When fixing JDK-8129590, -Xmx256m was added to avoid running out of memory. The reason for running out of memory was that the server only had 512mb ram and the max heap size was ergonomically set to the same as the initial heap size. The test need somewhat more memory than the initial heap size and therefor runs OOM.

The test specifies an initial heap size and a new generation size already and seems to have good notion of how much memory is really used. To allow the test to run on smaller servers it would be nice if the test could use less memory but still test what it should.