Integrated: 8364081: Shenandoah & GenShen logging improvement

[Rui Li]

On Fri, 25 Jul 2025 01:30:59 GMT, Rui Li <duke at openjdk.org> wrote:

> Fix missing `increment_total_collections` usages in Shenandoah (otherwise, the invocation count is always 0 as shown in https://github.com/openjdk/jdk/pull/26272 overview). 
> 
> Also added some generational information for generational shenandoah logging.
> 
> Shenandoah logging samples:
> 
> 
> ######################
> Shenandoah - Before GC
> ######################
> [0.161s][debug][gc,heap      ] GC(0) Heap Before GC invocations=0 (full 0):
> [0.161s][debug][gc,heap      ] GC(0)  Shenandoah Heap
> [0.161s][debug][gc,heap      ] GC(0)    100M max, 100M soft max, 100M committed, 40312K used
> [0.161s][debug][gc,heap      ] GC(0)   400 x 256K regions
> [0.161s][debug][gc,heap      ] GC(0)  Status: not cancelled
> [0.161s][debug][gc,heap      ] GC(0)  Reserved region:
> [0.161s][debug][gc,heap      ] GC(0)   - [0x00000000f9c00000, 0x0000000100000000) 
> [0.161s][debug][gc,heap      ] GC(0)  Collection set:
> [0.161s][debug][gc,heap      ] GC(0)   - map (vanilla): 0x0000000000004e70
> [0.161s][debug][gc,heap      ] GC(0)   - map (biased):  0x0000000000001000
> [0.161s][debug][gc,heap      ] GC(0) 
> [0.161s][debug][gc,metaspace ] GC(0) Metaspace Before GC invocations=0 (full 0):
> [0.161s][debug][gc,metaspace ] GC(0)  Metaspace       used 86K, committed 320K, reserved 1114112K
> [0.161s][debug][gc,metaspace ] GC(0)   class space    used 3K, committed 128K, reserved 1048576K
> 
> ######################
> Shenandoah - After GC
> ######################
> [2.179s][debug][gc,heap        ] GC(9) Heap After GC invocations=17 (full 7):
> [2.179s][debug][gc,heap        ] GC(9)  Shenandoah Heap
> [2.179s][debug][gc,heap        ] GC(9)    100M max, 100M soft max, 100M committed, 97113K used
> [2.179s][debug][gc,heap        ] GC(9)   400 x 256K regions
> [2.179s][debug][gc,heap        ] GC(9)  Status: not cancelled
> [2.179s][debug][gc,heap        ] GC(9)  Reserved region:
> [2.179s][debug][gc,heap        ] GC(9)   - [0x00000000f9c00000, 0x0000000100000000) 
> [2.179s][debug][gc,heap        ] GC(9)  Collection set:
> [2.179s][debug][gc,heap        ] GC(9)   - map (vanilla): 0x0000000000004e70
> [2.179s][debug][gc,heap        ] GC(9)   - map (biased):  0x0000000000001000
> [2.179s][debug][gc,heap        ] GC(9) 
> [2.179s][debug][gc,metaspace   ] GC(9) Metaspace After GC invocations=17 (full 7):
> [2.179s][debug][gc,metaspace   ] GC(9)  Metaspace       used 125K, committed 320K, reserved 1114112K
> [2.179s][debug][gc,metaspace   ] GC(9)   class space    used 4K, committed 128K, reserved 1048576K
> 
> 
> Generational Shenandoah logging samples
> 
> ############...

This pull request has now been integrated.

Changeset: 3e4e5dd0
Author:    Rui Li <ruiamzn at amazon.com>
Committer: William Kemper <wkemper at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/3e4e5dd06f8a74ada792e5d03b4604adcf618a4a
Stats:     39 lines in 4 files changed: 27 ins; 0 del; 12 mod

8364081: Shenandoah & GenShen logging improvement

Reviewed-by: ysr, wkemper

-------------

PR: https://git.openjdk.org/jdk/pull/26469