RFR: 8220579: [Containers] SubSystem.java out of sync with osContainer_linux.cpp

[Severin Gehwolf]

Hi,

I'm not sure what the right list for Metrics.java[1] is. Assuming it's
serviceability-dev:

Please review this one-liner for for SubSystem.java which currently
behaves differently from the native implementation in
osContainer_linux.cpp. Please see the details in the bug.

Bug: https://bugs.openjdk.java.net/browse/JDK-8220579
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8220579/01/webrev/

Testing:
Manual testing of JDK-8217338 with Metrics.java support with/without
this fix on Linux x86_64. Metrics tests and Docker tests continue to
pass for fastdebug jvms (NOT for release jvms. see JDK-8220674, which
was fun).

Thoughts?

Thanks,
Severin

[1] http://hg.openjdk.java.net/jdk/jdk/file/641768acb12e/src/java.base/linux/classes/jdk/internal/platform/cgroupv1/Metrics.java