RFR: 8170737: Not enough old space utilisation

[Michail Chernov]

Hi,

I updated the webrev according to offline coments from Dmitry Fazunenko.
GarbageProducerTestBase was renamed to GarbageProducerTest. 
GcCauseTest02 and GcTest02 now uses GarbageProducerTest directly without 
inheritance.

http://cr.openjdk.java.net/~mchernov/8170737/webrev.02_to_01/
http://cr.openjdk.java.net/~mchernov/8170737/webrev.02/

Thanks,
Michail

On 24/01/2017 17:52, Michail Chernov wrote:
> Hi Dima,
>
> Thanks for your response.
>
> Updated webrev:
> http://cr.openjdk.java.net/~mchernov/8170737/webrev.01/
>
> Tests were refactored.
> There were several problems:
> 1. Checking of jstat output consistency should not be performed during 
> GC cycles because it can cause to additional failures. There is 
> checking in GarbageProducerTestBase.java that during jstat execution 
> were not any GC cycles. Jstat gets performance counters values 
> sequentially, so GC cycles should be avoided.
> 2. New gen size should be limited, because there can be OOME while 
> eating 70% of heap on some configurations.
> 3. Tests failed to get expected old gen occupancy because background 
> VM activity can change real occupancy. Now tests check real heap 
> occupancy (using MXBean) and compares it with jstat output.
>
> The testing is in progress.
>
> Thanks,
> Michail
>
> On 13/01/2017 19:55, Dmitry Fazunenko wrote:
>> Hi Michail,
>>
>> GarbageProducer tries to predict at the beginning how many objects to 
>> allocate later to achieve target memory usage percent.
>> This way doesn't look like a good idea:
>> - objects created by libraries (during initialization) may not be 
>> collected yet
>> - eatMetaspace() besides allocating metaspace consumes some heap 
>> space, but this amount is not taken into account.
>>
>> Will it make sense to use MXBean for heap as well as for metaspace?
>>
>> Thanks,
>> Dima
>>
>> ps: one more nit: "GarbageProducer{" - please insert a space.
>>
>> On 13.01.2017 14:56, Michail Chernov wrote:
>>> Hi,
>>>
>>> Could I have a reviews for this change, please?
>>>
>>> http://cr.openjdk.java.net/~mchernov/8170737/webrev.00/
>>> https://bugs.openjdk.java.net/browse/JDK-8170737
>>>
>>> Test fails because Runtime.maxMemory() results depends on the heap 
>>> size shrinking. So need to calculate the expected heap occupation 
>>> before a garbage allocation. Tests were updated accordingly. Also 
>>> GcProvokerImpl.java was removed because it was not removed on 
>>> previous commit by mistake.
>>> Tested via RBT.
>>>
>>> Thanks,
>>> Michail
>>
>>
>
>