Fix LoRA buffer contamination during adapter eviction (#8103)

test/srt/models/lora/test_lora_eviction.py

@@ -0,0 +1,111 @@
+# Copyright 2023-2024 SGLang Team
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+import multiprocessing as mp
+import unittest
+from typing import Dict, List, Tuple
+
+import torch
+
+from sglang.test.runners import SRTRunner
+from sglang.test.test_utils import CustomTestCase
+
+PROMPTS = [
+    "AI is a field of computer science focused on",
+    """
+    ### Instruction:
+    Compose a SQL query that uses the following table: users, and returns the user_id and name of all users whose name that does not have a duplicate in the table.
+    ### Response:
+    SELECT user_id, name FROM users WHERE name LIKE 'A%';
+    """,
+]
+
+ADAPTERS = [
+    "faridlazuarda/valadapt-llama-3.1-8B-it-chinese",  # target_modules = q, v
+    "philschmid/code-llama-3-1-8b-text-to-sql-lora",  # target_modules = q, k, v, o, gate, up, down
+]
+
+BASE_MODEL = "meta-llama/Meta-Llama-3.1-8B-Instruct"
+
+
+class TestLoRAEviction(CustomTestCase):
+    def test_lora_eviction_with_different_target_modules(self):
+        """
+        Test LoRA eviction with different target modules.
+
+        This test runs inference against two LoRA adapters in different orders to force eviction behavior, and ensures
+        that the outputs of the same (adapter, prompt) pair are consistent across runs.
+        """
+        output_history = {}
+        self._run_test(ADAPTERS, output_history, reverse=False)
+        self._run_test(ADAPTERS, output_history, reverse=True)
+
+    def _run_test(
+        self,
+        lora_paths: List[str],
+        output_history: Dict[Tuple[str, str], str],
+        reverse: bool,
+        repeat: int = 2,
+    ):
+        max_new_tokens = 256
+        backend = "triton"
+        torch_dtype = torch.float16
+        base_path = BASE_MODEL
+        assert len(lora_paths) >= 2
+
+        # Initialize runners
+        with SRTRunner(
+            base_path,
+            torch_dtype=torch_dtype,
+            model_type="generation",
+            lora_paths=lora_paths,
+            max_loras_per_batch=1,
+            lora_backend=backend,
+            disable_radix_cache=True,
+        ) as srt_runner:
+            adapter_sequence = lora_paths if not reverse else lora_paths[::-1]
+
+            for i in range(repeat):
+                for j, adapter in enumerate(adapter_sequence):
+                    print(
+                        f"\n========== Testing LoRA eviction with adapter '{adapter}' (#{j+1}/{len(adapter_sequence)}), reversed: {reverse}, repeat: {i+1}/{repeat} ---"
+                    )
+                    for prompt in PROMPTS:
+                        print("\nprompt:\n", prompt)
+                        srt_outputs = srt_runner.forward(
+                            [prompt],
+                            max_new_tokens=max_new_tokens,
+                            lora_paths=[adapter],
+                        )
+                        output = srt_outputs.output_strs[0].strip()
+                        print("\noutput:\n", output)
+
+                        prev_output = output_history.get((adapter, prompt))
+                        if prev_output is not None:
+                            self.assertEqual(
+                                prev_output,
+                                output,
+                                f"Output mismatch for adapter {adapter} and prompt '{prompt}' on repeat {j + 1}, previous: '{prev_output}', current: '{output}'.",
+                            )
+                        else:
+                            output_history[(adapter, prompt)] = output
+
+
+if __name__ == "__main__":
+    try:
+        mp.set_start_method("spawn")
+    except RuntimeError:
+        pass
+
+    unittest.main(warnings="ignore")

test/srt/run_suite.py

@@ -14,6 +14,7 @@ class TestFile:
 suites = {
     "per-commit": [
         TestFile("models/lora/test_lora.py", 200),
+        TestFile("models/lora/test_lora_eviction.py", 120),
         TestFile("models/lora/test_lora_backend.py", 99),
         TestFile("models/lora/test_multi_lora_backend.py", 60),
         TestFile("models/lora/test_lora_cuda_graph.py", 250),