[Feature] Add env var `VLLM_MOE_USE_DEEP_GEMM` (#28422)

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

vllm/envs.py

@@ -147,6 +147,7 @@ if TYPE_CHECKING:
     VLLM_TPU_MOST_MODEL_LEN: int | None = None
     VLLM_TPU_USING_PATHWAYS: bool = False
     VLLM_USE_DEEP_GEMM: bool = True
+    VLLM_MOE_USE_DEEP_GEMM: bool = True
     VLLM_USE_DEEP_GEMM_E8M0: bool = True
     VLLM_DEEP_GEMM_WARMUP: Literal[
         "skip",
@@ -1116,6 +1117,10 @@ environment_variables: dict[str, Callable[[], Any]] = {
     ),
     # Allow use of DeepGemm kernels for fused moe ops.
     "VLLM_USE_DEEP_GEMM": lambda: bool(int(os.getenv("VLLM_USE_DEEP_GEMM", "1"))),
+    # Allow use of DeepGemm specifically for MoE fused ops (overrides only MoE).
+    "VLLM_MOE_USE_DEEP_GEMM": lambda: bool(
+        int(os.getenv("VLLM_MOE_USE_DEEP_GEMM", "1"))
+    ),
     # Whether to use E8M0 scaling when DeepGEMM is used on Blackwell GPUs.
     "VLLM_USE_DEEP_GEMM_E8M0": lambda: bool(
         int(os.getenv("VLLM_USE_DEEP_GEMM_E8M0", "1"))
@@ -1569,6 +1574,7 @@ def compute_hash() -> str:
         "VLLM_USE_FLASHINFER_SAMPLER",
         "VLLM_DISABLED_KERNELS",
         "VLLM_USE_DEEP_GEMM",
+        "VLLM_MOE_USE_DEEP_GEMM",
         "VLLM_USE_DEEP_GEMM_E8M0",
         "VLLM_USE_FUSED_MOE_GROUPED_TOPK",
         "VLLM_USE_FLASHINFER_MOE_FP16",

vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors_moe.py

@@ -966,10 +966,18 @@ class CompressedTensorsW8A8Fp8MoEMethod(CompressedTensorsMoEMethod):
                 max_num_tokens=max_num_tokens_per_rank,
                 num_dispatchers=prepare_finalize.num_dispatchers(),
                 quant_config=self.moe_quant_config,
+                allow_deep_gemm=(
+                    envs.VLLM_USE_DEEP_GEMM and envs.VLLM_MOE_USE_DEEP_GEMM
+                ),
             )
         else:
             logger.debug("TritonOrDeepGemmExperts(%s)", self.__class__.__name__)
-            return TritonOrDeepGemmExperts(self.moe_quant_config, allow_deep_gemm=True)
+            return TritonOrDeepGemmExperts(
+                self.moe_quant_config,
+                allow_deep_gemm=(
+                    envs.VLLM_USE_DEEP_GEMM and envs.VLLM_MOE_USE_DEEP_GEMM
+                ),
+            )
 
     def get_fused_moe_quant_config(
         self, layer: torch.nn.Module

vllm/model_executor/layers/quantization/fp8.py

@@ -158,7 +158,7 @@ def get_fp8_moe_backend(block_quant: bool) -> Fp8MoeBackend:
         return Fp8MoeBackend.MARLIN
 
     # deepGEMM on supported platforms with block-quantized weights
-    if envs.VLLM_USE_DEEP_GEMM and block_quant:
+    if envs.VLLM_USE_DEEP_GEMM and envs.VLLM_MOE_USE_DEEP_GEMM and block_quant:
         if not has_deep_gemm():
             logger.warning_once("DeepGEMM backend requested but not available.")
         elif is_deep_gemm_supported():

vllm/model_executor/warmup/deep_gemm_warmup.py

@@ -148,6 +148,9 @@ def _fp8_linear_may_use_deep_gemm(module: torch.nn.Module) -> bool:
 
 
 def _fused_moe_grouped_gemm_may_use_deep_gemm(module: torch.nn.Module) -> bool:
+    if not (envs.VLLM_USE_DEEP_GEMM and envs.VLLM_MOE_USE_DEEP_GEMM):
+        return False
+
     if not isinstance(module, FusedMoE):
         return False