Java garbage collection logging with '0.00' user times

Issue

• GC logging initially shows realistic user times:

104.892: [Full GC 1684M->1061M(3584M), 5.2641570 secs]
...
   [Eden: 0.0B(174.0M)->0.0B(179.0M) Survivors: 5120.0K->0.0B Heap: 1684.0M(3584.0M)->1061.9M(3584.0M)]
...
 [Times: user=7.41 sys=0.03, real=5.26 secs]

• After some period of time, all user times become 0.00:

51678.186: [GC pause (young)
...
   [Eden: 1097.0M(1171.0M)->0.0B(163.0M) Survivors: 18.0M->16.0M Heap: 2952.7M(3584.0M)->1854.3M(3584.0M)]
...
 [Times: user=0.00 sys=0.41, real=0.05 secs]