Enable GIL monitoring when gilknocker installed (#7730)

distributed/distributed.yaml

@@ -312,7 +312,7 @@ distributed:
       disk: true  # Monitor host-wide disk I/O
       host-cpu: false  # Monitor host-wide CPU usage, with very granular breakdown
       gil: 
-        enabled: false  # Monitor GIL contention
+        enabled: true  # Monitor GIL contention
         interval: "1ms"  # Frequency to poll GIL
     event-loop: tornado
   rmm:

distributed/http/scheduler/tests/test_scheduler_http.py

@@ -107,6 +107,7 @@ async def test_prometheus(c, s, a, b):
     expected_metrics = {
         "dask_scheduler_clients",
         "dask_scheduler_desired_workers",
+        "dask_scheduler_gil_contention",
         "dask_scheduler_workers",
         "dask_scheduler_last_time",
         "dask_scheduler_tasks",

distributed/http/worker/tests/test_worker_http.py

@@ -32,6 +32,7 @@ async def test_prometheus(c, s, a):
     )
     expected_metrics = {
         "dask_worker_concurrent_fetch_requests",
+        "dask_worker_gil_contention_total",
         "dask_worker_latency_seconds",
         "dask_worker_memory_bytes",
         "dask_worker_spill_bytes_total",

distributed/system_monitor.py

@@ -233,7 +233,4 @@ def range_query(self, start: int) -> dict[str, list]:
 
     def close(self) -> None:
         if self.monitor_gil_contention:
-            try:
-                self._gilknocker.stop()
-            except ValueError:  # Wasn't started or already stopped
-                pass
+            self._gilknocker.stop()

distributed/tests/test_system_monitor.py

@@ -101,20 +101,22 @@ def test_host_cpu():
 def test_gil_contention():
     pytest.importorskip("gilknocker")
 
+    # Default enabled if gilknocker installed
     sm = SystemMonitor()
     a = sm.update()
-    assert "gil_contention" not in a
-
-    sm = SystemMonitor(monitor_gil_contention=True)
-    a = sm.update()
     assert "gil_contention" in a
 
-    with dask.config.set({"distributed.admin.system-monitor.gil.enabled": True}):
-        sm = SystemMonitor()
-        a = sm.update()
-        assert "gil_contention" in a
-
     assert sm._gilknocker.is_running
     sm.close()
     sm.close()  # Idempotent
     assert not sm._gilknocker.is_running
+
+    sm = SystemMonitor(monitor_gil_contention=False)
+    a = sm.update()
+    assert "gil_contention" not in a
+
+    assert dask.config.get("distributed.admin.system-monitor.gil.enabled")
+    with dask.config.set({"distributed.admin.system-monitor.gil.enabled": False}):
+        sm = SystemMonitor()
+        a = sm.update()
+        assert "gil_contention" not in a