For context: https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/pentium-celeron-n-series-j-series-datasheet-spec-update.pdf
APL30 A Store Instruction May Not Wake up MWAIT Problem: One use of the MONITOR/MWAIT instruction pair is to allow a logical processor to wait in a sleep state until a store to the armed address range occurs. Due to this erratum, stores to the armed address range may not trigger MWAIT to resume execution. Implication : The logical processor that executed the MWAIT instruction may not resume execution until it receives an interrupt. Software that does not rely on stores to the armed address range to wake a logical processor from an MWAIT sleep state is not affected by this erratum. Workaround : Software needs to use interrupts to wake processors from MWAIT-induced sleep states. I got the hint from a reddit comment: https://www.reddit.com/r/PFSENSE/comments/76qag8/240_not_booting_due_to_hpet/dogx84x/ It says you can turn it off in BIOS too, if you don't feel like changing the kernel.
