I will be committing each change individually but thought I’d save some time testing/reviewing.
Thanks, Bob. > On Mar 18, 2019, at 10:12 AM, Severin Gehwolf <sgehw...@redhat.com> wrote: > > Hi Bob, > > Changes look OK to me. > > I'd prefer if those issues would get addressed separately, though. 3 > webrevs for 3 bugs, over lumping 3 bugs into 1 webrev. This makes it > A) easier to review B) easier to backport to older releases if/when the > time comes. Some of those issues are rather unrelated after all. > > Thanks, > Severin > > On Thu, 2019-03-14 at 10:15 -0400, Bob Vandette wrote: >> Ping ... >> >> >> Please review these three fixes for Linux Docker/cgroup container >> support. >> >> WEBREV: >> >> http://cr.openjdk.java.net/~bobv/8217766/webrev.0 >> >> ISSUE1: >> >> 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 making it >> compatible with the Java based Metrics. >> >> ISSUE2: >> >> 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 since the >> directory name was incorrect. >> >> ISSUE3: >> >> 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 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. >
