[Bugfix] Guard mixed-dtype allreduce RMSNorm quant fusions (#48330)

Signed-off-by: hcenteno <hugo.centeno@estudiantat.upc.edu>
(cherry picked from commit 5f8e73cb8b)

tests/compile/passes/distributed/test_fusion_all_reduce.py

@@ -222,6 +222,25 @@ class TestAllReduceRMSNormStaticQuantFP8Model(torch.nn.Module):
         ]
 
 
+class TestAllReduceGemmaRMSNormStaticQuantFP8Model(
+    TestAllReduceRMSNormStaticQuantFP8Model
+):
+    def __init__(
+        self,
+        hidden_size=16,
+        token_num=16,
+        eps=1e-6,
+        dtype: torch.dtype = torch.float16,
+    ):
+        super().__init__(hidden_size, token_num, eps, dtype)
+        self.norm = [GemmaRMSNorm(hidden_size, eps) for _ in range(4)]
+        for norm in self.norm:
+            norm.weight.requires_grad_(False)
+
+    def ops_in_model_before(self):
+        return [torch.ops.vllm.all_reduce.default]
+
+
 class TestAiterAllReduceRMSNormGroupQuantFP8Model(torch.nn.Module):
     """Exercises the new ROCm AITER AR+RMS+per-group-FP8-quant patterns.
 
@@ -416,6 +435,15 @@ class TestAllReduceFusedAddRMSNormStaticQuantFP4Model(torch.nn.Module):
                 reason="Not supported on ROCm platform",
             ),
         ),
+        pytest.param(
+            TestAllReduceGemmaRMSNormStaticQuantFP8Model,
+            True,
+            False,
+            marks=pytest.mark.skipif(
+                current_platform.is_rocm(),
+                reason="Not supported on ROCm platform",
+            ),
+        ),
         pytest.param(
             TestAllReduceRMSNormStaticQuantFP8Model,
             False,
@@ -606,7 +634,10 @@ def all_reduce_fusion_pass_on_test_model(
         )
         backend.check_before_ops(model.ops_in_model_before(), fully_replaced=False)
         backend.check_after_ops(model.ops_in_model_after())
-        if test_model_cls is TestAllReduceGemmaRMSNormModel:
+        if test_model_cls in (
+            TestAllReduceGemmaRMSNormModel,
+            TestAllReduceGemmaRMSNormStaticQuantFP8Model,
+        ):
             fused_op = torch.ops.vllm.flashinfer_trtllm_fused_allreduce_norm.default
             fused_nodes = list(find_op_nodes(fused_op, backend.graph_post_pass))
             assert fused_nodes

vllm/compilation/passes/fusion/allreduce_rms_fusion.py

@@ -752,7 +752,12 @@ class AllReduceFusedAddRMSNormStaticQuantFP8Pattern(BasePattern):
             return allreduce[4], allreduce[2]
 
         pm.register_replacement(
-            pattern, replacement, self.get_inputs(), pm.fwd_only, pm_pass
+            pattern,
+            replacement,
+            self.get_inputs(),
+            pm.fwd_only,
+            pm_pass,
+            extra_check=_norm_input_weight_dtype_match,
         )
 
 
@@ -941,7 +946,12 @@ class AllReduceFusedAddRMSNormStaticQuantNVFP4Pattern(BasePattern):
             return allreduce[4], allreduce[2], allreduce[5]
 
         pm.register_replacement(
-            pattern, replacement, self.get_inputs(), pm.fwd_only, pm_pass
+            pattern,
+            replacement,
+            self.get_inputs(),
+            pm.fwd_only,
+            pm_pass,
+            extra_check=_norm_input_weight_dtype_match,
         )
 
 

vllm/multimodal/video.py

@@ -15,7 +15,7 @@ import torch
 
 from vllm import envs
 from vllm.logger import init_logger
-from vllm.utils.import_utils import PlaceholderModule
+from vllm.utils.import_utils import PlaceholderModule, check_torchcodec_available
 from vllm.utils.mem_constants import MiB_bytes
 from vllm.utils.registry import ExtensionManager
 
@@ -33,7 +33,7 @@ except ImportError:
 
 try:
     from torchcodec.decoders import VideoDecoder
-except ImportError:
+except (ImportError, RuntimeError):
     VideoDecoder = PlaceholderModule("torchcodec").placeholder_attr(  # type: ignore[assignment]
         "decoders.VideoDecoder"
     )
@@ -956,6 +956,7 @@ class VideoBackend(
             assert not frame_recovery, (
                 "frame_recovery is only available for `opencv` backend"
             )
+            check_torchcodec_available()
             decoder = cls.make_torchcodec_decoder(
                 data,
                 num_ffmpeg_threads=num_ffmpeg_threads,

vllm/utils/import_utils.py

@@ -552,3 +552,21 @@ def has_cutedsl() -> bool:
 def has_humming() -> bool:
     """Whether the optional `humming` package is available."""
     return _has_module("humming")
+
+
+def check_torchcodec_available():
+    """Whether the optional `torchcodec` package is available."""
+    try:
+        import torchcodec  # noqa: F401
+    except RuntimeError as e:
+        # torchcodec will raise RuntimeError during import instead
+        # of ImportError when system ffmpeg unavailable, with a
+        # message that can leak sensitive system information.
+        # Trim it down to avoid it.
+        marker = (
+            "The following exceptions were raised as we tried to load libtorchcodec:"
+        )
+        message = str(e)
+        if marker in message:
+            raise RuntimeError(message.split(marker, 1)[0].rstrip()) from None
+        raise e