RFR (S) 8245720: Shenandoah: improve configuration logging

[Roman Kennke]

Hi Aleksey,

On Tue, 2020-05-26 at 09:50 +0200, Aleksey Shipilev wrote:
> RFE:
>   https://bugs.openjdk.java.net/browse/JDK-8245720
> 
> As the follow up of JDK-8244817 for Shenandoah GC, it makes sense to
> enable Shenandoah to print
> similar info. Example output:
> 
> [0.006s][info][gc] Using Shenandoah
> [0.006s][info][gc] Heuristics ergonomically sets
> -XX:+ExplicitGCInvokesConcurrent
> [0.006s][info][gc] Heuristics ergonomically sets
> -XX:+ShenandoahImplicitGCInvokesConcurrent
> [0.360s][info][gc,init] Version: 15-internal+0-adhoc.shade.jdk-jdk
> (fastdebug)
> [0.360s][info][gc,init] CPUs: 16 total, 16 available
> [0.360s][info][gc,init] Memory: 125G
> [0.360s][info][gc,init] Large Page Support: Disabled
> [0.360s][info][gc,init] NUMA Support: Disabled
> [0.360s][info][gc,init] Compressed Oops: Enabled (Zero based)
> [0.360s][info][gc,init] Heap Min Capacity: 1G
> [0.360s][info][gc,init] Heap Initial Capacity: 1G
> [0.360s][info][gc,init] Heap Max Capacity: 10G
> [0.360s][info][gc,init] Pre-touch: Disabled
> [0.360s][info][gc,init] Mode: Snapshot-At-The-Beginning (SATB)
> [0.360s][info][gc,init] Heuristics: Adaptive
> [0.360s][info][gc,init] Heap Region Count: 2560
> [0.360s][info][gc,init] Heap Region Size: 4M
> [0.360s][info][gc,init] TLAB Size Max: 4M
> [0.360s][info][gc,init] Humongous Object Threshold: 4M
> [0.360s][info][gc,init] Reference Processing: Parallel discovery,
> Parallel processing
> [0.360s][info][gc,init] Parallel Workers: 8
> [0.360s][info][gc,init] Concurrent Workers: 4
> Ready
> 

I like this 'Ready', kinda retro thing as in:
https://www.c64-wiki.de/images/2/28/fehlermeldung_syntax.png


> I am thinking to just inline the upstream superclass InitLogger into
> ShenandoahInitLogger when
> backporting this to 11u and 8u.
> 
> Webrev:
>   https://cr.openjdk.java.net/~shade/8245720/webrev.01/
> 
> Testing: hotspot_gc_shenandoah
> 

Looks good!

Thanks,
Roman