We see intermittent errors in JDK 8 with this test where the expected usage number read from the MemoryPool does not match that read from perfmemory.

This test is racy since the test itself may invoke the metaspace allocator, and also because concurrent metaspace allocation can happen. It can be stabilized somewhat, however: both JDK-8148483 and JDK-8151460 improved the original test for JDK 9.