RFR: 8371420: Still sporadic failures of gc/TestAlwaysPreTouchBehavior.java#<gcname> on Linux after JDK-8359104 [v2]

[Albert Mingkun Yang]

On Wed, 10 Dec 2025 12:34:56 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> After [JDK-8359104](https://bugs.openjdk.org/browse/JDK-8359104) where getting RSS was improved, we still see sporadic failures of the test gc/TestAlwaysPreTouchBehavior.java#<gcname> , for different gcs.
>> E.g. gc/TestAlwaysPreTouchBehavior.java#Epsilon (with -Xlog:os=debug added for more output) 
>> 
>> 
>> ----------System.err:(13/1278)----------
>> java.lang.RuntimeException: RSS of this process(24465408b) should be bigger than or equal to heap size(268435456b) (available memory: 16295006208). On Linux Kernel < 4.14 RSS can be inaccurate: expected 24465408 > 268435456
>> 
>> 
>> Looks like the RSS values we get are somewhat delayed/inaccurate .
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add a comment about RSS values and adjust indentation

Looks reasonable. I wonder if it makes sense to extract the loop-body into a method so that the retrying logic are not intertwined with each attempt.

Additionally, there seems a preexisting issue that the else branch of `(available > requiredAvailable)` should probably also throw `SkippedException`?

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PR Review: https://git.openjdk.org/jdk/pull/28735#pullrequestreview-3562444765