1. Please describe the problem:
After upgrading to kernel 6.12, the container support built into Java no longer picks up the correct memory limit - as set by the container runtime.

The problem can be observed by running this command:

    podman run -it -m 2g fedora:41 bash -c "dnf install -y java-headless && java -XX:MaxRAMPercentage=50 -XshowSettings -Xlog:os+container=debug --version"

that was supposed to set the maximum heap memory to 1GB, but with kernel 6.12, sets it to 1/2 the size of the host system.

The problem seems to be related to this change: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=78567e2bc723b444228644d2e34ae5255d4ab8a0, and building the 2.16 kernel with CONFIG_CPUSETS_V1=y also solves the problem.

I would suggest building Fedora kernel with CONFIG_CPUSETS_V1=y until commonly used JDK versions have fixed compatibility with the new cgroups behaviour.


2. What is the Version-Release number of the kernel:
kernel-6.12.6-200.fc41.x86_64


3. Did it work previously in Fedora? If so, what kernel version did the issue
   *first* appear?  Old kernels are available for download at
   https://koji.fedoraproject.org/koji/packageinfo?packageID=8 :
It worked with all versions prior to 6.12

4. Can you reproduce this issue? If so, please provide the steps to reproduce
   the issue below:

   podman run -it -m 2g fedora:41 bash -c "dnf install -y java-headless && java -XX:MaxRAMPercentage=50 -XshowSettings -Xlog:os+container=debug --version"

Expected output: "Max. Heap Size (Estimated): 1.00G" - also on host systems with more than 2GB memory.

5. Does this problem occur with the latest Rawhide kernel? To install the
   Rawhide kernel, run ``sudo dnf install fedora-repos-rawhide`` followed by
   ``sudo dnf update --enablerepo=rawhide kernel``:

Yes, same problem with 6.13.0-0.rc4.36.fc42.x86_64

6. Are you running any modules that not shipped with directly Fedora's kernel?:

No

7. Please attach the kernel logs. You can get the complete kernel log
   for a boot with ``journalctl --no-hostname -k > dmesg.txt``. If the
   issue occurred on a previous boot, use the journalctl ``-b`` flag.

Reproducible: Always