8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10

[iklam]

When running on Ubuntu 21.10 (which has cgroupv2 enabled by default) but outside of a container, the VM was printing only this:

[0.114s][debug][os,container] 
   Open of file /sys/fs/cgroup/user.slice/user-529964.slice/session-1168.scope/cpu.weight failed,
   No such file or directory

After my fix, this is also printed to make the PlainRead.java test happy:

[0.114s][trace][os,container] Raw value for CPU Shares is: -2

Note that the GET_CONTAINER_INFO_CPTR and GET_CONTAINER_INFO_LINE macros still don't print the trace log when the requested file doesn't exist. I don't know whether I should change them or not. Since no tests seem to look for such a such a log message, I'll leave the code as-is for now.

---

Progress

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Issue

• JDK-8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10

Reviewers

• Harold Seigel (@hseigel - Reviewer)
• Severin Gehwolf (@jerboaa - Reviewer)

Reviewing

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Update a local copy of the PR:
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$ git pull https://git.openjdk.java.net/jdk pull/7043/head

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$ git pr checkout 7043

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https://git.openjdk.java.net/jdk/pull/7043.diff

[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 00: Full (ff850fe4)

[hseigel]

Changes look good.
Thanks! Harold

[openjdk]

@iklam This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8278951: containers/cgroup/PlainRead.java fails on Ubuntu 21.10

Reviewed-by: hseigel, sgehwolf

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 25 new commits pushed to the master branch:

• b61a4af: 8259774: Deprecate -XX:FlightRecorderOptions:samplethreads
• 6933934: 8278597: Remove outdated comments regarding RMISecurityManager in HotSpotAgent.java
• 4851948: 8279903: Redundant modulo operation in ECDHKeyAgreement
• 67e3d51: Merge
• 5aecb37: 8206181: ExceptionInInitializerError: improve handling of exceptions in user-provided taglets
• 86d0abb: 8279695: [TESTBUG] modify compiler/loopopts/TestSkeletonPredicateNegation.java to run on C1 also
• 6d7db4b: 8279356: Method linking fails with guarantee(mh->adapter() != NULL) failed: Adapter blob must already exist!
• 92307e5: 8278489: Preserve result in native wrapper with +UseHeavyMonitors
• bbc1ddb: 8278267: ARM32: several vector test failures for ASHR
• cb25029: 8279800: isAssignableFrom checks in AlgorithmParametersSpi.engineGetParameterSpec appear to be backwards
• ... and 15 more: https://git.openjdk.java.net/jdk/compare/3aaa0982d8c1735208a331b0097a5aea4a1fef5a...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[jerboaa]

Looks fine to me.

Note: I first wondered whether we needed to handle a OSCONTAINER_ERROR value in CgroupV2Subsystem::cpu_shares() but we don't as in that case the function returns early (-2) and CgroupSubsystem::active_processor_count() handles negative values appropriately.

[iklam]

Hi @hseigel and @jerboaa thanks for the review.
/integrate

[openjdk]

Going to push as commit 35172cd.
Since your change was applied there have been 30 commits pushed to the master branch:

• 237f861: 8273143: Transition to _thread_in_vm when handling a polling page exception
• 9209e6d: 8279877: Document IDEA IDE setup in docs/ide.md
• 0a839b4: 8279801: EC KeyFactory and KeyPairGenerator do not have aliases for OID format
• 6fcaa32: 8262442: (windows) Use all proxy configuration sources when java.net.useSystemProxies=true
• c17a012: 8278961: Enable debug logging in java/net/DatagramSocket/SendDatagramToBadAddress.java
• b61a4af: 8259774: Deprecate -XX:FlightRecorderOptions:samplethreads
• 6933934: 8278597: Remove outdated comments regarding RMISecurityManager in HotSpotAgent.java
• 4851948: 8279903: Redundant modulo operation in ECDHKeyAgreement
• 67e3d51: Merge
• 5aecb37: 8206181: ExceptionInInitializerError: improve handling of exceptions in user-provided taglets
• ... and 20 more: https://git.openjdk.java.net/jdk/compare/3aaa0982d8c1735208a331b0097a5aea4a1fef5a...master

Your commit was automatically rebased without conflicts.

[openjdk]

@iklam Pushed as commit 35172cd.

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