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

[David Holmes]

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.

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
>>>
>