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

[Erik Helin]

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?

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
>>>>>>>
>>>>>>>
>>>>>>
>>>>
>>