RFR: Do not reset learning cycles after resizing

[Kelvin Nilsen]

On Tue, 17 Jan 2023 19:35:40 GMT, William Kemper <wkemper at openjdk.org> wrote:

> Also, require more than 10 gc cycles before trigger can resize generations. The behavior on the extremem 'phased' workload looks much better:
> 
> [1334.381s][info][gc,stats       ]    66 Successful Concurrent GCs
> [1334.381s][info][gc,stats       ]       0 invoked explicitly
> [1334.381s][info][gc,stats       ]       0 invoked implicitly
> [1334.381s][info][gc,stats       ] 
> [1334.381s][info][gc,stats       ]     7 Completed Old GCs
> [1334.381s][info][gc,stats       ]       0 mixed
> [1334.381s][info][gc,stats       ]       0 interruptions
> [1334.381s][info][gc,stats       ] 
> [1334.381s][info][gc,stats       ]     1 Degenerated GCs
> [1334.381s][info][gc,stats       ]       1 caused by allocation failure
> [1334.381s][info][gc,stats       ]         1 happened at Mark
> [1334.381s][info][gc,stats       ]       1 upgraded to Full GC
> [1334.381s][info][gc,stats       ] 
> [1334.381s][info][gc,stats       ]     0 Abbreviated GCs
> [1334.381s][info][gc,stats       ] 
> [1334.381s][info][gc,stats       ]     1 Full GCs
> [1334.381s][info][gc,stats       ]       0 invoked explicitly
> [1334.381s][info][gc,stats       ]       0 invoked implicitly
> [1334.381s][info][gc,stats       ]       0 caused by allocation failure
> [1334.381s][info][gc,stats       ]       1 upgraded from Degenerated GC
> 
> The full cycle here was the first cycle after the last of the initial learning cycles.

Thanks.  This looks like a very good improvement.

(I assume we are separately looking into the case where the MMU triggers cause young to expand even when a more enlightened perspective would instead expand OLD.)

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Marked as reviewed by kdnilsen (Committer).

PR: https://git.openjdk.org/shenandoah/pull/203