Fedora Linux Kernel Overview
Update Schedule
The https://src.fedoraproject.org/rpms/kernel[Fedora Linux kernel] closely follows the upstream https://www.kernel.org/[kernel releases]. To see the current versions in Fedora, https://apps.fedoraproject.org/packages/kernel[check out the packages application].
Stable Releases
Stable releases of Fedora receive two types of kernel updates.
Stable kernel updates
The upstream kernel community support the latest major version with stable updates (4.y.z releases). These updates are released approximately once a week, although they can occur more or less frequently. Once the upstream kernel community makes a stable release, Fedora builds it and submits it as an update to https://bodhi.fedoraproject.org/updates/?packages=kernel[Bodhi]. These updates are typically left in Bodhi for testing for several days before being submitted to the stable updates repository.
Major kernel updates
The Linux kernel releases new major versions (4.y releases) http://phb-crystal-ball.org/[every few months]. When this occurs, Fedora updates to the new major version after a couple upstream stable releases. When the updates are submitted to Bodhi, more time is allowed for testing than stable updates to ensure there are no serious regressions.
Development Releases
The development versions of Fedora include Rawhide and the Branched release.
The Rawhide kernel is the latest git snapshot of Linus' https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/[upstream kernel.org tree]. On a frequent (often daily) basis, a new snapshot is built.
https://fedoraproject.org/wiki/Releases/Branched[Branched releases] receive updates at less frequent intervals than Rawhide. Early on in the Branched release, it is typically using a pre-release version of the kernel, so each Release Candidate (RC) is built for Branched releases. Once the kernel is released, it receives stable updates just like the stable Fedora releases.
Debug Kernels
The Linux kernel offers a number of configuration options to make debugging problems easier. However, some of these options have a performance cost so Fedora does not always turn these options on. When the debugging options have been turned off in the ``kernel`` package, a separate ``kernel-debug`` package is produced with those options on.
Stable and Branched Kernels
Stable and Branched kernels always disable the debugging options.
Rawhide kernels enable the debugging options. However, each release candidate kernel is built with debugging options disabled. Release candidate kernels can be recognized by their release field, which always has the git revision set to 0. For example, ``kernel-4.16.0-0.rc7.git0.1.fc28`` is the 7th release candidate kernel for Fedora 28.