container support not enabled due to required cgroup subsystems not found

[David Holmes]

Moving to hotspot-dev

On 15/03/2018 8:51 PM, ashutosh mehra wrote:
> When I run  jdk-10+46 build in a docker container, I don't see MaxHeapSize
> being adjusted based on container memory limit.
> 
> Command to run docker container with 2G memory, 2 CPUs:
> $ docker run -m2g --memory-swap=2g --cpus=2 -it --rm -v
> /home/ashu/data/builds/openjdk/jdk-10+46:/root/jdk-10 ubuntu:16.04
> 
> Once inside the container ran the following command:
> 
> # /root/jdk-10//bin/java -XX:+UnlockDiagnosticVMOptions
> -XX:+PrintFlagsFinal -version | grep MaxHeapSize
> 
> Output:
>     size_t MaxHeapSize                              = 2015363072
>                     {product} {ergonomic}
> openjdk version "10" 2018-03-20
> OpenJDK Runtime Environment 18.3 (build 10+46)
> OpenJDK 64-Bit Server VM 18.3 (build 10+46, mixed mode)
> 
> When I used -Xlog:os+container=trace option, I get following information:
> 
> # /root/jdk-10//bin/java "-Xlog:os+container=trace" -version
> 
> [0.001s][trace][os,container] OSContainer::init: Initializing Container
> Support
> [0.001s][debug][os,container] Required cgroup subsystems not found
> openjdk version "10" 2018-03-20
> OpenJDK Runtime Environment 18.3 (build 10+46)
> OpenJDK 64-Bit Server VM 18.3 (build 10+46, mixed mode)
> 
> Following subsystems are present in the docker container:
> # ls /sys/fs/cgroup/
> blkio  cpu  cpuacct  cpuacct,cpu  cpuset  devices  freezer  hugetlb
> memory  net_cls  net_prio  net_prio,net_cls  perf_event  pids  systemd
> 
> As far as I understand, JVM is using only memory, cpu and cpuset subsystems
> which are present in my system. Not sure why is it reporting "Required
> cgroup subsystems not found".
> 
> Any idea what could be wrong here? Are there other debug options to figure
> out what is going wrong?

What does /proc/self/mountinfo show?

David

> Regards,
> Ashutosh Mehra
>