The current tentative target kernel for the upcoming Ubuntu release 23.10 (Mantic Minotaur) is 6.5.
Deadlines (Mantic Minotaur Release Schedule):
- 2023-09-14T00:00:00Z: kernel feature freeze
- 2023-09-18T00:00:00Z: beta freeze
- 2023-09-28T00:00:00Z: kernel freeze
- 2023-10-05T00:00:00Z: final freeze
- 2023-10-12T00:00:00Z: final release
An experimental build of the latest Ubuntu mantic kernel based on 6.5-rc1 is already available in ppa:canonical-kernel-team/unstable (https://launchpad.net/~canonical-kernel-team/+archive/ubuntu/unstable), this kernel will be updated weekly, until it will replace the main kernel in 23.10.
Warning: this kernel is still experimental for now, use at your own risk!
Whatâs new in 6.5 (most noticeable changes)
Upstream changes:
- Intelâs âTopology Aware Register and PM Capsule Interfaceâ (interface that provides better power-management features)
- arm64 permission-indirection extension (technology to set special memory permissions)
- RISC-V now supports ACPI
- The Loongarch architecture now supports simultaneous multi-threading (SMT)
- Support for unaccepted memory (protocol by which secure guest systems accept memory allocated by the host - https://lwn.net/Articles/928328/)
- io_uring subsystem can now store the rings and submission queue in user-space memory
- Ability to mount a filesystem underneath an existing mount on the same mount point, useful in container scenarios https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c0a572d9d32f
- New cachestat() system call (query the page-cache state of files and directories)
- Usual set of changes to support new hardware
Ubuntu-specific changes:
- zstd compressed modules (https://bugs.launchpad.net/bugs/2028568) (boot time speed up)
- New Apparmor / Stacking LSM patch set
- Updated shiftfs patch set (bug fixes - done)
- Enabled multi-gen LRU page reclaiming by default (https://bugs.launchpad.net/bugs/2023629)
- Lowlatency kernel gets some desktop-oriented .config tunings (https://bugs.launchpad.net/bugs/2023007)
Open issues
- Rust support now requires rustc 1.68.2 (work in progress: https://bugs.launchpad.net/bugs/2025179)
- Rust support is currently conflicting with CONFIG_UBSAN: build error, it can be fixed with this applied: https://lore.kernel.org/lkml/20230711071914.133946-1-andrea.righi@canonical.com/T/#u
- Building out-of-tree kernel modules as regular user is currently broken due to rustc trying to create temporary files under
/usr/src/linux-headers-$(uname -r), this can be fixed applying the patch reported here:
https://github.com/Rust-for-Linux/linux/issues/1015 - Fix the build of all the supported nvidia drivers (dkms)
Additional non-upstream features that we may consider for inclusion
- new zfs 2.2.0~rc3 (accepted)
- ceph: allow idmapped mounts (accepted)
- sched_ext: BPF extensible scheduler class: feature that allows developers to implement custom scheduling policies using BPF programs (https://lore.kernel.org/lkml/20230711011412.100319-1-tj@kernel.org/) (rejected)