Linux 4.18 Is Appearing To Cause Problems For Those Running Older CPUs

As a P.S.A. for those tending to quickly upgrade to new major kernel releases but are doing so on older hardware, there appears to be a show-stopping bug that made it into the stable Linux 4.18 series.

A Phoronix reader today relayed the discoveries that he and several other Arch Linux users uncovered about running Linux 4.18 on what appears to be isolated to Intel Core 2 Duo era processors. When booting on Linux 4.18 (at least through 4.18.5), there will be an early boot CPU stall and a complete system freeze.

Those encountering this problem have bisected it to clocksource: Remove kthread as the problematic commit. If building the Linux 4.18 kernel with that commit reverted, those old CPUs begin to happily run on this latest stable kernel release. Another alternative to workaround this problem is booting with the kernel parameter of clocksource=hpet. Of course, if you are running on a system as old as the Core 2 Duo days (2006~2010), you can choose any number of older stable Linux LTS releases to boot your system until this situation is resolved upstream and back-ported to the 4.18 series.

Arch Linux users have been exchanging messages over this problem via this forum thread. There are at least two upstream bug reports (one and two) today about this problem.