Without patch:

Scenario 'org.eclipse.jdt.ui.tests.performance.views.TypeHierarchyPerfTest#testOpenObjectHierarchy()' (average over 1 samples):
  Used Java Heap: 594.55K
  Working Set: 2.54M
  Committed: 2.61M
  Working Set Peak: 2.57M
  Elapsed Process: 2.07 s
  Kernel time: 351 ms
  Page Faults: 1.28K
  CPU Time: 2.03 s
  GDI Objects: 93

Scenario 'org.eclipse.jdt.ui.tests.performance.views.TypeHierarchyPerfTest#testOpenCollHierarchy()' (average over 1 samples):
  Used Java Heap: 2.35M
  Working Set: 1.8M
  Committed: 944K
  Working Set Peak: 1.84M
  Elapsed Process: 841 ms
  Kernel time: 140 ms
  Page Faults: 524
  CPU Time: 821 ms
  GDI Objects: 12

Scenario 'org.eclipse.jdt.ui.tests.performance.views.TypeHierarchyPerfTest#testOpenObjectHierarchy2()' (average over 1 samples):
  Used Java Heap: -1178024
  Working Set: 504K
  Committed: 836K
  Working Set Peak: 580K
  Elapsed Process: 961 ms
  Kernel time: 50 ms
  Page Faults: 227
  CPU Time: 932 ms
  GDI Objects: 0

With patch:

Scenario 'org.eclipse.jdt.ui.tests.performance.views.TypeHierarchyPerfTest#testOpenObjectHierarchy()' (average over 1 samples):
  Used Java Heap: -1591792
  Working Set: 3.55M
  Committed: 2.94M
  Working Set Peak: 2.99M
  Elapsed Process: 2.09 s
  Kernel time: 321 ms
  Page Faults: 1.38K
  CPU Time: 1.94 s
  GDI Objects: 93

Scenario 'org.eclipse.jdt.ui.tests.performance.views.TypeHierarchyPerfTest#testOpenCollHierarchy()' (average over 1 samples):
  Used Java Heap: 1.54M
  Working Set: 1'004K
  Committed: 1.02M
  Working Set Peak: 1'004K
  Elapsed Process: 881 ms
  Kernel time: 130 ms
  Page Faults: 287
  CPU Time: 851 ms
  GDI Objects: 12

Scenario 'org.eclipse.jdt.ui.tests.performance.views.TypeHierarchyPerfTest#testOpenObjectHierarchy2()' (average over 1 samples):
  Used Java Heap: -1012640
  Working Set: 1.11M
  Committed: 3.21M
  Working Set Peak: 108K
  Elapsed Process: 891 ms
  Kernel time: 60 ms
  Page Faults: 358
  CPU Time: 871 ms
  GDI Objects: 0