RFR (S) 8210724: Change the verbosity threshold of logging for [oopstorage,ref]

[Kim Barrett]

> On Sep 13, 2018, at 8:01 PM, Man Cao <manc at google.com> wrote:
> 
> Hi all,
> 
> Could anyone review this logging change for oopstorage?
> Webrev: http://cr.openjdk.java.net/~jcbeyler/8210724/webrev.00/
> Bug: https://bugs.openjdk.java.net/browse/JDK-8210724
> 
> This is similar to the webrev I previously sent for https://bugs.openjdk.java.net/browse/JDK-8210562. Kim mentioned it might be reasonable to improve the logging in oopStorage.cpp. We discussed and decided to create a separate issue for improving the logging.
> 
> The patch changes the logging level for [oopstorage,ref] to trace, and consistently uses debug level for [oopstorage,blocks] and unusual events, and uses log_info() for printing statistics. I think this would make the logging for oopstorage more user-friendly.
> 
> Below is comparison of lines of messages:
> $ java -Xlog:oopstorage*=<level> -Xms500m -Xmx500m -jar dacapo-9.12-bach.jar tradesoap
>                 info   | debug  | trace 
> without patch:  107934 | 112990 | 112701
> with patch:       1694 |   5247 | 112241
> 
> -Man

Looks good.