[core] gemma2 full context length support (#10584)

Signed-off-by: youkaichao <youkaichao@gmail.com>

tests/basic_correctness/test_basic_correctness.py

@@ -14,11 +14,12 @@ from vllm import LLM
 from vllm.platforms import current_platform
 from vllm.worker.model_runner import ModelInputForGPUWithSamplingMetadata
 
+from ..conftest import VllmRunner
 from ..models.utils import check_outputs_equal
 from ..utils import multi_gpu_test
 
 MODELS = [
-    "facebook/opt-125m",
+    "google/gemma-2-2b-it",
     "meta-llama/Llama-3.2-1B",
 ]
 
@@ -42,8 +43,6 @@ def test_vllm_gc_ed():
 @pytest.mark.parametrize("enforce_eager", [False, True])
 def test_models(
     hf_runner,
-    vllm_runner,
-    example_prompts,
     model: str,
     backend: str,
     dtype: str,
@@ -54,15 +53,27 @@ def test_models(
     if backend == "FLASHINFER" and current_platform.is_rocm():
         pytest.skip("Flashinfer does not support ROCm/HIP.")
 
+    if backend == "XFORMERS" and model == "google/gemma-2-2b-it":
+        pytest.skip(
+            "XFORMERS does not support gemma2 with full context length.")
+
     os.environ["VLLM_ATTENTION_BACKEND"] = backend
 
+    # 5042 tokens for gemma2
+    # gemma2 has alternating sliding window size of 4096
+    # we need a prompt with more than 4096 tokens to test the sliding window
+    prompt = "The following numbers of the sequence " + ", ".join(
+        str(i) for i in range(1024)) + " are:"
+    example_prompts = [prompt]
+
     with hf_runner(model, dtype=dtype) as hf_model:
         hf_outputs = hf_model.generate_greedy(example_prompts, max_tokens)
 
-    with vllm_runner(model,
-                     dtype=dtype,
-                     enforce_eager=enforce_eager,
-                     gpu_memory_utilization=0.7) as vllm_model:
+    with VllmRunner(model,
+                    max_model_len=8192,
+                    dtype=dtype,
+                    enforce_eager=enforce_eager,
+                    gpu_memory_utilization=0.7) as vllm_model:
         vllm_outputs = vllm_model.generate_greedy(example_prompts, max_tokens)
 
     check_outputs_equal(