--- old/src/hotspot/share/gc/shared/genCollectedHeap.cpp	2018-12-11 20:59:07.344826251 +0100
+++ new/src/hotspot/share/gc/shared/genCollectedHeap.cpp	2018-12-11 20:59:07.144826414 +0100
@@ -575,15 +575,7 @@
     bool old_collects_young = complete && !ScavengeBeforeFullGC;
     bool do_young_collection = !old_collects_young && _young_gen->should_collect(full, size, is_tlab);
 
-    FormatBuffer<> gc_string("%s", "Pause ");
-    if (do_young_collection) {
-      gc_string.append("Young");
-    } else {
-      gc_string.append("Full");
-    }
-
     GCTraceCPUTime tcpu;
-    GCTraceTime(Info, gc) t(gc_string, NULL, gc_cause(), true);
 
     gc_prologue(complete);
     increment_total_collections(complete);
@@ -602,6 +594,8 @@
         prepared_for_verification = true;
       }
 
+      GCTraceTime(Info, gc) t("Pause Young", NULL, gc_cause(), true);
+
       collect_generation(_young_gen,
                          full,
                          size,
@@ -637,6 +631,7 @@
         collect_generation(_old_gen, full, size, is_tlab, run_verification && VerifyGCLevel <= 1, do_clear_all_soft_refs, true);
       } else {
         // No young GC done. Use the same GC id as was set up earlier in this method.
+        GCTraceTime(Info, gc) t("Pause Full", NULL, gc_cause(), true);
         collect_generation(_old_gen, full, size, is_tlab, run_verification && VerifyGCLevel <= 1, do_clear_all_soft_refs, true);
       }