RFR(XS): 8240691: serviceability/sa/ClhsdbCDSJstackPrintAll.java and serviceability/sa/ClhsdbCDSCore.java not work with ZGC

[Yumin Qi]

Hi, Chris


     The original failure is caused by fixing bug 
https://bugs.openjdk.java.net/browse/JDK-8240563

    The removal of checking UseCompressedOops and 
UseCompressedClassPointers since CDS now is working with them on/off.

    The testing will be skipped ZGC since the old code detecting CDS on 
64 bit is checking if those two flags turned off --- CDS only works with 
compressed oops before (https://bugs.openjdk.java.net/browse/JDK-8232069 
pushed. With ZGC, those two flags will be turned off so the detection of 
CDS will return false. This makes the tests skipped, it will never 
tested with ZGC. Now the detection will return true if built with CDS 
enabled. So the test will go through with CDS. Unfortunately sa does not 
work with ZGC heap I think so it failed.

    Thanks

    Yumin

On 3/9/20 9:33 PM, Chris Plummer wrote:
> Hi Yumin,
>
> While your fix is a more bullet proof way of checking if CDS is on, 
> what was broken with the original version (was there a stray "false" 
> in the output"), and what does this have to do with ZGC?
>
> thanks,
>
> Chris
>
> On 3/9/20 8:06 PM, Yumin Qi wrote:
>>
>> Hi,
>>
>>     I made a change after discussed with Ioi, the test should check 
>> against UseSharedSpaces instead, it passed with/without change of 
>> 8240563 (tested in local). Also passed tier1,2,3.
>>
>>      URL: http://cr.openjdk.java.net/~minqi/8240691/webrev/
>>
>>
>>     Thanks
>>
>>      Yumin
>>
>>
>> On 3/6/20 2:26 PM, Yumin Qi wrote:
>>> HI,
>>>
>>>   Can I have your reviews on
>>>
>>>   Bug: https://bugs.openjdk.java.net/browse/JDK-8240691
>>>
>>>   webrev: http://cr.openjdk.java.net/~minqi/8240691/webrev/
>>>
>>>   Summary: With JDK-8232069 
>>> (https://bugs.openjdk.java.net/browse/JDK-8232069), CDS works with 
>>> UseCompressedOop and UseCompressedClassPointers off. The code for 
>>> detecting CDS will report false with ZGC since ZGC turned off those 
>>> two flags. The detection code will be changed in 
>>> JDK-8240563(https://bugs.openjdk.java.net/browse/JDK-8240563), this 
>>> will cause those two tests fail.
>>>
>>>
>>>    Tests: jtreg to show the tests not selected with ZGC.
>>>
>>>    Thanks
>>>
>>>    Yumin
>>>
>