Wondering when it is the best[1] time to test the #kernel to prevent #LinuxKernel regressions from hitting #Arch Linux, #Fedora Linux, or #openSUSE #Tumbleweed?
It's now, as the first pre-release of #Linux 6.19 is out – which leaves plenty of time to find, report, debug, and fix any problems that those distros otherwise will encounter when they switch to 6.19.y in about eight to ten weeks. And testing is not even hard, as easy-to-install packages with pre-built mainline kernels exist for all three distros[2].
In case you want to play it a bit safer, delay testing by one week till -rc2 is out – bugs that lead to data loss introduced before -rc1 are extremely rare but will almost certainly have been found and fixed by then.
Anything up to 6.19-rc6 (five weeks from now) is still okayish, but less ideal.
The sixth -rc is your last good chance to test. Linus by then wants all regressions that have become known since the beginning of the 6.19 cycle fixed – but in case some were missed or not reported yet, there is still enough time to report, debug, and fix them before they reach those distros.
Testing any later is often too late: most bugs then can't be fixed anymore before those distros will switch to the 6.19.y series, which will happen within one or two weeks (in the case of Arch and Tumbleweed) or three to four (Fedora) after 6.19 is released.
[1] "best" as in "best tradeoff between risk and impact"
[2] Arch: https://aur.archlinux.org/linux-mainline.git
Fedora: https://copr.fedorainfracloud.org/coprs/g/kernel-vanilla/mainline-wo-mergew/.
Tumbleweed: https://download.opensuse.org/repositories/Kernel:/vanilla/