[Test] Add Unit Test for Batched DeepGEMM (#21559)

Signed-off-by: yewentao256 <zhyanwentao@126.com>

tests/kernels/moe/test_batched_deepgemm.py

+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+import pytest
+import torch
+
+from vllm.model_executor.layers.fused_moe.batched_deep_gemm_moe import (
+    BatchedDeepGemmExperts)
+from vllm.model_executor.layers.fused_moe.fused_batched_moe import (
+    BatchedPrepareAndFinalize, BatchedTritonExperts)
+from vllm.model_executor.layers.fused_moe.modular_kernel import (
+    FusedMoEModularKernel)
+from vllm.utils.deep_gemm import calc_diff, is_deep_gemm_supported
+
+from .test_deepgemm import make_block_quant_fp8_weights
+
+BLOCK_SIZE = [128, 128]
+
+
+@pytest.mark.skipif(not is_deep_gemm_supported(),
+                    reason="Requires deep_gemm kernels")
+@pytest.mark.parametrize("E", [16, 32])  # number of experts
+@pytest.mark.parametrize("T", [256, 512])  # tokens per expert
+@pytest.mark.parametrize("K", [128, 256])  # hidden dim
+@pytest.mark.parametrize("N", [512, 1024])  # intermediate dim per expert
+@pytest.mark.parametrize("topk", [2, 4])
+def test_batched_deepgemm_vs_triton(E: int, T: int, K: int, N: int, topk: int,
+                                    monkeypatch):
+    """Compare BatchedDeepGemmExperts to BatchedTritonExperts."""
+
+    monkeypatch.setenv("VLLM_USE_DEEP_GEMM", "1")
+
+    device = "cuda"
+    w1, w2, w1_s, w2_s = make_block_quant_fp8_weights(E, N, K, BLOCK_SIZE)
+
+    M = E * T  # total tokens
+    a = torch.randn(M, K, device=device, dtype=torch.bfloat16) / 10.0
+    fp8_info = torch.finfo(torch.float8_e4m3fn)
+    a.clamp_(fp8_info.min, fp8_info.max)
+
+    # random router outputs → top-k indices / weights
+    router_logits = torch.randn(M, E, device=device, dtype=torch.float32)
+    topk_weights, topk_ids = torch.topk(router_logits, k=topk, dim=-1)
+    topk_weights = torch.nn.functional.softmax(topk_weights, dim=-1)
+
+    # token number for each expert
+    cnt = torch.bincount(topk_ids.flatten(), minlength=E)
+    max_cnt = int(cnt.max().item())
+    # next power of 2 for max token number
+    max_num_tokens = 1 << (max_cnt - 1).bit_length()
+
+    prep_finalize = BatchedPrepareAndFinalize(
+        max_num_tokens=max_num_tokens,
+        num_local_experts=E,
+        num_dispatchers=1,
+        rank=0,
+    )
+
+    # triton (reference)
+    triton_experts = BatchedTritonExperts(
+        max_num_tokens=max_num_tokens,
+        num_dispatchers=1,
+        use_fp8_w8a8=True,
+        per_act_token_quant=False,
+        block_shape=BLOCK_SIZE,
+    )
+    mk_triton = FusedMoEModularKernel(prep_finalize, triton_experts)
+
+    out_triton = mk_triton(
+        hidden_states=a,
+        w1=w1,
+        w2=w2,
+        topk_weights=topk_weights,
+        topk_ids=topk_ids,
+        inplace=False,
+        w1_scale=w1_s,
+        w2_scale=w2_s,
+        global_num_experts=E,
+    )
+
+    # deepgemm
+    deepgemm_experts = BatchedDeepGemmExperts(
+        max_num_tokens=max_num_tokens,
+        num_dispatchers=1,
+        block_shape=BLOCK_SIZE,
+        per_act_token_quant=False,
+    )
+    mk_deepgemm = FusedMoEModularKernel(prep_finalize, deepgemm_experts)
+
+    out_deepgemm = mk_deepgemm(
+        hidden_states=a,
+        w1=w1,
+        w2=w2,
+        topk_weights=topk_weights,
+        topk_ids=topk_ids,
+        inplace=False,
+        w1_scale=w1_s,
+        w2_scale=w2_s,
+        global_num_experts=E,
+    )
+
+    diff = calc_diff(out_deepgemm, out_triton)
+    assert diff < 1e-3, f"Output diff too large: {diff}"

tests/kernels/moe/test_deepgemm.py

@@ -20,11 +20,6 @@ from vllm.utils.deep_gemm import (calc_diff, is_deep_gemm_supported,
 
 BLOCK_SIZE = [128, 128]
 
-requires_deep_gemm = pytest.mark.skipif(
-    not is_deep_gemm_supported(),
-    reason="Requires deep_gemm kernels",
-)
-
 
 def make_block_quant_fp8_weights(
     e: int,
@@ -152,7 +147,8 @@ NUM_EXPERTS = [32]
 @pytest.mark.parametrize("mnk", MNKs)
 @pytest.mark.parametrize("topk", TOPKS)
 @pytest.mark.parametrize("num_experts", NUM_EXPERTS)
-@requires_deep_gemm
+@pytest.mark.skipif(not is_deep_gemm_supported(),
+                    reason="Requires deep_gemm kernels")
 def test_deepgemm_vs_triton(mnk, topk, num_experts, monkeypatch):
 
     with monkeypatch.context() as m:

vllm/utils/deep_gemm.py

@@ -23,10 +23,10 @@ def is_deep_gemm_supported() -> bool:
     """Return ``True`` if DeepGEMM is supported on the current platform.
     Currently, only Hopper and Blackwell GPUs are supported.
     """
-    supported_arch = current_platform.is_cuda() and (
+    is_supported_arch = current_platform.is_cuda() and (
         current_platform.is_device_capability(90)
         or current_platform.is_device_capability(100))
-    return has_deep_gemm() and supported_arch
+    return has_deep_gemm() and is_supported_arch
 
 
 @functools.cache