[8u] RFR: 8227006: [linux] Runtime.availableProcessors execution time increased by factor of 100

[Jonathan Dowland]

Original bug: https://bugs.openjdk.java.net/browse/JDK-8227006
Original rev: https://hg.openjdk.java.net/jdk/jdk/rev/c440a6b4e096

RFR webrev: https://cr.openjdk.java.net/~shade/8227006/webrev.8u.01/

Please review this backport for jdk8u-dev for parity with Oracle JDK 8u281.

The original patch did not apply cleanly to jdk8u-dev. I had to untangle
it from related changes from JDK-8232207.  I also re-worked a call to
"log_trace" to use "tty->print_cr" conditionally on (PrintContainerInfo)
set, matching other uses in the file.

One can see the cache in operation by executing the following and
comparing the output before/after:

    java -XX:+UnlockDiagnosticVMOptions -XX:PrintContainerInfo -version


Best wishes,

-- 
���� Jonathan Dowland <jdowland at redhat.com>
Senior Software Engineer, OpenJDK, Red Hat