[Metrics] Fix fwd_occupancy reading NaN on every decode log line; probe-free base-a (#27836)

test/registered/core/test_basic_sanity.py

@@ -34,8 +34,9 @@ class TestBasicSanity(
 ):
     served_model_name = DEFAULT_MODEL_NAME_FOR_TEST
     # 5090 + Llama-3.1-8B single-batch decode with overlap scheduler +
-    # cuda graph measured ~99 median in CI; keep ~2pp headroom.
-    fwd_occupancy_threshold = 97.0
+    # cuda graph measured ~99 median in CI; async-assert probes are off in
+    # base-a, so the threshold can sit right under the measured median.
+    fwd_occupancy_threshold = 99.0
 
     @classmethod
     def setUpClass(cls):

test/registered/core/test_basic_sanity_eagle3.py

@@ -33,10 +33,11 @@ class TestBasicSanityEagle3(
     CustomTestCase,
 ):
     served_model_name = DEFAULT_TARGET_MODEL_EAGLE3
-    # CUDA 5090 + Llama-3.1-8B measured ~99 median in CI. AMD EAGLE3
-    # currently sustains lower single-batch occupancy and needs a longer
-    # measurement window to avoid too few non-NaN samples.
-    fwd_occupancy_threshold = 80.0 if is_in_amd_ci() else 97.0
+    # CUDA 5090 + Llama-3.1-8B measured ~99 median in CI with async-assert
+    # probes off in base-a. AMD EAGLE3 currently sustains lower single-batch
+    # occupancy and needs a longer measurement window to avoid too few
+    # non-NaN samples.
+    fwd_occupancy_threshold = 80.0 if is_in_amd_ci() else 98.0
     fwd_occupancy_max_new_tokens = 4096 if is_in_amd_ci() else 2048
     fwd_occupancy_acc_length_threshold: float = 1.6