RFR: 8040935: -XX:+AggressiveOpts broken: GC triggered before VM initialization completed on several tests
stefan.johansson at oracle.com
Thu Jan 15 14:12:44 UTC 2015
On 2015-01-15 00:49, Stefan Johansson wrote:
> Hi Kim,
> On 2015-01-14 19:13, Kim Barrett wrote:
>> On Jan 12, 2015, at 5:01 AM, Stefan Johansson
>> <stefan.johansson at oracle.com> wrote:
>>> Please review this testfix to avoid the following issue:
>>> Making the test a driver test to avoid dealing with externally
>>> specified flags. One problematic flag is AggressiveOpts, it causes
>>> the VM to allocate more stuff during startup and that together with
>>> UseNUMA the eden space gets to little to handle all startup
>>> allocations. This will in turn lead to a GC being triggered before
>>> initialization is finished, and because of that failing the test.
>>> * Tested via JPRT
>> Summary: Changed test to not be affected by external options.
>> I'm not sure I like this approach to resolving the bug. I think it
>> results in many potentially interesting configurations never being
>> tested, e.g. this tests with one and only one GC, the default GC. It
>> ignores the nightly build cycling through various configurations to
>> increase test coverage.
> Thanks for taking a look at this. I see your point and think we should
> do something better. The test was originally written to test a
> specific regression we had when starting with -Xmx8m and -XX:+UseNUMA
> with the default collector, but that doesn't mean we shouldn't test it
> for the others as well. I'm not sure if we have any NUMA support for
> the other collectors today, but no harm in testing that the option
> doesn't cause any problems.
> I see two ways of improving the coverage, one would be to use
> @requires to say that AggressiveOpts can't be true, but that will
> still leave the possibility to set other options that might push us
> over the limit of allocations during startup. The other way would be
> to extend the test to run with all collectors explicitly, but ignore
> any options passed in. This would of course still have less coverage
> than today, but at least all collectors would be covered.
> I would prefer the second one, it would be robust and the coverage
> would be ok.
Updated webrev that tests all GCs:
Verified that the test still passes when run through JPRT.
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