sglang0.4.5.post1/sgl-kernel/tests/test_moe_topk_softmax.py

54 lines
1.6 KiB
Python

import itertools
import pytest
import torch
from sgl_kernel import topk_softmax
@pytest.mark.parametrize(
"num_tokens, num_experts, topk",
list(
itertools.product(
[1, 16, 128, 512, 1024, 2048], # num_tokens
[4, 8, 16, 32, 64, 128, 256], # num_experts
[1, 2, 4], # topk
)
),
)
def test_topk_softmax(num_tokens, num_experts, topk):
gating_output = torch.randn(
(num_tokens, num_experts), dtype=torch.float32, device="cuda"
)
topk_weights = torch.empty((num_tokens, topk), dtype=torch.float32, device="cuda")
topk_indices = torch.empty((num_tokens, topk), dtype=torch.int32, device="cuda")
token_expert_indices = torch.empty(
(num_tokens, topk), dtype=torch.int32, device="cuda"
)
topk_softmax(
topk_weights,
topk_indices,
token_expert_indices,
gating_output,
)
# Native torch implementation
softmax_output = torch.softmax(gating_output, dim=-1)
topk_weights_ref, topk_indices_ref = torch.topk(softmax_output, topk, dim=-1)
# Verify the top-k weights and indices match the torch native ones
assert torch.allclose(
topk_weights_ref, topk_weights, atol=1e-3, rtol=1e-3
), f"Weights mismatch: torch={topk_indices_ref} vs SGLang={topk_weights}"
assert torch.equal(
topk_indices_ref, topk_indices
), f"Indices mismatch: torch={topk_indices_ref}, SGLang={topk_indices}"
print("✅ Native torch and custom kernel implementations match.")
if __name__ == "__main__":
pytest.main([__file__])