src/share/vm/gc_implementation/shenandoah/shenandoahPacer.cpp

rev 11463 : Backport Traversal GC

@@ -125,10 +125,37 @@
                      byte_size_in_proper_unit(non_taxable), proper_unit_for_byte_size(non_taxable),
                      tax);
 }
 
 /*
+ * Traversal walks the entire heap once, and therefore we have to make assumptions about its
+ * liveness, like concurrent mark does.
+ */
+
+void ShenandoahPacer::setup_for_traversal() {
+  assert(ShenandoahPacing, "Only be here when pacing is enabled");
+
+  size_t live = update_and_get_progress_history();
+  size_t free = _heap->free_set()->available();
+
+  size_t non_taxable = free * ShenandoahPacingCycleSlack / 100;
+  size_t taxable = free - non_taxable;
+
+  double tax = 1.0 * live / taxable; // base tax for available free space
+  tax *= ShenandoahPacingSurcharge;  // additional surcharge to help unclutter heap
+
+  restart_with(non_taxable, tax);
+
+  log_info(gc, ergo)("Pacer for Traversal. Expected Live: " SIZE_FORMAT "%s, Free: " SIZE_FORMAT "%s, "
+                     "Non-Taxable: " SIZE_FORMAT "%s, Alloc Tax Rate: %.1fx",
+                     byte_size_in_proper_unit(live),        proper_unit_for_byte_size(live),
+                     byte_size_in_proper_unit(free),        proper_unit_for_byte_size(free),
+                     byte_size_in_proper_unit(non_taxable), proper_unit_for_byte_size(non_taxable),
+                     tax);
+}
+
+/*
  * In idle phase, we have to pace the application to let control thread react with GC start.
  *
  * Here, we have rendezvous with concurrent thread that adds up the budget as it acknowledges
  * it had seen recent allocations. It will naturally pace the allocations if control thread is
  * not catching up. To bootstrap this feedback cycle, we need to start with some initial budget