ISPN-9091 Determine available CPUs taking CGroup quotas into account

[tristantarrant]

https://issues.jboss.org/browse/ISPN-9091

[tristantarrant]

This is wrong. Closing temporarily

[tristantarrant]

This now uses the same logic adopted by Java 10+ taking into account:

• a system property (infinispan.activeprocessorcount)
• available CPUs as set by taskset
• CGroup CPU shares
• CGroup quota/period allocation

[tristantarrant]

Hints for testing:
Run a docker container with the some quota/period configuration and each of the JDKs:
e.g.
docker run -it --cpu-quota=120000 --cpu-period=10000 [openjdk:8-jdk|openjdk:10-jdk|openjdk:11-jdk]
copy infinispan-commons.jar to the container:
docker cp commons/target/infinispan-commons-9.3.0-SNAPSHOT.jar inspiring_mestorf:/infinispan-commons.jar
From inside the container, run the following:
java -classpath infinispan-commons.jar org.infinispan.commons.util.ProcessorInfo
Try different combinations of cpu-quota/cpu-period

[ryanemerson]

@tristantarrant It appears to be working as expected 👍. On Jdk >= 10 should we not just return Runtime.getRuntime().availableProcessors(); in ProcessorInfo::determineProcessors()?

[tristantarrant]

Yes, but the multi-release jar work is going into my JDK 10+ PR. Once this is in I will adapt #5940 to do just that

[wburns]

Shouldn't we always use the value returned from the setting "infinispan.activeprocessorcount" if it is set?

[tristantarrant]

it does so only if it is less than the available processors.

[wburns]

Okay, from the name I assumed it would be use this setting always type of thing. Just side note but with non linux would always use this value if it is set btw.