On Thu, 20 Jun 2024 12:06:43 GMT, Severin Gehwolf <sgehw...@openjdk.org> wrote:

>> Please review this enhancement to the container detection code which allows 
>> it to figure out whether the JVM is actually running inside a container 
>> (`podman`, `docker`, `crio`), or with some other means that enforces 
>> memory/cpu limits by means of the cgroup filesystem. If neither of those 
>> conditions hold, the JVM runs in not containerized mode, addressing the 
>> issue described in the JBS tracker. For example, on my Linux system 
>> `is_containerized() == false" is being indicated with the following trace 
>> log line:
>> 
>> 
>> [0.001s][debug][os,container] OSContainer::init: is_containerized() = false 
>> because no cpu or memory limit is present
>> 
>> 
>> This state is being exposed by the Java `Metrics` API class using the new 
>> (still JDK internal) `isContainerized()` method. Example:
>> 
>> 
>> java -XshowSettings:system --version
>> Operating System Metrics:
>>     Provider: cgroupv1
>>     System not containerized.
>> openjdk 23-internal 2024-09-17
>> OpenJDK Runtime Environment (fastdebug build 
>> 23-internal-adhoc.sgehwolf.jdk-jdk)
>> OpenJDK 64-Bit Server VM (fastdebug build 
>> 23-internal-adhoc.sgehwolf.jdk-jdk, mixed mode, sharing)
>> 
>> 
>> The basic property this is being built on is the observation that the cgroup 
>> controllers typically get mounted read only into containers. Note that the 
>> current container tests assert that `OSContainer::is_containerized() == 
>> true` in various tests. Therefore, using the heuristic of "is any memory or 
>> cpu limit present" isn't sufficient. I had considered that in an earlier 
>> iteration, but many container tests failed.
>> 
>> Overall, I think, with this patch we improve the current situation of 
>> claiming a containerized system being present when it's actually just a 
>> regular Linux system.
>> 
>> Testing:
>> 
>> - [x] GHA (risc-v failure seems infra related)
>> - [x] Container tests on Linux x86_64 of cgroups v1 and cgroups v2 
>> (including gtests)
>> - [x] Some manual testing using cri-o
>> 
>> Thoughts?
>
> Severin Gehwolf has updated the pull request incrementally with one 
> additional commit since the last revision:
> 
>   Remove problem listing of PlainRead which is reworked here

Currently this patch conflicts a lot with #19085 
(jerboaa:jdk-8331560-cgroup-controller-delegation).

-------------

PR Comment: https://git.openjdk.org/jdk/pull/18201#issuecomment-2188994651

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