This issue is only intended for Noble, though it's not clear to me if I have appropriate permissions to constrain it to just a few releases.
I've prepared a patch to implement this support and will send it to the Ubuntu kernel team's list shortly. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2122368 Title: Re-enable memcg v1 on Noble (6.14) Status in linux package in Ubuntu: New Bug description: [Impact] Although v1 cgroups are deprecated in Noble, it was still possible for users on 6.8 kernels to utilize them. This was especially helpful in helping migrating users to Noble and then separately upgrading their remaining v1 cgroups applications. Instead of requiring all users to upgrade and fix their v2 support, v1 support could be provisionally enabled until the necessary support was available in the applications that still lack v2 support. Starting in 6.12, CONFIG_MEMCG_V1 was added and defaulted to false. Noble 6.8 users that were unlucky enough to still need V1 cgroups found that they could no longer use memcgs in the 6.14 kernel. Specific use cases include older JVMs that fail to correctly handle missing controllers from /proc/cgroups. In that case, the container limit detection is turned off and the JVM uses the host's limits. Further, Apache Yarn is still completing their v1 -> v2 migration, which leaves some Hadoop use cases without proper support. The request here is to enable MEMCG_V1 on Noble, but not newer releases, for as long as the Noble HWE kernel train still has kernels with cgroup v1 support. This gives users a little bit longer to complete their migration while still using newer hardware, but with the understanding that this really is the end of the line for v1 cgroups. [Fix] Re-enable CONFIG_MEMCG_V1 in the 6.14 Noble config. [Test] Booted a kernel with this change and validated that v1 memcgs were present again. [Potential Regression] The regression potential here should be low since this merely restores and existing feature that most users were not using but that a few still depended upon. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2122368/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
