RFR: 8028787: tmtools/jstat/gcoldcapacity/jstat_gcoldcapacity02 fails nsk.share.Failure: OGC < OGCMN in RT_Baseline

Stefan Johansson stefan.johansson at oracle.com
Tue Aug 26 14:14:35 UTC 2014

Thanks Thomas and Stefan for reviewing.

Just an update about testing, after some good input from Bengt I managed 
to reproduce with the tmtools-test in question and also verify that the 
fix works as intended with the test.


On 2014-08-26 12:05, Stefan Karlsson wrote:
> On 26/08/14 11:46, Stefan Johansson wrote:
>> Hi,
>> Please review this fix for:
>> https://bugs.openjdk.java.net/browse/JDK-8028787
>> Webrev:
>> http://cr.openjdk.java.net/~sjohanss/8028787/webrev.00
> Looks good. Thanks for fixing this!
> StefanK
>> Summary:
>> When setting up the counters used by jstat for determining the min 
>> and max size of the generations we currently do not use the collector 
>> policy to get these values. Instead the underlying space has been 
>> used, and that do not have any notion of a minimum. Changing to use 
>> the collector policy will avoid the problems we are seeing where the 
>> current capacity is smaller than the minimum. This was previously 
>> possible if a generation was resized to something smaller than the 
>> initial size (which was setup as minimum for the counter).
>> Testing:
>> I did not manage to reproduce the failure with the test in question 
>> on my machine but I was able to manually construct the same symptoms 
>> (getting a smaller OGC than OGCMN) using the default collector and 
>> with this fix they are gone.
>> Thanks,
>> StefanJ

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