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sglang/test/registered/kernels/test_fused_topk_deepseek.py

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3.4 KiB
Python

import pytest
import torch
from sglang.srt.layers.moe.topk import biased_grouped_topk_gpu, biased_grouped_topk_impl
from sglang.test.ci.ci_register import register_cuda_ci
register_cuda_ci(est_time=2, suite="nightly-1-gpu", nightly=True)
@pytest.mark.parametrize(
"seq_length",
list(range(1, 10))
+ [16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536],
)
@pytest.mark.parametrize(
"params",
[
(128, 4, 2, 4), # 128 experts configuration
(256, 8, 4, 8), # DeepSeek V3 config - most important to test
(64, 2, 2, 4), # Smaller configuration
],
)
@pytest.mark.parametrize("apply_routed_scaling_factor_on_output", [False, True])
def test_fused_topk_deepseek(seq_length, params, apply_routed_scaling_factor_on_output):
"""
Test the fused_topk_deepseek code path in biased_grouped_topk_gpu.
"""
num_experts, num_expert_group, topk_group, topk = params
dtype = torch.float32
torch.manual_seed(seq_length)
hidden_states = torch.randn(seq_length, 128, dtype=dtype, device="cuda")
gating_output = torch.randn(seq_length, num_experts, dtype=dtype, device="cuda")
correction_bias = torch.randn(num_experts, dtype=dtype, device="cuda")
routed_scaling_factor = 2.5 if apply_routed_scaling_factor_on_output else None
# Fused implementation (uses fused_topk_deepseek when conditions are met)
output, indices = biased_grouped_topk_gpu(
hidden_states,
gating_output,
correction_bias,
topk=topk,
renormalize=True,
num_expert_group=num_expert_group,
topk_group=topk_group,
num_fused_shared_experts=0,
routed_scaling_factor=routed_scaling_factor,
apply_routed_scaling_factor_on_output=apply_routed_scaling_factor_on_output,
)
# Reference implementation (pure PyTorch)
ref_output, ref_indices = biased_grouped_topk_impl(
hidden_states,
gating_output,
correction_bias,
topk=topk,
renormalize=True,
num_expert_group=num_expert_group,
topk_group=topk_group,
num_fused_shared_experts=0,
routed_scaling_factor=routed_scaling_factor,
apply_routed_scaling_factor_on_output=apply_routed_scaling_factor_on_output,
)
# Check 1: Row-wise sums should match (invariant to tie-breaking)
output_sum = output.sum(dim=-1)
ref_output_sum = ref_output.sum(dim=-1)
sum_check = torch.allclose(output_sum, ref_output_sum, rtol=1e-03, atol=1e-04)
# Check 2: Scatter-based comparison with allowance for tie-breaking
res = torch.zeros(seq_length, num_experts, dtype=torch.float32, device="cuda")
ref = torch.zeros(seq_length, num_experts, dtype=torch.float32, device="cuda")
res.scatter_(1, indices.long(), output)
ref.scatter_(1, ref_indices.long(), ref_output)
diff = torch.abs(ref - res)
atol = (
5e-03
if (seq_length >= 4096 and apply_routed_scaling_factor_on_output)
else 1e-03
)
num_large_diffs = (diff > atol).sum().item()
# Allow a small number of differences for tie-breaking situations
max_allowed_diffs = max(16, seq_length // 500)
scatter_check = num_large_diffs <= max_allowed_diffs
assert sum_check and scatter_check, (
f"Output mismatch at seq_length {seq_length}, params {params}, "
f"apply_routed_scaling_factor_on_output {apply_routed_scaling_factor_on_output}"
)
if __name__ == "__main__":
pytest.main([__file__])