RFR: 8236617: jtreg test containers/docker/TestMemoryAwareness.java fails after 8226575

[Baesken, Matthias]

Hello, please review this small adjustment to  jtreg test  containers/docker/TestMemoryAwareness.java .

After change   "8226575: OperatingSystemMXBean should be made container aware"    has been pushed,
we observe failures on linux s390x / ppc64le in the docker related jtreg tests  .


The test runs into  the following error :
java.lang.RuntimeException: 'OperatingSystemMXBean.getTotalSwapSpaceSize: 52428800' missing from stdout/stderr

at jdk.test.lib.process.OutputAnalyzer.shouldContain(OutputAnalyzer.java:187)
at TestMemoryAwareness.testOperatingSystemMXBeanAwareness(TestMemoryAwareness.java:154)
at TestMemoryAwareness.main(TestMemoryAwareness.java:65)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
at java.base/java.lang.Thread.run(Thread.java:832)


The reason is that the value found is instead     OperatingSystemMXBean.getTotalSwapSpaceSize: -104857600    .
When looking into the getTotalSwapSpaceSize() function, we get values of 0 for "limit" and 104857600 for "memLimit" :

57 long limit = containerMetrics.getMemoryAndSwapLimit();
 ....
62 long memLimit = containerMetrics.getMemoryLimit();
63 if (limit >= 0 && memLimit >= 0) {
64 return limit - memLimit;
65 }

That explains the value "-104857600" . We see messages    "Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap" , this most likely
causes the unexpected limit == 0  value  .


Bug/webrev :

https://bugs.openjdk.java.net/browse/JDK-8236617

http://cr.openjdk.java.net/~mbaesken/webrevs/8236617.0/


Thanks, Matthias