RFR (XS) 8152957: Improve specificity of safepoint logging to print safepoint typ

coleen.phillimore at oracle.com coleen.phillimore at oracle.com
Tue Dec 19 22:32:13 UTC 2017



On 12/19/17 5:31 PM, David Holmes wrote:
> On 20/12/2017 8:18 AM, coleen.phillimore at oracle.com wrote:
>> On 12/19/17 5:14 PM, David Holmes wrote:
>>> On 20/12/2017 8:07 AM, coleen.phillimore at oracle.com wrote:
>>>> On 12/19/17 5:05 PM, David Holmes wrote:
>>>>> Hi Coleen,
>>>>>
>>>>> On 20/12/2017 6:12 AM, coleen.phillimore at oracle.com wrote:
>>>>>> Summary: upgrade safepoint begin logs to Info logging, which has 
>>>>>> the reason.
>>>>>
>>>>> 410   log_info(safepoint)("Entering safepoint region: %s", 
>>>>> VMThread::vm_safepoint_description());
>>>>> 497/504       log_debug(safepoint)("Leaving safepoint region");
>>>>>
>>>>> You need to change the "leaving" part to info as well.
>>>>
>>>> I had that but it seems like extra not interestesting info. The 
>>>> safepoint stopped time is more useful and that's when we've left 
>>>> the safepoint region.
>>>
>>> Seems unbalanced to me. And it's not clear from where the "safepoint 
>>> stopped time" actually gets printed.
>>
>> If you think it's helpful then I'll add it.  It comes from this line 
>> closer to the end of the function.
>>
>>        RuntimeService::record_safepoint_end();
>
> I'd prefer it.

You got it.
Thanks,
Coleen
>
> Thanks,
> David
>
>> thanks,
>> Coleen
>>
>>>>>
>>>>> Though I'm not clear how this simple change relates to the bug 
>>>>> synopsis and the request to "print safepoint type" ??
>>>>
>>>> The VMThread::vm_safepoint_description() says why we safepoint. 
>>>> Which is RevokeBias most of the time.
>>>
>>> Ah! Right.
>>>
>>> Thanks,
>>> David
>>>
>>>> thanks
>>>> Coleen
>>>>>
>>>>> Thanks,
>>>>> David
>>>>>
>>>>>> See bug for sample.
>>>>>>
>>>>>> Tested with existing jtreg tests to make sure new logging line 
>>>>>> doesn't break anything.
>>>>>>
>>>>>> open webrev at http://cr.openjdk.java.net/~coleenp/8152957.01/webrev
>>>>>> bug link https://bugs.openjdk.java.net/browse/JDK-8152957
>>>>>>
>>>>>> Thanks,
>>>>>> Coleen
>>>>
>>



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