RFR (XS) 8215329: Modify ZGC requirement for HeapMonitorThreadTest.java

[JC Beyler]

Thanks all, tested & pushed.

@Per: let me know when you resolve your bug and if you want me to do
anything from my side

On Thu, Dec 13, 2018 at 10:25 AM serguei.spitsyn at oracle.com <
serguei.spitsyn at oracle.com> wrote:

> +1
>
> Thanks,
> Serguei
>
>
> On 12/13/18 09:40, Alex Menkov wrote:
> > +1
> >
> > --alex
> >
> > On 12/13/2018 08:59, JC Beyler wrote:
> >> Hi Per,
> >>
> >> Thanks for the messages and review :-). I believe that actually what
> >> happened was that when JDK11 was close to release both ZGC and
> >> HeapMonitoring tried to get in. In a last effort, we turned off this
> >> test for ZGC as it was showing test failures for ZGC. It's a bit
> >> fuzzy to be honest (I was also on paternity leave and Serguei &
> >> Jeremy were helping out here). But anyway, what seems to be true now
> >> is that you found a bug (yeah I guess?) and we can remove
> >> the @requires once you fix your race.
> >>
> >> Therefore, could I please get another review to update the @requires
> >> to be correct then until then?
> >>
> >> (@Per: if you want, I can update the test once it's done; either
> >> assign a JBS bug to me or send me an email)
> >>
> >> Thanks,
> >> Jc
> >>
> >> On Thu, Dec 13, 2018 at 4:47 AM Per Liden <per.liden at oracle.com
> >> <mailto:per.liden at oracle.com>> wrote:
> >>
> >>     Hi, me again ;)
> >>
> >>     I think I've found the root cause of this. There's a tiny race in
> >> the
> >>     ZGC allocation path, which can lead to pre-mature OOME being thrown.
> >>     It's not trivial to fix, so I suggest you go ahead with your
> >> original
> >>     patch (Looks good btw), and I'll file a separate bug to fix the ZGC
> >>     issue (and update this test to run with ZGC again).
> >>
> >>     cheers,
> >>     Per
> >>
> >>     On 12/13/2018 12:21 PM, Per Liden wrote:
> >>      > Hi again,
> >>      >
> >>      > I ran this test some more and managed to get an OOME even with a
> >>     768M
> >>      > heap. I'm getting a bit suspicious that something else is wrong
> >>     here.
> >>      > Let me dig into this some more and see if I can understand what
> >>     the real
> >>      > issue is.
> >>      >
> >>      > cheers,
> >>      > Per
> >>      >
> >>      > On 12/13/2018 10:31 AM, Per Liden wrote:
> >>      >> Hi JC,
> >>      >>
> >>      >> What's the reason to exclude ZGC from this test to begin
> >> with? From
> >>      >> what I can tell, it's because the test is using a slightly too
> >>     small
> >>      >> heap, or are there some other reason? I ran it a few times using
> >>      >> various heap sizes and the test passes with ZGC when using
> >> anything
> >>      >> above 612M. So if we instead just dump the heap size a bit,
> >> then we
> >>      >> get test coverage with ZGC too. I picked 768M here to have some
> >>      >> headroom in case the exact limit is run-to-run dependent.
> >>      >>
> >>      >> diff --git
> >>      >>
> >>
> a/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java
> >>
> >>      >>
> >>
> b/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java
> >>
> >>      >>
> >>      >> ---
> >>      >>
> >>
> a/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java
> >>
> >>      >>
> >>      >> +++
> >>      >>
> >>
> b/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorThreadTest.java
> >>
> >>      >>
> >>      >> @@ -29,8 +29,7 @@
> >>      >>    * @build Frame HeapMonitor ThreadInformation
> >>      >>    * @summary Verifies the JVMTI Heap Monitor Thread information
> >>     sanity.
> >>      >>    * @compile HeapMonitorThreadTest.java
> >>      >> - * @run main/othervm/native -Xmx512m -agentlib:HeapMonitorTest
> >>      >> MyPackage.HeapMonitorThreadTest
> >>      >> - * @requires !vm.gc.Z
> >>      >> + * @run main/othervm/native -Xmx768m -agentlib:HeapMonitorTest
> >>      >> MyPackage.HeapMonitorThreadTest
> >>      >>    */
> >>      >>
> >>      >>   import java.util.List;
> >>      >>
> >>      >> cheers,
> >>      >> Per
> >>      >>
> >>      >> On 12/13/2018 05:44 AM, JC Beyler wrote:
> >>      >>> Hi all,
> >>      >>>
> >>      >>> When working on another webrev, I saw this problem:
> >>      >>>
> >>      >>> Webrev:
> http://cr.openjdk.java.net/~jcbeyler/8215329/webrev.00/
> >>      >>> Bug: https://bugs.openjdk.java.net/browse/JDK-8215329
> >>      >>>
> >>      >>> (Basically, from what I understood from an email from Per
> >> Liden:
> >>      >>>     - @requires !vm.gc.Z -> ZGC is built in the JDK
> >>      >>>     - @requires vm.gc != "Z" -> ZGC is being used for the
> >> runtime
> >>      >>> )
> >>      >>>
> >>      >>> Thanks,
> >>      >>> Jc
> >>
> >>
> >>
> >> --
> >>
> >> Thanks,
> >> Jc
>
>

-- 

Thanks,
Jc
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