[ROCm][Bugfix][CI] Fix hybrid models and their tests (Mamba/Jamba/Bamba) (#32710)

Signed-off-by: Andreas Karatzas <akaratza@amd.com>
Signed-off-by: Matthew Wong <Matthew.Wong2@amd.com>
Co-authored-by: Matthew Wong <Matthew.Wong2@amd.com>

tests/models/language/generation/test_hybrid.py

@@ -8,6 +8,7 @@ import pytest
 from tests.models.registry import HF_EXAMPLE_MODELS
 from tests.utils import multi_gpu_test
 from vllm.engine.arg_utils import EngineArgs
+from vllm.platforms import current_platform
 from vllm.sampling_params import SamplingParams
 from vllm.v1.cudagraph_dispatcher import CudagraphDispatcher
 
@@ -577,6 +578,10 @@ def test_apc_multiple_prompts_all_cached_outputs(
         model, max_model_len, tensor_parallel_size=tensor_parallel_size
     )
     vllm_runner_kwargs["mamba_ssm_cache_dtype"] = "float32"
+    # Reduce the effects of batch variance on ROCm since batch invariance is not
+    # yet supported. See: https://github.com/vllm-project/vllm/issues/27433
+    if current_platform.is_rocm():
+        vllm_runner_kwargs["max_num_seqs"] = 4
 
     vllm_outputs_no_cache, _ = _get_vLLM_output(
         vllm_runner, vllm_runner_kwargs, generated_prompts, max_tokens, num_logprobs