RFR(S) 8208658: Make CDS archived heap regions usable even if compressed oop encoding has changed

[Lindenmaier, Goetz]

Hi Ioi, Jinagli,

Thanks for your feedback! I will look into this and post a webrev. 
I'll open a bug myself.

Best regards
  Goetz.

> -----Original Message-----
> From: Ioi Lam <ioi.lam at oracle.com>
> Sent: Mittwoch, 29. August 2018 19:05
> To: Jiangli Zhou <jiangli.zhou at oracle.com>; Lindenmaier, Goetz
> <goetz.lindenmaier at sap.com>; Thomas Schatzl
> <thomas.schatzl at oracle.com>; hotspot-runtime-dev at openjdk.java.net
> runtime <hotspot-runtime-dev at openjdk.java.net>; hotspot-gc-dev
> <hotspot-gc-dev at openjdk.java.net>
> Subject: Re: RFR(S) 8208658: Make CDS archived heap regions usable even if
> compressed oop encoding has changed
> 
> How about creating a general purpose WB API that can query for all the
> SupportedGCs[] defined in src/hotspot/share/gc/shared/gcConfig.cpp?
> 
> Thanks
> 
> - Ioi
> 
> 
> On 8/29/18 9:43 AM, Jiangli Zhou wrote:
> > Hi Goetz,
> >
> > Adding WB_IsZGCIncludedInVmBuild() in whitebox sounds good. It might
> > be useful in other cases as well. Have you filed a bug for the
> > sharedStrings/IncompatibleOptions.java issue? If not, I can create one.
> >
> > Thanks,
> >
> > Jiangli
> >
> >
> > On 8/29/18 1:18 AM, Lindenmaier, Goetz wrote:
> >> Hi,
> >>
> >> I see appcds/sharedStrings/IncompatibleOptions.java failing since it
> >> was pushed. Now two more tests for this were added in 8208658.
> >>
> >> They fail because we build on linuxx86_64 without ZGC, but the test
> >> contains
> >> if (Platform.isLinux() && Platform.isX64()) {
> >>              testDump(1, "-XX:+UnlockExperimentalVMOptions",
> >> "-XX:+UseZGC", COOPS_DUMP_WARNING, true);
> >> }
> >>
> >> Should we implement WB_IsZGCIncludedInVmBuild() similar to
> >> WB_IsCDSIncludedInVmBuild()
> >> in whitebox?  This could be used instead.
> >> Or is there already functionality to test this better than checking
> >> the platforms?
> >>
> >> Best regards,
> >>    Goetz.
> >>
> >>
> >>
> >>> -----Original Message-----
> >>> From: hotspot-gc-dev <hotspot-gc-dev-bounces at openjdk.java.net> On
> >>> Behalf Of Ioi Lam
> >>> Sent: Mittwoch, 22. August 2018 17:30
> >>> To: Thomas Schatzl <thomas.schatzl at oracle.com>; Jiangli Zhou
> >>> <jiangli.zhou at oracle.com>; hotspot-runtime-dev at openjdk.java.net
> >>> runtime <hotspot-runtime-dev at openjdk.java.net>; hotspot-gc-dev
> >>> <hotspot-gc-dev at openjdk.java.net>
> >>> Subject: Re: RFR(S) 8208658: Make CDS archived heap regions usable
> >>> even if
> >>> compressed oop encoding has changed
> >>>
> >>> Thanks Thomas. I've fixed the comment, did more hs-tier1-3 testing to
> >>> validate the patch, and pushed.
> >>>
> >>> - Ioi
> >>>
> >>> On 8/22/18 1:32 AM, Thomas Schatzl wrote:
> >>>> Hi Ioi,
> >>>>
> >>>> On Tue, 2018-08-21 at 10:38 -0700, Ioi Lam wrote:
> >>>>> Hi Thomas.
> >>>>>
> >>>>> Thanks for the review. I've updated the webrev according to your
> >>>>> comments. See
> >>>>>
> >>>>> http://cr.openjdk.java.net/~iklam/jdk12/8208658-relocate-archived-
> hea
> >>>>> p-regions.v03.delta/
> >>>>>
> >>>>     looks good sans Jiangli's comment about that log message. I do not
> >>>> need to see a new webrev for that change either.
> >>>>
> >>>> Thanks,
> >>>>     Thomas
> >>>>
> >