RFR: 8231296: ZGC: vmTestbase/nsk/jvmti/Allocate/alloc001/ fails

[Per Liden]

Hi Igor,

On 9/27/19 3:49 AM, Igor Ignatev wrote:
> Hi Per,
> 
>> On Sep 26, 2019, at 2:32 PM, Per Liden <per.liden at oracle.com> wrote:
>>
>> Hi Igor,
>>
>> I don't think it belongs in the problem list, for two reasons:
>>
>> 1) The test doesn't fail because of a bug. It fails because ZGC doesn't currently support that use case. In other words, the test shouldn't be testing something that isn't supposed to work.
> Problem lists aren’t only to exclude tests which fail due to bugs, they can be and are used for use cases you described as well.
>>
>> 2) As far as I know, the test in question is part of rt-tiers, where it's executed with the default GC (G1). So, the problem is typically only visible when doing non-CI testing with ZGC enabled.
> I agree that necessity to pass extra make arts whenever you are doing adhoc testing, esp. on a localhost, is cumbersome, but you are expected to do that anyway as some of tests are known to fail only w/ zGC and are in ProblemList-zgc.txt.
> 
> The main advantage of problem list over @requiers is semi-automatic reminding to re-enable tests when a defect is fixed/feature is implemented, it also sends a clear message that we plan to make a test pass.
> 
> In compiler, we 1st use @requiers to temporary exclude tests from graal testing, but soon we realized that there are two different meanings:1) test isn't able to pass w/ graal and will never be able to and 2) test can’t pass w/ graal now (b/c of test / product bugs and/or some features aren’t there), but we want to fix product/test and reenable test. we now try to use @requiers for 1 and problem list for 2, so the reasons and expectations are clearer, but there are still some tests which have @requiers which actually should be in problem list, and it’s expensive to go thru all of them to dig out which it should be. So I just don’t want you guys to get the same problems we got.

Ok, thanks. I think I see the problem list more of a temporary measure 
to avoid noise in the CI pipeline, i.e. when the test should work but 
doesn't. In cases where a test isn't expected to work, I think @requires 
is better. However, I do see your point, it's not always a black or 
white call.

cheers,
Per

>>
>> cheers,
>> Per
>>
>>> On 9/26/19 10:58 PM, Igor Ignatyev wrote:
>>> Hi Per,
>>> wouldn't it be better to put this test into zgc-specific problem list (test/hotspot/jtreg/ProblemList-zgc.txt)?
>>> Thanks,
>>> -- Igor
>>>>> On Sep 26, 2019, at 1:39 PM, Per Liden <per.liden at oracle.com> wrote:
>>>>
>>>> Please review this one-liner to disable vmTestbase/nsk/jvmti/Allocate/alloc001 when using ZGC. The root problem is that ZGC doesn't properly respect address space limitations (RLIMIT_AS). This test will be re-enabled again as part of fixing https://bugs.openjdk.java.net/browse/JDK-8231552
>>>>
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8231296
>>>> Webrev: http://cr.openjdk.java.net/~pliden/8231296/webrev.0
>>>>
>>>> /Per
>