container support not enabled due to required cgroup subsystems not found

[Bob Vandette]

> On Mar 15, 2018, at 9:01 AM, Bob Vandette <bob.vandette at oracle.com> wrote:
> 
> 
> 
>> On Mar 15, 2018, at 8:55 AM, Baesken, Matthias <matthias.baesken at sap.com> wrote:
>> 
>>> 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
>> 
>> Hi,  in  jdk10  
>> 
>> "cpu,cpuacct”
>> 
> 
> His system has  “cpu” and “cpuacct” links so that shouldn’t be the issue.

I take that back.  If mountinfo only has a  cpuacct,cpu entry, we will fail detection in JDK10.

Bob.

> 
> Bob.
> 
> 
>> 
>> Is checked  as well , see
>> 
>> http://hg.openjdk.java.net/jdk/jdk10/file/b09e56145e11/src/hotspot/os/linux/osContainer_linux.cpp
>> 
>> ( but unfortunately  not  cpuacct,cpu  ).
>> This might cause  the message  :
>> 
>>> [0.001s][debug][os,container] Required cgroup subsystems not found
>> 
>> 
>> In  jdk11  both  "cpu,cpuacct"  and  "cpuacct,cpu"   are checked .
>> Jdk11  has also  a bit better  logging , so I think it would tell  you what  subsystem  is  not found .
>> Could you maybe   rerun  with jdk11  ?
>> 
>> 
>> Thanks, Matthias
>> 
>> 
>> 
>>> -----Original Message-----
>>> From: jdk-dev [mailto:jdk-dev-bounces at openjdk.java.net] On Behalf Of
>>> ashutosh mehra
>>> Sent: Donnerstag, 15. März 2018 11:52
>>> To: jdk-dev at openjdk.java.net
>>> Subject: container support not enabled due to required cgroup subsystems
>>> not found
>>> 
>>> 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?
>>> 
>>> Regards,
>>> Ashutosh Mehra
>