fix: change performance log directory to cache path (#13482)

Co-authored-by: Mick <mickjagger19@icloud.com>

.github/workflows/pr-test.yml

@@ -21,9 +21,6 @@ concurrency:
   group: pr-test-${{ github.ref }}
   cancel-in-progress: true
 
-env:
-  SGLANG_IS_IN_CI: true
-
 jobs:
   call-gate:
     uses: ./.github/workflows/pr-gate.yml
@@ -169,11 +166,6 @@ jobs:
           cd sgl-kernel
           pytest tests/
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   sgl-kernel-mla-test:
     needs: [check-changes, sgl-kernel-build-wheels]
     if: needs.check-changes.outputs.sgl_kernel == 'true'
@@ -205,11 +197,6 @@ jobs:
           cd test/srt
           python3 test_mla_deepseek_v3.py
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   sgl-kernel-benchmark-test:
     needs: [check-changes, sgl-kernel-build-wheels]
     if: needs.check-changes.outputs.sgl_kernel == 'true'
@@ -254,11 +241,6 @@ jobs:
 
           echo "All benchmark tests completed!"
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   # =============================================== multimodal_gen ====================================================
   multimodal-gen-test:
     needs: [check-changes]
@@ -278,12 +260,6 @@ jobs:
           cd python
           pytest -s -v --log-cli-level=INFO sglang/multimodal_gen/test/server/test_server_performance.py
 
-     - name: Cleanup logs directory
-       if: always()
-       run: |
-         # Remove logs directory to prevent NFS lock files
-         rm -rf python/sglang/logs || true
-
   # Adding a single CUDA13 smoke test to verify that the kernel builds and runs
   # TODO: Add back this test when it can pass on CI
   # cuda13-kernel-smoke-test:
@@ -387,11 +363,6 @@ jobs:
           cd test/srt
           python3 run_suite.py --suite per-commit-1-gpu --auto-partition-id ${{ matrix.part }} --auto-partition-size 15
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   unit-test-backend-2-gpu:
     needs: [check-changes, unit-test-backend-1-gpu, sgl-kernel-build-wheels]
     if: always() && !failure() && !cancelled() &&
@@ -425,11 +396,6 @@ jobs:
           cd test/srt
           python3 run_suite.py --suite per-commit-2-gpu --auto-partition-id ${{ matrix.part }} --auto-partition-size 2
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   unit-test-backend-4-gpu:
     needs: [check-changes, unit-test-backend-2-gpu, sgl-kernel-build-wheels]
     if: always() && !failure() && !cancelled() &&
@@ -591,11 +557,6 @@ jobs:
           python3 -m unittest test_bench_serving.TestBenchServing.test_lora_online_latency
           python3 -m unittest test_bench_serving.TestBenchServing.test_lora_online_latency_with_concurrent_adapter_updates
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   performance-test-1-gpu-part-2:
     needs: [check-changes, sgl-kernel-build-wheels, stage-a-test-1]
     if: always() && !failure() && !cancelled() &&
@@ -649,11 +610,6 @@ jobs:
           cd test/srt
           python3 -m unittest test_bench_serving.TestBenchServing.test_vlm_online_latency
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   performance-test-1-gpu-part-3:
     needs: [check-changes, sgl-kernel-build-wheels, stage-a-test-1]
     if: always() && !failure() && !cancelled() &&
@@ -765,11 +721,6 @@ jobs:
           cd test/srt
           python3 -m unittest test_bench_serving.TestBenchServing.test_pp_long_context_prefill
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   accuracy-test-1-gpu:
     needs: [check-changes, sgl-kernel-build-wheels, stage-a-test-1]
     if: always() && !failure() && !cancelled() &&
@@ -802,11 +753,6 @@ jobs:
           cd test/srt
           python3 test_eval_accuracy_large.py
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   accuracy-test-2-gpu:
     needs: [check-changes, accuracy-test-1-gpu, sgl-kernel-build-wheels]
     if: always() && !failure() && !cancelled() &&
@@ -839,11 +785,6 @@ jobs:
           cd test/srt
           python3 test_moe_eval_accuracy_large.py
 
-      - name: Cleanup logs directory
-        if: always()
-        run: |
-          rm -rf python/sglang/logs || true
-
   unit-test-deepep-4-gpu:
     needs: [check-changes, unit-test-backend-2-gpu, sgl-kernel-build-wheels]
     if: always() && !failure() && !cancelled() &&
@@ -978,7 +919,7 @@ jobs:
         sgl-kernel-mla-test,
         sgl-kernel-benchmark-test,
 
-        # multimodal-gen-test,
+        multimodal-gen-test,
 
         stage-a-test-1,
         unit-test-backend-1-gpu,

python/sglang/multimodal_gen/runtime/utils/performance_logger.py

@@ -10,13 +10,28 @@ from typing import Any
 
 from dateutil.tz import UTC
 
-LOG_DIR = os.environ.get("SGLANG_PERF_LOG_DIR")
+
-if LOG_DIR:
+def get_diffusion_perf_log_dir() -> str:
-    LOG_DIR = os.path.abspath(LOG_DIR)
+    """
-elif LOG_DIR is None:  # Not set
+    Determines the directory for performance logs, centralizing the logic.
-    project_root = os.path.abspath(os.path.join(os.path.dirname(__file__), "../../../"))
+
-    LOG_DIR = os.path.join(project_root, "logs")
+    Resolution order:
-# if LOG_DIR is "", it will remain "", disabling file logging.
+    1. SGLANG_PERF_LOG_DIR environment variable, if set and not empty.
+    2. Default to ~/.cache/sglang/logs if the environment variable is not set.
+    3. Returns an empty string if SGLANG_PERF_LOG_DIR is set to an empty string,
+       which effectively disables file logging.
+    """
+    log_dir = os.environ.get("SGLANG_PERF_LOG_DIR")
+    if log_dir:
+        return os.path.abspath(log_dir)
+    if log_dir is None:
+        # Not set, use default
+        return os.path.join(os.path.expanduser("~/.cache/sglang"), "logs")
+    # Is set, but is an empty string
+    return ""
+
+
+LOG_DIR = get_diffusion_perf_log_dir()
 
 # Configure a specific logger for performance metrics
 perf_logger = logging.getLogger("performance")

python/sglang/multimodal_gen/test/server/diffusion_server.py

@@ -105,7 +105,7 @@ class ServerManager:
 
     def start(self) -> ServerContext:
         """Start the diffusion server and wait for readiness."""
-        log_dir, perf_log_path = prepare_perf_log(Path(__file__))
+        log_dir, perf_log_path = prepare_perf_log()
 
         safe_model_name = self.model.replace("/", "_")
         stdout_path = (

python/sglang/multimodal_gen/test/test_utils.py

@@ -17,6 +17,9 @@ from PIL import Image
 from sglang.multimodal_gen.configs.sample.base import DataType
 from sglang.multimodal_gen.runtime.utils.common import get_bool_env_var
 from sglang.multimodal_gen.runtime.utils.logging_utils import init_logger
+from sglang.multimodal_gen.runtime.utils.performance_logger import (
+    get_diffusion_perf_log_dir,
+)
 
 logger = init_logger(__name__)
 
@@ -107,12 +110,15 @@ def check_image_size(ut, image, width, height):
     ut.assertEqual(image.size, (width, height))
 
 
-def get_perf_log_dir(start_file: Path) -> Path:
+def get_perf_log_dir() -> Path:
-    """Mirror runtime/utils/performance_logger.py behaviour for locating logs."""
+    """Gets the performance log directory from the centralized sglang utility."""
-    this_file = start_file.resolve()
+    log_dir_str = get_diffusion_perf_log_dir()
-    root_logs = this_file.parents[3] / "logs"
+    if not log_dir_str:
-    fallback = this_file.parents[2] / "logs"
+        raise RuntimeError(
-    return root_logs if root_logs.exists() or not fallback.exists() else fallback
+            "Performance logging is disabled (SGLANG_PERF_LOG_DIR is empty), "
+            "but a test tried to access the log directory."
+        )
+    return Path(log_dir_str)
 
 
 def _ensure_log_path(log_dir: Path) -> Path:
@@ -129,9 +135,9 @@ def clear_perf_log(log_dir: Path) -> Path:
     return log_path
 
 
-def prepare_perf_log(start_file: Path) -> tuple[Path, Path]:
+def prepare_perf_log() -> tuple[Path, Path]:
     """Convenience helper to resolve and clear the perf log in one call."""
-    log_dir = get_perf_log_dir(start_file)
+    log_dir = get_perf_log_dir()
     log_path = clear_perf_log(log_dir)
     return log_dir, log_path