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

[Yumin Qi]

Sorry the last sentence is not right: The test went through but due to 
the other bug https://bugs.openjdk.java.net/browse/JDK-8240698

The options are not consistent for dump/run this caused CDS was disabled 
for the run. This led this test failed to find _nofast_aload0.

Yumin

On 3/10/20 8:26 AM, Yumin Qi wrote:
> 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
>>>>
>>