[RFR] 8043766: CMM Testing: 8u40 Decommit auxiliary data structures

[Andrey Zakharov]

On 26.09.2014 14:47, Thomas Schatzl wrote:
> G1ConcRSLogCacheSize of 10 does not require that much memory (and in
> fact is default) so that you need to worry about its maximum size.
>> I'm worried about 2^23 - 2^30 caches size which can brings massive
>> swapping and timeouts of tests
> Then I suggest just removing the ...Data25/Data30, even ...Data20,
> tests. There is not much difference in behavior from a GC point of view
> between these heap sizes. The values are simply used to size that data
> structure.
>>> - fixing G1ConcRSLogCacheSize would also remove the need to calculate
>>> some maximum value for G1ConcRSLogCacheSize. GetMaxCacheSize()
>>> calculates the maximum G1ConcRSLogCacheSize based on the free java heap.
>>> However, the data structure is allocated on the C heap, there is no real
>>> connection between free java heap and free C heap anyway.
>> Could please, suggest something here?
>> I'm just judging about available memory by available heap memory.
>> Thanks.
> Available Java heap memory (Runtime.freeMemory() returns the available
> memory on the Java heap), not available C heap memory. One has no direct
> connection to the other.
>
> By simply removing the tests with the large G1ConcRSLogCacheSize values,
> which imo do not add a lot, you do not need such a contrived check.
As we have this feature in product - there needs to be tested.
> Thanks,
>    Thomas
>
>