The Linux 6.19 kernel development cycle has hit a speed bump. Linus Torvalds confirmed that release candidate 6 arrived larger than usual, making an eighth RC increasingly likely, adding an extra testing week. Holiday catch-up work and timing fluctuations are the culprits, though the code remains stable.
Torvalds noted this week that RC6 is slightly larger than typical for this stage. While he isn’t overly concerned, he stated that “the slightly larger size does make me think that my plan to do an extra RC8 remains reasonable.” The reasons are straightforward enough. Developers catching up after the Christmas and New Year break contributed to the bulge. Another factor is simply timing: more pull requests arrived simultaneously over the week.
Despite the larger release, there’s no panic. Torvalds emphasized the code is stable and “not chaotic,” with no show-stopper bugs or scary architectural problems lurking. Standard kernel cycles usually go to RC7 before the final release, as Neowin notes. An RC8 adds an extra week of testing. If it materializes, it will ensure the pent-up work hasn’t introduced subtle regressions. Given the fundamental nature of an OS kernel, no one involved in the process of updating it would prefer a rushed release.
What RC6 brings
RC6 brought several notable individual changes. One contributor, Alice Ryhl, submitted a fix for Rust bit operations on 32-bit ARM, showing the continued maturation of Rust in the kernel. There were also multiple updates to the Landlock Linux Security Module (LSM) to fix TCP handling and documentation. More support for various specific hardware arrived as well, such as the PICAXE AXE027 cable and new quirks for Dell and ASUS laptops.
The diffstat looks typical for this stage, Torvalds explained. Drivers dominate about a third of changes—networking and GPU taking the lead, as always. The rest includes selftests, documentation, architecture updates, and various core kernel, memory management, and filesystem updates. Nothing unusual there.
It goes without saying that users should avoid installing this kernel version when it comes out. Your machine will likely not boot after installing it. Actual users have to wait until their distribution receives Linux 6.19 as an official update. The time until rollout varies based on what system you’re running, and many vendors choose not to wait on kernel versions – new distro releases may very well still use a kernel version before 6.19 over the coming months.
Development cycle disruptions
The 6.19 cycle has been somewhat disruptive from the start. Christmas and New Year fell during the early development stages, throwing off the usual rhythm. Torvalds signaled earlier that a delay was probable given the timing. Now, with RC6 confirming the pattern, that extra week of testing looks all but certain.
In his message to the Linux Kernel Mailing List on January 18, Torvalds chalked it up to “some pent-up work from the holidays,” though he noted it might also be random fluctuations in pull request timings. Things started calm last week, but a lot of work came in over the weekend, more pronounced than sometimes is the case.