[jdk8u-dev] RFR: 8230305: Cgroups v2: Container awareness [v2]

[Poonam Bajaj]

On Wed, 5 Oct 2022 08:26:01 GMT, Jonathan Dowland <jdowland at openjdk.org> wrote:

>> This is a backport of 8230305 (Cgroups v2: Container awareness) for JDK8u, working from the jdk11u-dev backport as part of an effort to backport cgroups v2 to jdk8u-dev.
>> 
>> The patch does not apply clean after unshuffling and path fixing:
>> 
>>  * mostly copyright line issues
>>  * different package name for jdk.test.lib.process.OutputAnalyzer
>>  * Most of hotspot/src/os/linux/vm/cgroupSubsystem_linux.cpp failed due to context changes, manually resolved (mostly deletions)
>> 
>> A few other changes were made
>> 
>>  *  Rework use of newer logging API (log_debug etc) to use guarded tty->print_cr
>>  *  replace os::strerror with the libc strerror (which is thread unsafe, but that should be addressed by backporting 8148425 separately)
>> 
>> patch touched hotspot/test/runtime/containers/docker/TestCPUAwareness.java which passes afterwards; I'm running further tests now (and awaiting GitHub CI doing the same)
>
> Jonathan Dowland has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - substitute os::strerror for strerror
>    
>    os::strerror was introduced in 8148425 (strerror() function is not
>    thread-safe), which is probably out of scope for backporting (at least
>    as part of this cgroups v2 effort). Replace uses of os::strerror with
>    (thread unsafe) strerror, in common with the rest of JDK8u.
>  - Rework use of newer logging API to tty->print_cr
>    
>    Remove includes of log.hpp that doesn't exist in jdk8u
>    
>    log_(debug|trace) to tty->print_cr guarded by PrintContainerInfo
>  - 8230305: Cgroups v2: Container awareness
>    
>    Implement Cgroups v2 container awareness in hotspot
>    
>    Reviewed-by: bobv, dholmes

hotspot/src/os/linux/vm/cgroupV1Subsystem_linux.hpp line 103:

> 101:     CgroupV1Controller* _cpuset = NULL;
> 102:     CachingCgroupController* _cpu = NULL;
> 103:     CgroupV1Controller* _cpuacct = NULL;

For arm32 platform, if the c++ compiler version being used is earlier than 11, then the non-static member initialization will cause compilation failure.

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PR: https://git.openjdk.org/jdk8u-dev/pull/127