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

[Per Liden]

On 08/29/2018 07:05 PM, Ioi Lam wrote:
> How about creating a general purpose WB API that can query for all the 
> SupportedGCs[] defined in src/hotspot/share/gc/shared/gcConfig.cpp?

FYI, such an API already exists, WB_IsGCSupported(), which is used by 
the GC.Z.isSupported() function that Goetz suggested.

cheers,
Per

> 
> 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
>>>>>
>>
>