There's very little information in the test log to see what happened. Since this bug is not easily reproduced, we should add more logging in the test to diagnose the failures.

[1] -Xlog:metaspace*=debug should be added to test/hotspot/jtreg/runtime/cds/SharedBaseAddress.java

[2] virtualMemoryTracker.cpp should use Unified Logging to log the changes in _reserved_regions.