RFR: 8267246: -XX:MaxRAMPercentage=0 is unreasonable for jtreg tests on many-core machines [v2]

[Erik Joelsson]

On Tue, 18 May 2021 03:35:11 GMT, Jie Fu <jiefu at openjdk.org> wrote:

>> Hi all,
>> 
>> vmTestbase/vm/mlvm/anonloader/stress/oome/metaspace/Test.java fails on our many-core machines due to `-XX:MaxRAMPercentage=0`.
>> This is because `MaxRAMPercentage` will be always 0 if JTREG_JOBS > 25 [1].
>> 
>> It can be reproduced by: `make test TEST="vmTestbase/vm/mlvm/anonloader/stress/oome/metaspace/Test.java" JTREG="JOBS=26"` on almost all machines.
>> 
>> Setting `-XX:MaxRAMPercentage=0` on many-core machines seems unreasonable.
>> It would be better to fix it.
>> 
>> Thanks.
>> Best regards,
>> Jie
>> 
>> 
>> [1] https://github.com/openjdk/jdk/blob/master/make/RunTests.gmk#L741
>
> Jie Fu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use awk to compute MaxRAMPercentage

Looks good to me, thanks for fixing this!

I took the change for a spin internally running our tier1-3.

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Marked as reviewed by erikj (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/4062