RFR: 8276252: java/nio/channels/Channels/TransferTo.java failed with OOM java heap space error

[Mark Sheppard]

On Wed, 3 Nov 2021 16:01:43 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>>> Hello Brian, should this also perhaps set the `-Xmx` value to a higher value or is the current VM defaults for max heap size on all VMs expected to be big enough for this test?
>> 
>> This may be helpful as this test needs to do some big transfer. For the specific OOME sighting then I suspect it may be more to do with how the tests are run. From what I can tell, it's running a very large group of tests and it's likely that the agent VM has been running for a long time. It could be that other tests that ran previously in this VM have left things behind.
>
> The version of the test proposed here passes with the command line option `-Xmx512M`, so if the default maximum heap size is really half the physical memory then I don't think it is necessary to set `-Xmx`.

on the machine env where the failure has occurred we see that JVM has default heap size at 30GB and the machine has physical memory at 762GB

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PR: https://git.openjdk.java.net/jdk/pull/6219