RFR: 8334010: VM crashes with ObjectAlignmentInBytes > GCCardSizeInBytes [v2]

[Thomas Schatzl]

On Tue, 15 Oct 2024 08:38:01 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   * shade review
>
> test/hotspot/jtreg/gc/TestObjectAlignmentCardSize.java line 43:
> 
>> 41:         "-XX:GCCardSizeInBytes=" + cardSize,
>> 42:         "-Xmx32m",
>> 43:         "-Xms32m",
> 
> I wonder if we are playing close to heap limits here, especially with large `ObjectAlignmentInBytes`. Do you have a feeling how much of the heap is used with `ObjectAlignmentInBytes=512`? Should this be `128m` instead, maybe?

The gc+heap+exit memory usage shows <5m memory usage for all GCs (G1, Shenandoah, Serial, Parallel). We could go even lower to 16m easily.

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PR Review Comment: https://git.openjdk.org/jdk/pull/21515#discussion_r1800731877