--- old/src/hotspot/share/gc/g1/g1Analytics.cpp	2020-06-15 11:18:29.724508773 +0200
+++ new/src/hotspot/share/gc/g1/g1Analytics.cpp	2020-06-15 11:18:29.632507603 +0200
@@ -224,7 +224,11 @@
 }
 
 double G1Analytics::predict_alloc_rate_ms() const {
-  return predict_zero_bounded(_alloc_rate_ms_seq);
+  if (enough_samples_available(_alloc_rate_ms_seq)) {
+    return predict_zero_bounded(_alloc_rate_ms_seq);
+  } else {
+    return 0.0;
+  }
 }
 
 double G1Analytics::predict_concurrent_refine_rate_ms() const {