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

[David Holmes]

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.
>>
>> 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
>