RFR: 8334513: New test gc/TestAlwaysPreTouchBehavior.java is failing on MacOS aarch64

[Thomas Stuefe]

On Thu, 22 May 2025 08:10:12 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> I exhumed this old issue that fell through the cracks.
>> 
>> The test wants to make sure AlwaysPreTouch works by pretouching the java heap and comparing RSS with heap size. 
>> 
>> This technique is shaky: if the host machine experiences memory pressure, part of the pretouched memory will be swapped out before we measure RSS.
>> 
>> There is no way to make this bulletproof; still, this test is too useful to abandon it. Therefore I modified this test to make false positives (hopefully) very unlikely. See comment in test for details.
>> 
>> See old PR: https://github.com/openjdk/jdk/pull/19803
>
> Makes sense .  Should we add it to our build/test queue for some days to see if it behaves well ?

Thanks @MBaesken and @theRealAph

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PR Comment: https://git.openjdk.org/jdk/pull/25384#issuecomment-2906713276