Log a warning when remote-deployments-poll-interval gets clamped

pkg/reconciler/common/poll_interval_flag.go

@@ -40,3 +40,9 @@ func RemoteDeploymentsPollIntervalValue() time.Duration {
 	}
 	return remoteDeploymentsPollIntervalFlag
 }
+
+// RemoteDeploymentsPollIntervalWasClamped reports whether the configured
+// remote-deployments-poll-interval value was below 1s and fell back to the default.
+func RemoteDeploymentsPollIntervalWasClamped() bool {
+	return remoteDeploymentsPollIntervalFlag < time.Second
+}

pkg/reconciler/common/poll_interval_flag_test.go

@@ -45,3 +45,29 @@ func TestRemoteDeploymentsPollIntervalValue(t *testing.T) {
 		})
 	}
 }
+
+func TestRemoteDeploymentsPollIntervalWasClamped(t *testing.T) {
+	cases := []struct {
+		name string
+		flag time.Duration
+		want bool
+	}{
+		{"default", defaultRemoteDeploymentsPollInterval, false},
+		{"valid override", 30 * time.Second, false},
+		{"exactly one second", time.Second, false},
+		{"below threshold", 500 * time.Millisecond, true},
+		{"zero", 0, true},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			prev := remoteDeploymentsPollIntervalFlag
+			remoteDeploymentsPollIntervalFlag = tc.flag
+			t.Cleanup(func() { remoteDeploymentsPollIntervalFlag = prev })
+
+			if got := RemoteDeploymentsPollIntervalWasClamped(); got != tc.want {
+				t.Errorf("RemoteDeploymentsPollIntervalWasClamped() = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}

pkg/reconciler/knativeeventing/controller.go

@@ -62,6 +62,9 @@ func NewExtendedController(generator common.ExtensionGenerator) injection.Contro
 		kubeClient := kubeclient.Get(ctx)
 		logger := logging.FromContext(ctx)
 		logger.Infof("Remote deployments poll interval: %s", common.RemoteDeploymentsPollIntervalValue())
+		if common.RemoteDeploymentsPollIntervalWasClamped() {
+			logger.Warnf("remote-deployments-poll-interval below 1s, falling back to default")
+		}
 
 		restConfig := injection.GetConfig(ctx)
 		mfclient, err := mfc.NewClient(restConfig)

pkg/reconciler/knativeserving/controller.go

@@ -62,6 +62,9 @@ func NewExtendedController(generator common.ExtensionGenerator) injection.Contro
 		kubeClient := kubeclient.Get(ctx)
 		logger := logging.FromContext(ctx)
 		logger.Infof("Remote deployments poll interval: %s", common.RemoteDeploymentsPollIntervalValue())
+		if common.RemoteDeploymentsPollIntervalWasClamped() {
+			logger.Warnf("remote-deployments-poll-interval below 1s, falling back to default")
+		}
 
 		restConfig := injection.GetConfig(ctx)
 		mfclient, err := mfc.NewClient(restConfig)