ across extension modules, name the rotary registration records, and unify typing to the typing-module style
- rewrite test_linear_dispatch.py around behavioral routing assertions and document the M-banded policy in the developer docs
- Benchmark: L20 SM89, Python dispatch overhead 2.9us to 1.5us, auto now covers every projection shape at M in [2,4].
2026-09-03 07:23:13 +08:00

98 lines
3.6 KiB
Python

import logging
import pytest
import torch
import torch.nn.functional as F
from astrai.extension import is_available, swiglu
from astrai.model.components.mlp import MLP
SWIGLU_AVAILABLE = (
torch.cuda.is_available()
and is_available("bf16_swiglu")
and torch.cuda.get_device_capability() >= (8, 0)
)
skip_no_swiglu = pytest.mark.skipif(
not SWIGLU_AVAILABLE,
reason="BF16 SwiGLU requires a built kernel and compute capability 8.0+",
)
def reference_swiglu(x, up_weight, gate_weight):
return F.linear(x, up_weight) * F.silu(F.linear(x, gate_weight))
def test_cpu_and_training_calls_fall_back_with_gradients(monkeypatch):
monkeypatch.setenv("ASTRAI_SWIGLU", "1")
x = torch.randn(2, 8, requires_grad=True)
up_weight = torch.randn(4, 8, requires_grad=True)
gate_weight = torch.randn(4, 8, requires_grad=True)
actual = swiglu(x, up_weight, gate_weight)
expected = reference_swiglu(x, up_weight, gate_weight)
torch.testing.assert_close(actual, expected)
actual.sum().backward()
assert x.grad is not None
assert up_weight.grad is not None
assert gate_weight.grad is not None
def test_invalid_mode_warns_and_uses_auto(monkeypatch, caplog):
monkeypatch.setenv("ASTRAI_SWIGLU", "invalid-test-mode")
with caplog.at_level(logging.WARNING):
actual = swiglu(torch.randn(2, 8), torch.randn(4, 8), torch.randn(4, 8))
assert actual.shape == (2, 4)
assert "using auto" in caplog.text
def test_mlp_routes_through_swiglu_backend(monkeypatch):
sentinel = torch.randn(2, 4)
def fake_swiglu(x, up_weight, gate_weight):
assert x.shape == (2, 3)
assert up_weight.shape == gate_weight.shape == (4, 3)
return sentinel
monkeypatch.setattr("astrai.model.components.mlp.swiglu", fake_swiglu)
layer = MLP(3, 4)
output = layer(torch.randn(2, 3))
assert output["hidden_states"].shape == (2, 3)
@skip_no_swiglu
def test_mode_zero_disables_fused_kernel(monkeypatch):
monkeypatch.setenv("ASTRAI_SWIGLU", "0")
x = torch.randn(4, 1536, device="cuda", dtype=torch.bfloat16) * 0.1
up_weight = torch.randn(6912, 1536, device="cuda", dtype=torch.bfloat16) * 0.02
gate_weight = torch.randn_like(up_weight) * 0.02
with torch.no_grad():
actual = swiglu(x, up_weight, gate_weight)
expected = reference_swiglu(x, up_weight, gate_weight)
torch.testing.assert_close(actual, expected)
@skip_no_swiglu
def test_mode_one_forces_supported_shape(monkeypatch):
monkeypatch.setenv("ASTRAI_SWIGLU", "1")
x = torch.randn(4, 1536, device="cuda", dtype=torch.bfloat16) * 0.1
up_weight = torch.randn(6912, 1536, device="cuda", dtype=torch.bfloat16) * 0.02
gate_weight = torch.randn_like(up_weight) * 0.02
with torch.no_grad():
actual = swiglu(x, up_weight, gate_weight)
expected = reference_swiglu(x, up_weight, gate_weight)
torch.testing.assert_close(actual, expected, rtol=0.03, atol=0.01)
@skip_no_swiglu
def test_auto_uses_unfused_chain_until_shape_is_qualified(monkeypatch):
# The fusion table is empty, so auto keeps the unfused linear-backend
# chain. The linear backend may still dispatch its own GEMV for M=4,
# hence the relaxed tolerance versus the pure-torch reference.
monkeypatch.setenv("ASTRAI_SWIGLU", "auto")
x = torch.randn(4, 1536, device="cuda", dtype=torch.bfloat16)
up_weight = torch.randn(6912, 1536, device="cuda", dtype=torch.bfloat16)
gate_weight = torch.randn_like(up_weight)
with torch.no_grad():
actual = swiglu(x, up_weight, gate_weight)
expected = reference_swiglu(x, up_weight, gate_weight)
torch.testing.assert_close(actual, expected, rtol=0.03, atol=0.1)