Re: kern/53016: Clock not stable

[Tero Kivinen <kivinen%iki.fi@localhost>]

coypu%sdf.org@localhost writes:
>  A difference is that the drifting first machine's dmesg says:
>  timecounter: Timecounter "clockinterrupt" frequency 100 Hz quality 0
>  ERROR: 4316413966 cycle TSC drift observed

Nothing like that during boot. Dmesg output is of course completely
usable, as it is full of "cprng 461 94681 15: creating with partial
entropy" lines, so cannot know if it has happened after boot:

~>fgrep timecount /var/run/dmesg.boot
timecounter: Timecounters tick every 10.000 msec
timecounter: Timecounter "i8254" frequency 1193182 Hz quality 100
timecounter: Timecounter "ACPI-Fast" frequency 3579545 Hz quality 1000
timecounter: Timecounter "hpet0" frequency 14318180 Hz quality 2000
timecounter: Timecounter "ichlpcib0" frequency 3579545 Hz quality 1000
timecounter: Timecounter "clockinterrupt" frequency 100 Hz quality 0
timecounter: Timecounter "TSC" frequency 2400117960 Hz quality 3000

>  As for this inducing panics, someone mentioned we have some non-ideal
>  behaviour if a clock interrupt is missed (something like: we try to
>  catch up on missed clock interrupts? I wonder if this blows up with very
>  many missed clock interrupts)

Btw, I updated the machine to netbsd 8 from 2018-02-27, and no changes
in the clock drift, but no crash yet (but it has been only up for 7
days since, so cannot say anything yet):

NetBSD vielako.iki.fi 8.0_BETA NetBSD 8.0_BETA (GENERIC) #0: Tue Feb 27 03:12:27 EET 2018 kivinen%vielako.iki.fi@localhost:/usr/obj/sys/arch/amd64/compile/GENERIC amd64
-- 
kivinen%iki.fi@localhost