[11u] RFC: Update Graal in OpenJDK 11 Updates?

[Langer, Christoph]

Hi Gil,

> -----Original Message-----
> From: Gil Tene <gil at azul.com>
> Sent: Freitag, 13. März 2020 15:31
> To: Langer, Christoph <christoph.langer at sap.com>
> Cc: Andrew Hughes <gnu.andrew at redhat.com>; jdk-updates-
> dev at openjdk.java.net; Andrew Dinn <adinn at redhat.com>; Severin
> Gehwolf <sgehwolf at redhat.com>; Andrew Haley <aph at redhat.com>;
> Thomas Wuerthinger <thomas.wuerthinger at oracle.com>; Doug Simon
> <doug.simon at oracle.com>; Tom Rodriguez <tom.rodriguez at oracle.com>;
> Volker Simonis <volker.simonis at gmail.com>
> Subject: Re: [11u] RFC: Update Graal in OpenJDK 11 Updates?
> 
> 
> 
> Sent from my iPad
> 
> > On Mar 13, 2020, at 1:04 AM, Langer, Christoph
> <christoph.langer at sap.com> wrote:
> >
> > Hi Andrew, all,
> >
> >> -----Original Message-----
> >> From: Andrew Hughes <gnu.andrew at redhat.com>
> >> Sent: Donnerstag, 12. März 2020 19:27
> >> To: Langer, Christoph <christoph.langer at sap.com>; jdk-updates-
> >> dev at openjdk.java.net; Andrew Dinn <adinn at redhat.com>; Severin
> >> Gehwolf <sgehwolf at redhat.com>; Andrew Haley <aph at redhat.com>;
> >> Thomas Wuerthinger <thomas.wuerthinger at oracle.com>; Doug Simon
> >> <doug.simon at oracle.com>; Tom Rodriguez
> <tom.rodriguez at oracle.com>;
> >> Volker Simonis <volker.simonis at gmail.com>
> >> Subject: Re: [11u] RFC: Update Graal in OpenJDK 11 Updates?
> >>
> >>
> >>
> >>> On 12/03/2020 12:03, Langer, Christoph wrote:
> >>> Hi all,
> >>>
> >>> as you may or may not know, the GraalVM Community Edition (CE)
> >> supports OpenJDK 11 update releases. In order to do that, there exists a
> >> clone of the OpenJDK repository in the GraalVM GitHub space [0]. This
> fork,
> >> however, contains several additional patches, obviously mainly in the area
> of
> >> JVMCI and the Graal compiler. There seems to be a certain interest of the
> >> involved parties, that is, the GraalVM community, Oracle Labs and
> probably
> >> also the OpenJDK community, to keep these repositories as close as
> possible.
> >>>
> >>> One motivation could be to allow building of GraalVM native images
> from
> >> OpenJDK distributions, such as mentioned in a GitHub issue raised against
> >> the graal project [1].
> >>>
> >>> Another motivation probably comes from the Graal community to
> reduce
> >> the maintenance effort from merging the OpenJDK changes.
> >>>
> >>> Furthermore, it has been policy in the OpenJDK 11 Updates project to try
> to
> >> follow what Oracle is doing in their JDK 11 LTS update releases. Lately,
> there
> >> obviously have been backports for JVMCI and Graal which completely
> don't
> >> match with the current state of OpenJDK 11u. When researching this I
> >> learned that the prerequisite of these kind of changes is a larger update
> of
> >> JVMCI and Graal. The basis for this change could be a commit from the
> labs-
> >> openjdk-11 Graal repository [2]. This would update JVMCI and Graal to
> the
> >> state of OpenJDK 13. More details can be taken out of the conversation of
> >> the GitHub issue [1].
> >>>
> >>> I took this change, applied it to OpenJDK 11u-dev, resolved some
> conflicts
> >> and made sure it builds on all platforms (that we support in the SAP
> team). A
> >> prerequisite would also be a backport of JDK-8208686, at least the hotspot
> >> part of it, as provided in [4]. The Graal/Java parts of JDK-8208686 are
> >> contained in [3]. With this work applied, regression testing looks quite
> >> promising. There are a few test failures in the NMT area, some crashes
> with
> >> aot and a few minor Graal related test errors, but nothing that couldn't be
> >> solved with too much of effort, I guess. But I can't make any judgement
> on
> >> the state of the Graal compiler itself, since we don't have much test
> coverage
> >> for that in our infrastructure.
> >>>
> >>> However, the main point for me is to get a discussion started. First of all
> it is
> >> about whether we want to have this kind of update at all in OpenJDK 11
> >> Updates? If so, I'd need some help by people with expertise and test
> >> infrastructure for the Graal related part. That's nothing we can cover in
> the
> >> SAP team right now. If we decide against this update, we'll have give up
> our
> >> policy about following the Oracle 11 Updates for JVMCI/Graal.
> >>>
> >>> Looking forward to get input about this.
> >>>
> >>> Thanks and best regards
> >>> Christoph
> >>>
> >>> [0] https://github.com/graalvm/labs-openjdk-11/
> >>> [1] https://github.com/oracle/graal/issues/2196
> >>> [2] https://github.com/graalvm/labs-openjdk-
> >> 11/commit/fbbdf5f15300716110d2ac9b9bd7f70b03b35a7d
> >>> [3] http://cr.openjdk.java.net/~clanger/webrevs/graal13.11u/
> >>> [4] http://cr.openjdk.java.net/~clanger/webrevs/8208686.11u/
> >>>
> >>
> >> I'm aware of these changes for Graal and have been working on getting
> >> some of them into OpenJDK 11u.
> >>
> >> I don't think we should just apply these monolithic commits, but instead
> >> work out the relevant issues in OpenJDK 13 being backported and do it
> >> correctly. We want 11u to be as maintainable as possible.
> >
> > I've got some sympathy with that approach. We can certainly have a look to
> identify the single changes and try to apply them one by one... It'll probably
> also help to identify the sources of regressions when we run into some.
> >
> > But, the general question that needs to be answered before is: Do we
> want this to happen at all? Any opinions/thoughts?
> 
> Can you elaborate on what we believe the Oracle 11u has done so far on this
> matter?

In short, I believe Graal and JVMCI in Oracle 11u was updated to the JDK13 level. And from there on further patches have been backported.

The Graal/JVMCI update as a monolith would probably look like this: https://github.com/graalvm/labs-openjdk-11/commit/fbbdf5f15300716110d2ac9b9bd7f70b03b35a7d.
And additional backports come on top, like most of the 23 items left in this query: https://bugs.openjdk.java.net/issues/?filter=37811 

Best regards
Christoph