Test issue? The use of -XX:-UseGCOverheadLimit could be relevant here.

Java options: -d64 -server -Xmixed -XX:MaxRAMFraction=8 -XX:+CreateMinidumpOnCrash -XX:+UseG1GC -XX:MaxRAMFraction=8 -XX:-UseGCOverheadLimit

Output from the test:

Stress time: 30 seconds
Stress iterations factor: 1
Stress threads factor: 1
Stress runs factor: 1
Max memory: 1035993088
Sleep time: 500
Iterations: 0
Number of threads: 4
Seed: 1421491749267
Run GC thread: false
Run mem diag thread: false
Run forever: false
Starting Thread[gc.lock.LockerTest$Worker@36aa7bc2,5,main]
Starting Thread[gc.lock.LockerTest$Worker@26f0a63f,5,main]
Starting Thread[gc.lock.LockerTest$Worker@4361bd48,5,main]
Starting Thread[gc.lock.LockerTest$Worker@53bd815b,5,main]
Unexpected exception during the run.
java.lang.OutOfMemoryError: Java heap space

Stacktrace:
Exception in thread "main" nsk.share.TestFailure: Test exit code: 97
at nsk.share.test.Tests$TestRunner.execute(Tests.java:71)
at nsk.share.test.Tests$TestRunner.run(Tests.java:77)
at nsk.share.gc.GC.runTest(GC.java:95)
at gc.lock.LockerTest.main(LockerTest.java:58)