RFR(S): 8132720: Add tests which checks that Humongous objects are not moved after Full GC

[Kirill Zhaldybin]

Jon,

Thank you for reviewing the fix.

Here are a new WebRev:

http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8132720/webrev.03/

Could you please read comments inline?

Regards, Kirill

On 04.01.2016 23:00, Jon Masamitsu wrote:
> Kirill,
>
> Generally looks good.  Just some minor points.
>
> http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8132720/webrev.02/test/gc/g1/humongousObjects/TestHumongousMovement.java.html
>
>
> If you gave the parameter "allocation" a different name, could you
> avoid having to use the "this" in the constructor?  Also, is
> the "this" needed in isAddressChanged() and printDetails()?
>
>    62         public AllocationData(byte[] allocation) {
>    63             this.allocation = allocation;
>    64             this.objectAddress = new
> BigInteger(Long.toUnsignedString((WB.getObjectAddress(this.allocation))));
>    65         }
Fixed.

>
>
>
> Is it important to the test that some humongous objects are
> garbage collected?  You could get to this point
>
>   118         int toDelete = (int) (allocations.size() *
> HUMONGOUS_OBJECTS_DELETED_FACTOR);
>
>
> and only have allocated 1 humongous object so toDelete would be 0
> and  none of the humongous objects would be removed at
>
>   120         for (int i = 0; i < toDelete; ++i) {
Since Xmx, Xms and G1HeapRegionSize java options are specified and
regionsToAllocate = (int) (WB.g1NumFreeRegions() * 
ALLOCATED_HUMONGOUS_REGIONS_FACTOR);
where ALLOCATED_HUMONGOUS_REGIONS_FACTOR is equal 0.25 I don't think 
it's possible now.
Do you think it worth to add a sanity check for this case?

>
>
> Jon
>
> On 01/03/2016 03:34 PM, Kirill Zhaldbybin wrote:
>> Hi!
>>
>> Could you please review the following test?
>>
>> The test allocates humongous objects, deletes some of them, calls full
>> gc and checks that reachable humongous objects were not moved.
>>
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8132720
>>
>> Webrev:
>> http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8132720/webrev.02/
>>
>> Thank you.
>>
>> Regards, Kirill
>