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

[coleen.phillimore at oracle.com]

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.
>
> 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.

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