Request for Review (xs) : 8038928 - gc/g1/TestGCLogMessages.java fail with "[Evacuation Failure' found"

[Jon Masamitsu]

The requirement that an evacuation failure not happen during this
test is based on the expected behavior of the GC and is not a
required behavior.  In some instance the evacuation failure will
happen, but it is a not a  GC failure if it does and is only an
unexpected path being followed.

The test is not reliable but before removing it, I've made
some changes to try and save it.  I've modified the
test to slow down the allocations and changed the allocation to
allocate smaller objects (which also has a side effect of slowing
allocations).   The goal is to detect gross breakages of
evacuation failure while risking only very, very rare spurious
failures.

I had reproduced the failure with the unmodified test and it
would fail within 30 minutes.  With the modifications, I haven't
seen the failure in a day of testing.

If the modifications don't work, I'll remove the test.

http://cr.openjdk.java.net/~jmasa/8038928/webrev.00/

https://bugs.openjdk.java.net/browse/JDK-8038928

Thanks.

Jon