RFR: 8329223: Parallel: Parallel GC resizes heap even if -Xms = -Xmx [v9]

[Zhengyu Gu]

On Tue, 30 Apr 2024 15:19:31 GMT, Guoxiong Li <gli at openjdk.org> wrote:

>> 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;
>> 
>> The comment shown below seems strange. Can it be removed?
>> ```C++
>>     // The generation minimums and the overall heap minimum should
>>     // be within one generation alignment.
>> 
>> 
>> 
>> The warning message shown below can be more consistent with this newly added one. 
>> ```C++
>>       log_warning(gc, ergo)("Inconsistency between maximum heap size and maximum "
>>                             "generation sizes: using maximum heap = " SIZE_FORMAT
>>                             ", -XX:OldSize flag is being ignored",
>>                             MaxHeapSize);
>
> If you think they are not related to this bug, it is also OK to fix them in another ticket.

@lgxbslgx Thanks for the review, filed [JDK-8331432](https://bugs.openjdk.org/browse/JDK-8331432)

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PR Review Comment: https://git.openjdk.org/jdk/pull/18539#discussion_r1585110562