RFR: 8329223: Parallel: Parallel GC resizes heap even has -Xms = -Xmx [v7]

[Albert Mingkun Yang]

On Sun, 21 Apr 2024 00:17:40 GMT, Zhengyu Gu <zgu at openjdk.org> wrote:

>> Parallel GC resizes old gen even when setting -Xms == -Xmx. 
>> 
>> During GC argument setup, it always set `MinOldSize = GenAlignment` and does not make any adjustment when `-Xms == -Xmx`, while does the adjustment for young gen [here](https://github.com/openjdk/jdk/blob/master/src/hotspot/share/gc/shared/genArguments.cpp#L250)
>
> Zhengyu Gu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update copyright

src/hotspot/share/gc/shared/genArguments.cpp line 311:

> 309:     } else if (initial_old_size < MinOldSize) {
> 310:       log_warning(gc, ergo)("Inconsistency between initial old size and minimum old size");
> 311:       MinOldSize = initial_old_size;

Should this be `initial_old_size = MinOldSize;`?

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PR Review Comment: https://git.openjdk.org/jdk/pull/18539#discussion_r1574301086