RFR: 8041946 - CMM Testing: 8u40 an allocated humongous object at the end of the heap should not prevents shrinking the heap

Jesper Wilhelmsson jesper.wilhelmsson at oracle.com
Wed Jun 11 13:19:49 UTC 2014

Hi Andrey,

As it is used, the constant MINIMAL_HEAP_SIZE does not define the minimal heap 
size but the minimal young gen size. Would you consider calling it 

Besides that it looks ok.

Andrey Zakharov skrev 9/6/14 16:31:
> Hi, everyone!
> Please, review this test for new feature in G1 - sorted free list which make
> possible shrinking of the defragmented heap.
> To proper testing of free list sorting we need to defragment memory with small
> young and humongous objects.
> This is test scenario:
>   - make enough space for new objects to prevent it going old.
>   - allocate bunch of small objects, and a bit of humongous several times
> (ssssHssssHssssHssssHssssHssssHssssHssssH)
>   - free almost all of allocated stuff. Check that heap shrinks after GC.
> (-----------H)
> Webrev: http://cr.openjdk.java.net/~fzhinkin/azakharov/8041946/webrev.00/
> Bug: https://bugs.openjdk.java.net/browse/JDK-8041946
> I have tested it along all major platforms and it works fine. There is lag on
> Solaris MXBeans about memory usage, so I need sleep by 1s.
> It will be very nicely if somebody advice me about method which "flush" memory
> usage info to remove this sleep.
> Thanks.

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