src/hotspot/share/gc/z/zDirector.cpp

*** 160,169 ****
--- 160,172 ----
    const size_t used = ZHeap::heap()->used();
    const double time_since_last_gc = ZStatCycle::time_since_last();
    const double time_since_last_gc_threshold = 5 * 60; // 5 minutes
    if (used < used_threshold && time_since_last_gc < time_since_last_gc_threshold) {
      // Don't even consider doing a proactive GC
+     log_debug(gc, director)("Rule: Proactive, UsedUntilEnabled: " SIZE_FORMAT "MB, TimeUntilEnabled: %.3lfs",
+                             (used_threshold - used) / M,
+                             time_since_last_gc_threshold - time_since_last_gc);
      return false;
    }
  
    const double assumed_throughput_drop_during_gc = 0.50; // 50%
    const double acceptable_throughput_drop = 0.01;        // 1%