[13] RFR(xs) 8226462: [TESTBUG] runtime/appcds/sharedStrings/SysDictCrash.java failed with Cannot dump shared archive

[David Holmes]

Hi Calvin,

On 23/06/2019 10:50 pm, Calvin Cheung wrote:
> Hi David,
> 
> Thanks for your review!
> 
> I've a different fix by issuing a warning message from the VM and have 
> the dump time part of the test to look for that warning message in case 
> there's a RuntimeException. If there's such warning, don't continue 
> further.
> 
> Here's an updated webrev:
>      http://cr.openjdk.java.net/~ccheung/8226462/webrev.01/
> 
> Warning message looks like the following:
> 
> Java HotSpot(TM) 64-Bit Server VM warning: UseCompressedOops and 
> UseCompressedClassPointers have been disabled due to max heap 
> 33768409088 > compressed oop heap 32178700288
> Java HotSpot(TM) 64-Bit Server VM warning: Please check the setting of 
> MaxRAMPercentage 12.50

If a warning is needed I think this should be a single warning, not two.

But I'm concerned that this warning may be triggered unexpectedly in 
some of our test runs and that other tests won't be prepared for this 
warning to appear.

David
-----

> thanks,
> Calvin
> 
> On 6/21/19, 6:00 PM, David Holmes wrote:
>> Hi Calvin,
>>
>> On 21/06/2019 3:16 pm, Calvin Cheung wrote:
>>> bug: https://bugs.openjdk.java.net/browse/JDK-8226462
>>>
>>> webrev: http://cr.openjdk.java.net/~ccheung/8226462/webrev.00/
>>>
>>> On a test host with large amount of RAM, the UseCompressedOops and 
>>> the UseCompressedClassPointers flags would be disabled ergonomically 
>>> by the VM with the MaxRAMPercentage set to 12.5. To void the test 
>>> failure, the test has been changed to check the given 
>>> MaxRAMPercentage and uses it if the setting is <= 12.5.
>>
>> But if it fails on 12.5 presently then you would need to be < 12.5 
>> surely?
>>
>> And it's not the 12.5 per-se that is the issue IIUC but the amount of 
>> memory that 12.5% of RAM represents. If there is more memory you would 
>> need to use a smaller % to ensure it works - no?
>>
>> Thanks,
>> David
>> -----
>>
>>> Ran the test 20 times on the linux test host where the failure was 
>>> reproduced.
>>>
>>> thanks,
>>> Calvin