RFR: 8170737: Not enough old space utilisation

Dmitry Fazunenko dmitry.fazunenko at oracle.com
Fri Jan 13 16:55:11 UTC 2017

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?


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

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