RFR (S): 8244815: Always log MMU information in G1

Thomas Schatzl thomas.schatzl at oracle.com
Tue May 12 13:53:09 UTC 2020

Hi all,

   can I have reviews for this change that adds MMU logging for all 
pauses, not only when it is violated?

This makes the logging similar to JFR events which are posted always too.

Ie. currently G1 prints

[95.616s][info ][gc,mmu        ] GC(2932) MMU target violated: 10.5ms 

at info level if G1 did not keep MMU goals in the last pause.

This change adds the message

[82.315s][debug][gc,mmu        ] GC(2598) MMU target: 7.3ms (10.0ms/11.0ms)

at debug level even when MMU is kept. This helps with analyzing current MMU.

There is some a bit ugly code to select the correct message level. Maybe 
there is a better way. An alternative would be to move the message to 
debug level always?

hs-tier1-3, eyeballing local logs


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