RFR(S): 8240634: event/runtime/TestMetaspaceAllocationFailure.java times out

[Thomas Stüfe]

Hi Mikhailo,

looks good to me. Thanks for taking my suggestions.

Cheers, Thomas

On Thu, Mar 26, 2020 at 1:28 AM <mikhailo.seledtsov at oracle.com> wrote:

> Here is an updated webrev:
> http://cr.openjdk.java.net/~mseledtsov/8240634.01/
>
> On 3/25/20 4:55 PM, mikhailo.seledtsov at oracle.com wrote:
> > Erik, Thomas,
> >
> >   Thank you for reviewing this change. See my comment inline:
> >
> > On 3/25/20 7:06 AM, Thomas Stüfe wrote:
> >> Hi Mikhailo, Erik,
> >>
> >> You should not need the additional -XX:MaxMetaspaceSize=200M. As a
> >> rule of thumb, in compressed class space, each class takes about 1K
> >> (bit less actually) so 200M give you room for about 200000 - 250000
> >> classes to load before OOM. I'd say that is way too much for this
> >> test. You just want enough to load the base jdk and get the test
> >> running and then you want to hit OOM quickly.
> >>
> >> I tested the test with CompressedClassSpaceSize=10M (which would give
> >> us about 10000 classes) and that still worked fine, so I think you
> >> could just drastically lower CompressedClassSpaceSize.
> > Thank you for detailed explanation. For the second test case (second
> > @run statement), I have set the CompressedClassSpaceSize to 10M. I ran
> > the test many times on Linux, Windows and Mac, and it works well.
> >>
> >> Also why the Thread.sleep(100) in the loop? Maybe it would make more
> >> sense to make the fill-loop tight or with only minimal sleep time,
> >> and instead have a loop at the outside waiting for the even to arrive?
> >
> > I have removed the sleep, and it seems to work fine.
> >
> > Since these both are trivial updates, I will go ahead and integrate
> > the change.
> >
> >
> > I also agree with Erik, if this test keeps being unstable I am
> > inclined to remove it.
> >
> >
> > Thank you,
> >
> > Misha
> >
> >>
> >> Cheers, Thomas
> >>
> >> On Wed, Mar 25, 2020 at 1:24 PM Erik Gahlin <erik.gahlin at oracle.com
> >> <mailto:erik.gahlin at oracle.com>> wrote:
> >>
> >>     Hi Misha,
> >>
> >>     Looks OK
> >>
> >>     Relying on OOM and parameters being correct to trigger the event
> >> seem
> >>     fragile, but let's try this and if it fails again, let's remove
> >>     the test
> >>     or come up with another approach.
> >>
> >>     Thanks
> >>     Erik
> >>
> >>     On 2020-03-18 02:24, mikhailo.seledtsov at oracle.com
> >>     <mailto:mikhailo.seledtsov at oracle.com> wrote:
> >>     > This test timed out occasionally, about 1/100 runs, on Linux only.
> >>     > Please review this change that mitigates occasional test failure
> >>     > by limiting the number of iterations attempting to fill up
> >>     metaspace,
> >>     > and throwing SkippedException when the max number
> >>     > of iterations is reached.
> >>     >
> >>     >     JBS: https://bugs.openjdk.java.net/browse/JDK-8240634
> >>     >     Webrev: http://cr.openjdk.java.net/~mseledtsov/8240634.00/
> >>     >     Testing:
> >>     >         Ran 100 times on Linux, 1 skipped, rest PASS
> >>     >
> >>     >
> >>     > Thank you,
> >>     > Misha
> >>     >
> >>
>