RFC 7038914: VM could throw uncaught OOME in ReferenceHandler thread

[David Holmes]

On 9/05/2013 7:18 PM, Peter Levart wrote:
> On 05/09/2013 07:53 AM, David Holmes wrote:
>> Have you instrumented the code to verify that the test actually
>> triggers an OOME?
>
> Without the patch, the test always throws OOME in lock.wait() and kills
> the thread. At least in all executions I tried (100s) it did the same.

How many different platforms could you try?

> The test might pass without a patch only perhaps when TLABs are used.
> The default is: -XX:-UseTLAB right? Perhaps it should be specified
> explicitly...

UseTLAB is true by default on most platforms:

./cpu/x86/vm/c1_globals_x86.hpp:define_pd_global(bool, UseTLAB, 
              true );
./cpu/x86/vm/c2_globals_x86.hpp:define_pd_global(bool, UseTLAB, 
              true);
./cpu/zero/vm/shark_globals_zero.hpp:define_pd_global(bool,     UseTLAB, 
                      true );
./cpu/sparc/vm/c2_globals_sparc.hpp:define_pd_global(bool, UseTLAB, 
                  true);
./cpu/sparc/vm/c1_globals_sparc.hpp:define_pd_global(bool, UseTLAB, 
                  true );

I don't expect the test to be absolutely foolproof on every platform but 
it would be good to know it actually catches the bug on our test systems 
:) Something Thomas should be able to test I hope.

Thanks,
David

> Regards, Peter
>