RFR (S): 8012086: The object count event should only send events for instances occupying more than 0.5% of the heap

[Jesper Wilhelmsson]

Erik Helin skrev 8/5/13 1:00 PM:
> Jesper,
>
> On 05/08/2013 10:20 AM, Jesper Wilhelmsson wrote:
>> Erik Helin skrev 8/5/13 10:00 AM:
>>> Jesper,
>>>
>>> On 05/07/2013 09:52 PM, Jesper Wilhelmsson wrote:
>>>> Erik Helin skrev 7/5/13 9:28 PM:
>>>>> Jesper,
>>>>>
>>>>> I've changed the flag to be an experimental flag instead of a product
>>>>> flag.
>>>>
>>>> Thanks!
>>>>
>>>>> Please see new webrev at:
>>>>> http://cr.openjdk.java.net/~ehelin/8012086/webrev.02/
>>>>
>>>> If you want to change the description of the flag to say "... to
>>>> generate a trace event.", I think it would read better. But either way
>>>> I'm fine with this change.
>>>
>>> I think that an even better description would be "... to generate a
>>> possible
>>> trace event", since even if the instances of the class takes up more than
>>> ObjectCountCutOffPercent of the used heap, there is no guarantee that
>>> an event
>>> will be sent (the event might be turned off).
>>>
>>> What do you think?
>>
>> I think that the fact that the event might be turned off is unrelated to
>> this flag and that the description would look better without the
>> "possible".
>
> Ok sure, I will remove "possible" before pushing the change :)
>
> All good?

Yes, ship it! :-)

Thanks for fixing this!
/Jesper


>
> Thanks,
> Erik
>
>> /Jesper
>>
>>>
>>> Thanks,
>>> Erik
>>>
>>>> /Jesper
>>>>
>>>>
>>>>>
>>>>> Thanks,
>>>>> Erik
>>>>>
>>>>> On 05/07/2013 03:54 PM, Jesper Wilhelmsson wrote:
>>>>>> Hi,
>>>>>>
>>>>>> Please check with the serviceability team (CC:ed) before adding a flag
>>>>>> to control the threshold. I suspect that they would prefer some
>>>>>> tracing
>>>>>> specific way to configure these thresholds.
>>>>>> /Jesper
>>>>>>
>>>>>>
>>>>>> Erik Helin skrev 7/5/13 2:58 PM:
>>>>>>> Hi Bengt,
>>>>>>>
>>>>>>> thanks for the review!
>>>>>>>
>>>>>>> On 05/07/2013 11:42 AM, Bengt Rutisson wrote:
>>>>>>>>
>>>>>>>> Hi Erik,
>>>>>>>>
>>>>>>>> Looks good.
>>>>>>>>
>>>>>>>> Two minor nits:
>>>>>>>>
>>>>>>>> Could we make 0.05 into a flag or at least a declared constant?
>>>>>>>
>>>>>>> Good suggestion, I've turned into a flag: ObjectCountCutOffPercent.
>>>>>>>
>>>>>>> On 05/07/2013 11:42 AM, Bengt Rutisson wrote:
>>>>>>>> Could we rename _used_heap_in_words to something like
>>>>>>>> _total_size_in_words or _base_size_in_words since it is not
>>>>>>>> really the
>>>>>>>> used count for the heap?
>>>>>>>
>>>>>>> Agree, I renamed it to _total_size_in_words.
>>>>>>>
>>>>>>> Please see new webrev at:
>>>>>>> http://cr.openjdk.java.net/~ehelin/8012086/webrev.01/
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Erik
>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Bengt
>>>>>>>>
>>>>>>>> On 5/7/13 10:14 AM, Erik Helin wrote:
>>>>>>>>> Hi all,
>>>>>>>>>
>>>>>>>>> this change makes sure that we only send the trace event
>>>>>>>>> vm/gc/detailed/object_count_after_gc if the total size of all the
>>>>>>>>> instances of a class occupies more than 0.5% of the used heap.
>>>>>>>>>
>>>>>>>>> Webrev:
>>>>>>>>> http://cr.openjdk.java.net/~ehelin/8012086/webrev.00/
>>>>>>>>>
>>>>>>>>> Testing:
>>>>>>>>> JPRT
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Erik
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>
>>>
>