RFR: 8224112: [TESTBUG] java/util/Base64/TestEncodingDecodingLength.java should be skipped with insufficient memory

[Jie Fu]

Hi Alan,

Oh, we just have 2G swap buffer on our machine.
Yes, we do have observed some other intermittent failures due to 
memory/network/GUI reasons, but this case is the most frequently 
observed one.
I just try to improve the test stability since it seems impossible to 
always keep others away from the machine when doing the tests.

Thanks.
Best regards,
Jie

On 2019/5/18 下午4:25, Alan Bateman wrote:
> On 18/05/2019 02:17, Jie Fu wrote:
>> Hi Alan,
>>
>> On 2019/5/17 下午11:00, Alan Bateman wrote:
>>> The issue isn't clear. The test only runs when on 64-bit systems 
>>> with >= 10GB memory. Is the issue related to the -concurrency 
>>> setting that you specify to jtreg?
>> No. Even we set the concurrency=1, the issue may still occur.
>> os.maxMemory >= 10g just check whether the capacity of physical 
>> memory is >= 10g, not the available memory to be used.
>>
>> Our test machine has only 16GB physical memory and is shared by many 
>> people in our group.
>> The test seems to fail occasionally especially when the test machine 
>> is busy.
>> I'm trying to find a better solution to this problem.
> I'm guessing this must be an embedded system with no swap configured. 
> If so then I don't think this is solvable without reserving the 
> machine when you need to run tests. This test uses 6-8GB of memory and 
> there are several other tests that consume lots of memory too. If 
> several people are trying to run tests or do builds at the same time 
> then I assume you'll have issues in many areas. I see your patch to 
> have the test skip when there isn't 6GB of "free memory" but I assume 
> you'll still have intermittent failures when someone else tries to run 
> resource hungry tests at around the same time.
>
> -Alan