This issue was fixed in JDK-8034263. Unfortunately it looks like it happened again.

 stderr: [Exception in thread "main" java.lang.RuntimeException: Unexpected count of notification #0 count = 2 but expected to be 1
at LowMemoryTest$TestListener.checkResult(LowMemoryTest.java:125)
at LowMemoryTest$TestMain.main(LowMemoryTest.java:220)
]
 exitValue = 1

java.lang.RuntimeException: Expected to get exit value of [0]

at jdk.testlibrary.OutputAnalyzer.shouldHaveExitValue(OutputAnalyzer.java:353)
at RunUtil.runTest(RunUtil.java:78)
at RunUtil.runTestClearGcOpts(RunUtil.java:42)
at LowMemoryTest.main(LowMemoryTest.java:77)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.sun.javatest.regtest.MainWrapper$MainThread.run(MainWrapper.java:94)
at java.lang.Thread.run(Thread.java:745)