[11u] Backport of fix for CDS and JVM-TI agent crash ?

Mon Jun 24 05:58:46 UTC 2019

Hi Jiangli,

thank you very much for this update and all the effort in this. Seems like a lot of work but for sure the gain will be nice. ��
I hope all of the dependent items are appropriate for JDK11 u backport. I guess I won’t be able to help you too much with these as I’m currently focusing on the stuff that Oracle has brought to 11.0.5. This also contains quite some non-trivial ones…

Best regards
Christoph

From: Jiangli Zhou <jianglizhou at google.com>
Sent: Sonntag, 23. Juni 2019 22:34
To: Langer, Christoph <christoph.langer at sap.com>
Cc: Michael Rasmussen <Michael.Rasmussen at roguewave.com>; jdk-updates-dev at openjdk.java.net; Ioi Lam <ioi.lam at oracle.com>
Subject: Re: [11u] Backport of fix for CDS and JVM-TI agent crash ?

Hi Christoph,

Just an update on this effort:

https://bugs.openjdk.java.net/browse/JDK-8210926 has been backported to 11u. I've also labeled all dependencies (with google-interest) related to JDK-8212200 and JDK-8213250, including additional bug fixes and enhancements pulled in for the dependencies. There are total 33 bug fixes and enhances. I'll go through them to backport to 11u. Please feel free to take any of them if you can.

With this set of fixes and enhancements, it will bring in the startup performance improvements using Java object archiving (enabled with the default CDS) to OpenJDK 11 update. Users will see a nice speedup with the JVM startup time.

Best regards,
Jiangli

On Wed, Jun 19, 2019 at 7:44 AM Jiangli Zhou <jianglizhou at google.com<mailto:jianglizhou at google.com>> wrote:
My pleasure��.

Best regards,
Jiangli

On Wed, Jun 19, 2019 at 12:43 AM Langer, Christoph <christoph.langer at sap.com<mailto:christoph.langer at sap.com>> wrote:
Hi Jiangli,

sounds good to me. Thanks for your effort with this ��

Cheers
Christoph

From: Jiangli Zhou <jianglizhou at google.com<mailto:jianglizhou at google.com>>
Sent: Mittwoch, 19. Juni 2019 00:49
To: Langer, Christoph <christoph.langer at sap.com<mailto:christoph.langer at sap.com>>
Cc: Michael Rasmussen <Michael.Rasmussen at roguewave.com<mailto:Michael.Rasmussen at roguewave.com>>; jdk-updates-dev at openjdk.java.net<mailto:jdk-updates-dev at openjdk.java.net>; Ioi Lam <ioi.lam at oracle.com<mailto:ioi.lam at oracle.com>>
Subject: Re: [11u] Backport of fix for CDS and JVM-TI agent crash ?

https://bugs.openjdk.java.net/browse/JDK-8210926 can be applied cleanly with no dependencies. I've added jdk11u-fix-request.

Best regards,
Jiangli

On Tue, Jun 18, 2019 at 3:25 PM Jiangli Zhou <jianglizhou at google.com<mailto:jianglizhou at google.com>> wrote:
Hi Christoph and others,

I did investigations for backporting the JDK-8212200 and JDK-8213250 changes. There are some dependencies on Java object archiving work. The cleanest way to handle the backports is to pull in all the dependencies one by one to OpenJDK 11. It helps minimize the merge changes. It also helps JVM startup time in JDK 11 by pulling in the additional optimizations. Thoughts from anyone?

Best regards,
Jiangli

On Tue, Jun 18, 2019 at 6:20 AM Langer, Christoph <christoph.langer at sap.com<mailto:christoph.langer at sap.com>> wrote:
Hi Jiangli,

thanks for taking this over. I tried to pick a few of the dependent fixes but it got too much for me. ��

Best regards
Christoph

From: Jiangli Zhou <jianglizhou at google.com<mailto:jianglizhou at google.com>>
Sent: Dienstag, 18. Juni 2019 01:14
To: Langer, Christoph <christoph.langer at sap.com<mailto:christoph.langer at sap.com>>
Cc: Michael Rasmussen <Michael.Rasmussen at roguewave.com<mailto:Michael.Rasmussen at roguewave.com>>; jdk-updates-dev at openjdk.java.net<mailto:jdk-updates-dev at openjdk.java.net>; Ioi Lam <ioi.lam at oracle.com<mailto:ioi.lam at oracle.com>>
Subject: Re: [11u] Backport of fix for CDS and JVM-TI agent crash ?

Hi Christoph,

I'll help out (maybe slow). JDK-8213250 has quite a few dependencies that needs to be backported first, but most can be done cleanly.

There is also the https://bugs.openjdk.java.net/browse/JDK-8210926, which I think should be backported to JDK 11 as well. The issue can surface up when the default CDS is used with JVMTI.

I'll start from the easy ones first.

Best regards,

Jiangli

On Mon, Jun 17, 2019 at 8:17 AM Langer, Christoph <christoph.langer at sap.com<mailto:christoph.langer at sap.com>> wrote:
Hi Michael,

I looked into backports for JDK-8212200 and JDK-8213250 but I'm not able to do them. The code level between current JDK11u hotspot and the jdk/jdk repository at the time the patches were pushed (JDK12) has diverged too much. So, it's not a simple resolve and test thing. People with more experience in that area will have to do it. I don't have the required expertise and also no time to dig deeper into it.

So, maybe somebody is willing to step up here - otherwise I'm afraid these bugs need to remain unfixed in OpenJDK 11 for the time being.

Best regards
Christoph

> -----Original Message-----
> From: Langer, Christoph
> Sent: Mittwoch, 20. März 2019 16:13
> To: 'Ioi Lam' <ioi.lam at oracle.com<mailto:ioi.lam at oracle.com>>
> Cc: jdk-updates-dev at openjdk.java.net<mailto:jdk-updates-dev at openjdk.java.net>; Michael Rasmussen
> <Michael.Rasmussen at roguewave.com<mailto:Michael.Rasmussen at roguewave.com>>
> Subject: RE: [11u] Backport of fix for CDS and JVM-TI agent crash ?
>
> Hi Ioi,
>
> thanks again for the update. I'll take care of these backports then.
>
> Thanks
> Christoph
>
> > -----Original Message-----
> > From: Ioi Lam <ioi.lam at oracle.com<mailto:ioi.lam at oracle.com>>
> > Sent: Dienstag, 19. März 2019 22:38
> > To: Langer, Christoph <christoph.langer at sap.com<mailto:christoph.langer at sap.com>>
> > Cc: jdk-updates-dev at openjdk.java.net<mailto:jdk-updates-dev at openjdk.java.net>; Michael Rasmussen
> > <Michael.Rasmussen at roguewave.com<mailto:Michael.Rasmussen at roguewave.com>>
> > Subject: Re: [11u] Backport of fix for CDS and JVM-TI agent crash ?
> >
> > The 3 issues that I wanted to backport were:
> >
> > Issue       BP-of   Synopsis
> > JDK-8212991 8212205 VM asserts after CDS archive has been unmapped
> > JDK-8213273 8213250 CDS archive creation aborts due to metaspace object
> > allocation failure
> > JDK-8213164 8212200 assert(on_stack()) failed when shared
> > java.lang.object is redefined by JVMTI agent
> >
> > They are all backport issues related to CDS with (fixVersion = 11-pool).
> > Only the last one is related to JVMTI, but the other 2 are kind of
> > serious as well. But due to reassignment, I wasn't able to do the
> > backport :-(
> >
> > Thanks
> > - Ioi
> >
> > On 3/18/19 2:08 PM, Langer, Christoph wrote:
> > > Hi Ioi,
> > >
> > > ok, thanks for that information.
> > >
> > > Can you let us know, what exactly these 3 bugs were, that should be
> > backported? I guess it's about JDK-8212200, JDK-8213182 which fixes a build
> > failure after the former one. And what's the 3rd issue?
> > >
> > > Thanks
> > > Christoph
> > >
> > >> -----Original Message-----
> > >> From: Ioi Lam <ioi.lam at oracle.com<mailto:ioi.lam at oracle.com>>
> > >> Sent: Montag, 18. März 2019 19:27
> > >> To: Langer, Christoph <christoph.langer at sap.com<mailto:christoph.langer at sap.com>>
> > >> Cc: jdk-updates-dev at openjdk.java.net<mailto:jdk-updates-dev at openjdk.java.net>; Michael Rasmussen
> > >> <Michael.Rasmussen at roguewave.com<mailto:Michael.Rasmussen at roguewave.com>>
> > >> Subject: Re: [11u] Backport of fix for CDS and JVM-TI agent crash ?
> > >>
> > >> Hi Christoph, I have been reassigned (and I've removed myself as the
> > >> assigned engineer for those bugs) so I think it's best for the openjdk
> > >> community to pick up these backports.
> > >>
> > >> Thanks
> > >>
> > >> - Ioi
> > >>
> > >> On 3/17/19 11:46 PM, Langer, Christoph wrote:
> > >>> Hi Ioi,
> > >>>
> > >>> I'd like to ping you again on this one. What are your current plans on
> > >> backporting https://bugs.openjdk.java.net/browse/JDK-8212200 and
> > >> whatever needs to go with it? Ideally you still want to do it, but if not I'd
> > >> appreciate if you could let us know.
> > >>> Thanks a lot in advance
> > >>> Christoph
> > >>>
> > >>>
> > >>>> -----Original Message-----
> > >>>> From: jdk-updates-dev <jdk-updates-dev-
> > bounces at openjdk.java.net<mailto:bounces at openjdk.java.net>>
> > >> On
> > >>>> Behalf Of Ioi Lam
> > >>>> Sent: Dienstag, 29. Januar 2019 01:33
> > >>>> To: jdk-updates-dev at openjdk.java.net<mailto:jdk-updates-dev at openjdk.java.net>
> > >>>> Subject: Re: Backport of fix for CDS and JVM-TI agent crash ?
> > >>>>
> > >>>> There are CDS 3 bugs that I plan to backport to 11. I hope to post the
> > >>>> requests this week.
> > >>>>
> > >>>> https://bugs.openjdk.java.net/issues/?filter=36209
> > >>>>
> > >>>> Thanks
> > >>>>
> > >>>> - Ioi
> > >>>>
> > >>>> On 1/28/19 8:35 AM, Lindenmaier, Goetz wrote:
> > >>>>> Hi,
> > >>>>>
> > >>>>> The fact a downport bug was opened does not matter,
> > >>>>> you could still flag jdk11u-fix-request and just push it
> > >>>>> if approved.  This bug will then be closed as it is flagged 11-pool.
> > >>>>>
> > >>>>> More gentle it would be to ask Ioi what's going on ...
> > >>>>>
> > >>>>> Best regards,
> > >>>>>      Goetz.
> > >>>>>
> > >>>>>> -----Original Message-----
> > >>>>>> From: jdk-updates-dev <jdk-updates-dev-
> > >> bounces at openjdk.java.net<mailto:bounces at openjdk.java.net>>
> > >>>> On
> > >>>>>> Behalf Of Volker Simonis
> > >>>>>> Sent: Monday, January 28, 2019 5:02 PM
> > >>>>>> To: Michael Rasmussen <Michael.Rasmussen at roguewave.com<mailto:Michael.Rasmussen at roguewave.com>>
> > >>>>>> Cc: jdk-updates-dev at openjdk.java.net<mailto:jdk-updates-dev at openjdk.java.net>
> > >>>>>> Subject: Re: Backport of fix for CDS and JVM-TI agent crash ?
> > >>>>>>
> > >>>>>> On Mon, Jan 28, 2019 at 4:17 PM Michael Rasmussen
> > >>>>>> <Michael.Rasmussen at roguewave.com<mailto:Michael.Rasmussen at roguewave.com>> wrote:
> > >>>>>>> Hi,
> > >>>>>>>
> > >>>>>>> I was wondering if there are any plans to backport
> > >>>>>> https://bugs.openjdk.java.net/browse/JDK-8212200 to jdk11u.
> > >>>>>>> I can see https://bugs.openjdk.java.net/browse/JDK-8213164 has
> > >> been
> > >>>>>> created, but don't know if there are any active plans to actually do
> it?
> > >>>>>> Hi Michael,
> > >>>>>>
> > >>>>>> I actually don't really understand what this means. Usually, you do
> a
> > >>>>>> down-port by first requesting it on the original bug by applying a
> > >>>>>> "jdk<release>u-fix-request" tag. Once the downport will be
> > approved
> > >>>>>> (by application of a "jdk<release>u-fix-yes" tag), the
> corresponding
> > >>>>>> fix can be pushed to the updates repository. This push
> automatically
> > >>>>>> triggers the creation of the corresponding backport issue in JBS.
> > >>>>>>
> > >>>>>> I don't know what it means for the downport process [1] if
> > somebody
> > >>>>>> (apparently manually) creates a backport issue like
> > >>>>>> https://bugs.openjdk.java.net/browse/JDK-8213164 ?
> > >>>>>>
> > >>>>>> Regards,
> > >>>>>> Volker
> > >>>>>>
> > >>>>>> [1] http://openjdk.java.net/projects/jdk-updates/approval.html
> > >>>>>>
> > >>>>>>> Kind regards
> > >>>>>>> /Michael