RFR(T): 8239503: FieldLayout/OldLayoutCheck.java fails due to "RuntimeException: Misplaced int field: expected 24 to equal 12"

[Daniel D. Daugherty]

On 2/20/20 6:11 PM, David Holmes wrote:
> On 21/02/2020 9:03 am, Daniel D. Daugherty wrote:
>> On 2/20/20 6:02 PM, David Holmes wrote:
>>> On 21/02/2020 6:38 am, Daniel D. Daugherty wrote:
>>>> Greetings,
>>>>
>>>> We have a Tier3 failure that's causing a bit of noise in the CI.
>>>>
>>>> Per has determined that the test in question should not run with ZGC
>>>
>>> This seems a temporary workaround. Obviously there are issues with 
>>> the new field layout code and interaction with ZGC that have not 
>>> been accounted for. The underlying problem presumably needs to be 
>>> addressed and now we won't have an open bug for that. I would have 
>>> treated this like a "problem listing" and created a sub-task.
>>
>> This is what Per wrote in his comment before his proposed patch:
>>
>>> Using -XX:+UseCompressedClassPointers has no effect when using ZGC, 
>>> so the field offset will be different. The test should just exclude 
>>> ZGC. 
>>
>> That doesn't sound like a temporary condition with ZGC to me.
>
> Apologies I should have dug deeper first.

No problem. I'll add you as a second reviewer. My Tier3 is stalled
right now. Hasn't made much progress in a while...

Dan


>
> David
>
>> Dan
>>
>>
>>>
>>> Cheers,
>>> David
>>> -----
>>>
>>>> and added a patch to the bug report. I'm testing that patch with a
>>>> Tier3 test run right now...
>>>>
>>>> Here's what it looks like:
>>>>
>>>> $ hg diff
>>>> diff -r 38fc3785784a 
>>>> test/hotspot/jtreg/runtime/FieldLayout/OldLayoutCheck.java
>>>> --- a/test/hotspot/jtreg/runtime/FieldLayout/OldLayoutCheck.java 
>>>> Thu Feb 20 20:04:15 2020 +0000
>>>> +++ b/test/hotspot/jtreg/runtime/FieldLayout/OldLayoutCheck.java 
>>>> Thu Feb 20 15:20:47 2020 -0500
>>>> @@ -28,7 +28,7 @@
>>>>    * @library /test/lib
>>>>    * @modules java.base/jdk.internal.misc
>>>>    *          java.management
>>>> - * @requires vm.bits == "64"
>>>> + * @requires vm.bits == "64" & vm.gc != "Z"
>>>>    * @run main/othervm -XX:+UseCompressedClassPointers 
>>>> -XX:-UseEmptySlotsInSupers OldLayoutCheck
>>>>    */
>>>>
>>>>
>>>> Thanks, in advance, for any comments, questions or suggestions.
>>>>
>>>> Dan
>>>>
>>