[TRTLLM-4721][test] Add qa test for llm-api

tensorrt_llm/llmapi/llm.py

@@ -122,15 +122,21 @@ def __init__(self,
         self._executor_cls = kwargs.pop("executor_cls", GenerationExecutor)
         self._llm_id = None
 
+        log_level = logger.level
+        logger.set_level("info")  # force display the backend
+
         try:
             backend = kwargs.get('backend', None)
-            if backend == 'pytorch':
+            if backend == "pytorch":
+                logger.info("Using LLM with PyTorch backend")
                 llm_args_cls = TorchLlmArgs
             elif backend == '_autodeploy':
+                logger.info("Using LLM with AutoDeploy backend")
                 from .._torch.auto_deploy.llm_args import \
                     LlmArgs as AutoDeployLlmArgs
                 llm_args_cls = AutoDeployLlmArgs
             else:
+                logger.info("Using LLM with TensorRT backend")
                 llm_args_cls = TrtLlmArgs
 
             # check the kwargs and raise ValueError directly
@@ -160,6 +166,9 @@ def __init__(self,
                 f"Failed to parse the arguments for the LLM constructor: {e}")
             raise e
 
+        finally:
+            logger.set_level(log_level)  # restore the log level
+
         print_colored_debug(f"LLM.args.mpi_session: {self.args.mpi_session}\n",
                             "yellow")
         self.mpi_session = self.args.mpi_session

tests/integration/defs/llmapi/_run_llmapi_llm.py

@@ -1,25 +1,32 @@
 #!/usr/bin/env python3
 import os
+from typing import Optional
 
 import click
 
-from tensorrt_llm._tensorrt_engine import LLM
-from tensorrt_llm.llmapi import BuildConfig, SamplingParams
+from tensorrt_llm._tensorrt_engine import LLM as TrtLLM
+from tensorrt_llm.llmapi import LLM, BuildConfig, SamplingParams
 
 
 @click.command()
 @click.option("--model_dir", type=str, required=True)
 @click.option("--tp_size", type=int, default=1)
 @click.option("--engine_dir", type=str, default=None)
-def main(model_dir: str, tp_size: int, engine_dir: str):
+@click.option("--backend", type=str, default=None)
+def main(model_dir: str, tp_size: int, engine_dir: str, backend: Optional[str]):
     build_config = BuildConfig()
     build_config.max_batch_size = 8
     build_config.max_input_len = 256
     build_config.max_seq_len = 512
 
-    llm = LLM(model_dir,
-              tensor_parallel_size=tp_size,
-              build_config=build_config)
+    backend = backend or "tensorrt"
+    assert backend in ["pytorch", "tensorrt"]
+
+    llm_cls = TrtLLM if backend == "tensorrt" else LLM
+
+    kwargs = {} if backend == "pytorch" else {"build_config": build_config}
+
+    llm = llm_cls(model_dir, tensor_parallel_size=tp_size, **kwargs)
 
     if engine_dir is not None and os.path.abspath(
             engine_dir) != os.path.abspath(model_dir):

tests/integration/defs/llmapi/test_llm_api_qa.py

@@ -0,0 +1,70 @@
+# Confirm that the default backend is changed
+import os
+
+from defs.common import venv_check_output
+
+from ..conftest import llm_models_root
+
+model_path = llm_models_root() + "/llama-models-v3/llama-v3-8b-instruct-hf"
+
+
+class TestLlmDefaultBackend:
+    """
+    Check that the default backend is PyTorch for v1.0 breaking change
+    """
+
+    def test_llm_args_type_default(self, llm_root, llm_venv):
+        # Keep the complete example code here
+        from tensorrt_llm.llmapi import LLM, KvCacheConfig, TorchLlmArgs
+
+        kv_cache_config = KvCacheConfig(free_gpu_memory_fraction=0.4)
+        llm = LLM(model=model_path, kv_cache_config=kv_cache_config)
+
+        # The default backend should be PyTorch
+        assert llm.args.backend == "pytorch"
+        assert isinstance(llm.args, TorchLlmArgs)
+
+        for output in llm.generate(["Hello, world!"]):
+            print(output)
+
+    def test_llm_args_type_tensorrt(self, llm_root, llm_venv):
+        # Keep the complete example code here
+        from tensorrt_llm._tensorrt_engine import LLM
+        from tensorrt_llm.llmapi import KvCacheConfig, TrtLlmArgs
+
+        kv_cache_config = KvCacheConfig(free_gpu_memory_fraction=0.4)
+
+        llm = LLM(model=model_path, kv_cache_config=kv_cache_config)
+
+        # If the backend is TensorRT, the args should be TrtLlmArgs
+        assert llm.args.backend in ("tensorrt", None)
+        assert isinstance(llm.args, TrtLlmArgs)
+
+        for output in llm.generate(["Hello, world!"]):
+            print(output)
+
+    def test_llm_args_logging(self, llm_root, llm_venv):
+        # It should print the backend in the log
+        script_path = os.path.join(os.path.dirname(__file__),
+                                   "_run_llmapi_llm.py")
+        print(f"script_path: {script_path}")
+
+        # Test with pytorch backend
+        pytorch_cmd = [
+            script_path, "--model_dir", model_path, "--backend", "pytorch"
+        ]
+
+        pytorch_output = venv_check_output(llm_venv, pytorch_cmd)
+
+        # Check that pytorch backend keyword appears in logs
+        assert "Using LLM with PyTorch backend" in pytorch_output, f"Expected 'pytorch' in logs, got: {pytorch_output}"
+
+        # Test with tensorrt backend
+        tensorrt_cmd = [
+            script_path, "--model_dir", model_path, "--backend", "tensorrt"
+        ]
+
+        tensorrt_output = venv_check_output(llm_venv, tensorrt_cmd)
+
+        # Check that tensorrt backend keyword appears in logs
+        assert "Using LLM with TensorRT backend" in tensorrt_output, f"Expected 'tensorrt' in logs, got: {tensorrt_output}"

tests/integration/test_lists/qa/llm_function_full.txt

@@ -677,3 +677,9 @@ disaggregated/test_workers.py::test_workers_kv_cache_aware_router_eviction[TinyL
 # These tests will impact triton. They should be at the end of all tests (https://nvbugs/4904271)
 # examples/test_openai.py::test_llm_openai_triton_1gpu
 # examples/test_openai.py::test_llm_openai_triton_plugingen_1gpu
+
+# llm-api promote pytorch to default
+llmapi/test_llm_api_qa.py::TestLlmDefaultBackend::test_llm_args_logging
+llmapi/test_llm_api_qa.py::TestLlmDefaultBackend::test_llm_args_type_tensorrt
+llmapi/test_llm_api_qa.py::TestLlmDefaultBackend::test_llm_args_type_default
+llmapi/test_llm_api_qa.py::TestLlmDefaultBackend::test_llm_args_logging