Question regarding 8248521: TestVerifyIterativeGVN.java is failing with timeout

[Lindenmaier, Goetz]

Hi Christian, 

Thanks for your explanation. 
I can confirm that it never timed out in 15 in our test infra.
It might start again in case code changes again, but 
that is the risk with any test.
(We never saw the stack overflow, though.)

Best regards,
  Goetz.


> -----Original Message-----
> From: Christian Hagedorn <christian.hagedorn at oracle.com>
> Sent: Friday, July 10, 2020 10:28 AM
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; 'Fairoz Matte'
> <fairoz.matte at oracle.com>
> Cc: hotspot-compiler-dev at openjdk.java.net
> Subject: Re: Question regarding 8248521: TestVerifyIterativeGVN.java is
> failing with timeout
> 
> Hi Goetz
> 
> As Fairoz has mentioned, JDK-8246203 changed the algorithm slightly such
> that it needs now more time for the verification (we check more nodes
> than before).
> 
> JDK-8246203 originally only happened in JDK-11 with
> -XX:+VerifyIterativeGVN where a stack overflow crash occurred with a
> more or less HelloWorld test (the old algorithm as a recursive one). It
> turned out that with JDK-11 it compiled a specific big method which
> generated quite a lot of nodes in a chain which let it crash. However,
> with JDK-15 (and 16), this method was not compiled anymore as part of a
> HelloWorld test. It probably got changed since JDK-11 or is not called
> anymore when starting up. Therefore, we concluded that it must be an 11
> only issue and just increased the timeout for the test as we have not
> seen timing it out in JDK-15 or 16.
> 
> Best regards,
> Christian
> 
> On 10.07.20 10:06, Lindenmaier, Goetz wrote:
> > Hi Fairoz,
> >
> > Thanks for the info.
> >
> > It's still unclear to me why the algorithm takes longer in 11
> > than in 15 ... but no matter.
> >
> > Best regards,
> >    Goetz.
> >
> > From: Fairoz Matte <fairoz.matte at oracle.com>
> > Sent: Friday, July 10, 2020 10:01 AM
> > To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> > Cc: hotspot-compiler-dev at openjdk.java.net
> > Subject: RE: Question regarding 8248521: TestVerifyIterativeGVN.java is
> failing with timeout
> >
> > Hi Goetz,
> >
> > This issue is only applicable to 11u.
> > After the fix of JDK-8246203,  which changed the algorithm for the
> verification used with VerifyIterativeGVN (takes more time)
> > We have adjusted timeout to 1200 from 600.
> >
> > Thanks,
> > Fairoz
> >
> > From: Lindenmaier, Goetz
> <goetz.lindenmaier at sap.com<mailto:goetz.lindenmaier at sap.com>>
> > Sent: Friday, July 10, 2020 12:11 PM
> > To: Fairoz Matte
> <fairoz.matte at oracle.com<mailto:fairoz.matte at oracle.com>>
> > Cc: hotspot-compiler-dev at openjdk.java.net<mailto:hotspot-compiler-
> dev at openjdk.java.net>
> > Subject: Question regarding 8248521: TestVerifyIterativeGVN.java is failing
> with timeout
> >
> > Hi Fairoz,
> >
> > we also see this test timing out on mac. But only so with
> > jdk11u.
> > Do you mind sharing how you fixed this? Did you just increase
> > the timeout, or did you figure out why this fails on mac in 11u?
> >
> > Thanks,
> >    Goetz
> >