HPET timekeeping

June 2010


I kept getting messages like set_rtc_mmss: can't update from 0 to 59, every now and then, and they would come in batches. The PC would slow down a lot, and timekeeping would miss several hours within a few hours. Just prior to such a batch of set_rtc_mmss messages, I would see one Clocksource tsc unstable message.

So I read a mail thread, a forum and another thread, and also some ntp.org docs. Then I

  1. removed the boot parameters

    noapic nolapic acpi=off

    ,

  2. and added boot parameter

    clocksource=hpet

    ,

  3. and rebooted.

Now the hpet is time source:

jurjen@host:~$ sudo cat /sys/devices/system/clocksource/clocksource0/current_clocksourcehpet