Request for Review - 8152208: Summary for phase times are incorrect with and without UseDynamicNumberOfGCThreads

Jon Masamitsu jon.masamitsu at oracle.com
Mon Mar 21 21:55:06 UTC 2016


Bengt,

Thanks for the review.

On 03/21/2016 02:13 AM, Bengt Rutisson wrote:
>
> Hi Jon,
>
> On 2016-03-21 03:43, Jon Masamitsu wrote:
>> The averages reported for phase times (for example "Ext Root 
>> Scanning") were
>> incorrect.  Not all the per thread values were included in the sum 
>> and the
>> average value was incorrect (this with build 9-ea+1100)
>>
>> [0.366s][debug][gc,phases            ] GC(2)     Ext Root Scanning 
>> (ms):   Min:  0.3, Avg:  0.2, Max:  0.4, Diff:  0.0, Sum:  0.3
>> [0.366s][trace][gc,phases,task       ] 
>> GC(2)                                0.4  0.3
>>
>> With the fix all values are included in the sum and the average is 
>> correct.
>>
>> [2.830s][debug][gc,phases            ] GC(0)     Ext Root Scanning 
>> (ms):   Min:  5.7, Avg:  7.3, Max:  8.9, Diff:  3.1, Sum: 14.6
>> [2.830s][trace][gc,phases,task       ] 
>> GC(0)                                8.9  5.7
>>
>> https://bugs.openjdk.java.net/browse/JDK-8152208
>> http://cr.openjdk.java.net/~jmasa/8152208/webrev.00/
>
> Nice catch! Your change looks good.
>
> The method WorkerDataArray<T>::sum(uint active_threads) just above the 
> average() method has the same issue. Can you fix that too?

Yes, indeed.

I messed up the delta a bit so all the changes are in the 
workerDataArray.inline.hpp
webrev.  The test has not changed.

http://cr.openjdk.java.net/~jmasa/8152208/webrev.01/

Jon

>
> Thanks,
> Bengt
>
>>
>> Thanks.
>>
>> Jon
>

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