Sorry, missed a link: http://cr.openjdk.java.net/~bobv/8217766/webrev.0/ <http://cr.openjdk.java.net/~bobv/8217766/webrev.0/>
Bob. > On Mar 11, 2019, at 11:13 AM, Bob Vandette <bob.vande...@oracle.com> wrote: > > Please review these three fixes for Linux Docker/cgroup container support. > > https://bugs.openjdk.java.net/browse/JDK-8219562 - Line of code in > osContainer_linux.cpp#L102 appears unreachable > > This change corrects a rarely used hotspot code path to be compatible with > the Java based Metrics. > > https://bugs.openjdk.java.net/browse/JDK-8212528 - Wrong cgroup subsystem > being used for some CPU Container Metrics > > Most Linux distros provide symbolic links for cpuacct and cpu controller > directories. Docker on the Mac does not. > This causes some of the cpu statistics to be unreported. > > https://bugs.openjdk.java.net/browse/JDK-8217766 - Container Support doesn't > work for some Join Controllers combinations > > The cgroup identification -implemented by parsing /proc/self/mountinfo > and /proc/self/cgroup- assumed each cgroup controller was mounted > disjoint from the others (except for "cpu" and "cpuacct" controllers). > Which means, we expected one single controller per mountinfo line. > > This matches the way most Linux distributions currently configure > cgroupsv1 by default. Yet controllers can be grouped arbitrarily. > For instance, using the JoinControllers systemd directive. > One use case for that is to let Kubernetes' kubelet discover his own > dedicated and reserved cgroup hierarchy. In that situation, the JVM > fails to discover the expected cgroup controllers set, and, when running > containerized, default to a suboptimal understanding of available resources. > > Supporting arbitrarily controllers groups per mountpoint actually > allows for simpler and easier to follow code, as we don't need nested > if/else for every controller. > > This fix also updates the Containers Metrics, to support joint controllers. > > Bob. > > >
