Code review request: 7188594 Print statistic collected by NMT with VM flag

[Zhengyu Gu]

On 8/29/2012 10:34 PM, Vladimir Kozlov wrote:
> On 8/29/12 6:07 PM, Zhengyu Gu wrote:
>>
>>
>> On 8/29/2012 4:34 PM, Vladimir Kozlov wrote:
>>> You need to duplicate code in java.cpp in #else version of 
>>> print_statistics() since you can collect this date in
>>> product VM. And move warning message to arguments.cpp (and switch 
>>> off flag if NMT is off):
>>> if (!MemTracker::is_on() && PrintNMTStatistics) {
>>> warning(err_msg("Native memory tracking is off due to ", 
>>> MemTracker::reason()));
>>> PrintNMTStatistics = false;
>>> }
>> NMT can be shutdown during VM execution, through jcmd or by NMT 
>> runtime itself in some extreme scenarios, such as
>> running out of native memory, etc. so the checking in argument 
>> parsing phase is not sufficient.
>
> Do NMT throw out already collected data (free memory used by data) if 
> it is shutdown this way? If a data still there you can print it even 
> when NMT is off when VM exit.
It does throw out all data and free memory it used.

-Zhengyu


>
> Vladimir
>
>>
>> -Zhengyu
>>
>>>
>>> Vladimir
>>>
>>> Vladimir Kozlov wrote:
>>>> Hi, Zhengyu
>>>>
>>>> Could you give an example of output? I thought you need more 
>>>> changes for this.
>>>>
>>>> thanks,
>>>> Vladimir
>>>>
>>>> Zhengyu Gu wrote:
>>>>> This is a simple RFE, that allows VM to dump collected native memory
>>>>>
>>>>> tracking data before exits.
>>>>>
>>>>> CR: http://bugs.sun.com/view_bug.do?bug_id=7188594
>>>>> Webrev: http://cr.openjdk.java.net/~zgu/7188594/webrev.00/
>>>>>
>>>>> Thanks,
>>>>>
>>>>> -Zhengyu
>>>>>