RFR: 8347126: gc/stress/TestStressG1Uncommit.java gets OOM-killed [v2]

[Thomas Schatzl]

On Wed, 8 Jan 2025 09:20:16 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> One of my testing nodes caught the OOM kill for the VM carrying the test. The default configuration turns the VM that test runs as the driver into a memory hog. On 48-core / 64G machine, the test configured itself to take 13 workers each allocating 1G. This ballooned the heap size to 13G -- e.g. about 25% of host memory  -- which is well beyond the usual footprint for a single test VM (~2GB). Naturally, this runs into a high chance of being OOM killed under high test parallelism.
>> 
>> I think the solution is to cut down the heap size we run with, and balance the number of workers a bit more finely. I looked around at sibling tests and 1G seems to be a common heap size for these tests.
>
> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix math

Marked as reviewed by tschatzl (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/22954#pullrequestreview-2537314050