Arch Linux

zse

Member

Registered: 2024-05-28

Posts: 47

AMD 7735U: Marking clocksource 'tsc' as unstable

I am getting the following kernel warning on my system quite often, at a seemingly random time usually long after boot:

[ 2176.285004] clocksource: timekeeping watchdog on CPU0: Marking clocksource 'tsc' as unstable because the skew is too large:
[ 2176.285035] clocksource:                       'hpet' wd_nsec: 504668260 wd_now: 4140ca58 wd_last: 40d2880d mask: ffffffff
[ 2176.285049] clocksource:                       'tsc' cs_nsec: 505143811 cs_now: 558dab1fb17 cs_last: 558898db935 mask: ffffffffffffffff
[ 2176.285059] clocksource:                       Clocksource 'tsc' skewed 475551 ns (0 ms) over watchdog 'hpet' interval of 504668260 ns (504 ms)
[ 2176.285070] clocksource:                       'tsc' is current clocksource.
[ 2176.285090] tsc: Marking TSC unstable due to clocksource watchdog
[ 2176.285132] TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
[ 2176.285138] sched_clock: Marking unstable (2176598534315, -313402596)<-(2176308939247, -23809858)
[ 2176.285498] clocksource: Checking clocksource tsc synchronization from CPU 7 to CPUs 0-3,5,13,15.
[ 2176.285740] clocksource: Switched to clocksource hpet

The CPU number is also not always the same, but can be anything from 0-15.

I haven't noticed any problem with the system otherwise, but it would be nice to know what that is, or whether other people have the same issue.

qu@rk

Member

Registered: 2021-07-28

Posts: 149

Re: AMD 7735U: Marking clocksource 'tsc' as unstable

What motherboard/laptop?
I see a few mentions on Wiki
https://wiki.archlinux.org/title/Lenovo … mp_counter
https://wiki.archlinux.org/title/HP_Lap … l_warnings
What's the output of

# cat /sys/devices/system/clocksource/clocksource*/current_clocksource

and

# cat /sys/devices/system/clocksource/clocksource*/available_clocksource

zse

Member

Registered: 2024-05-28

Posts: 47

Re: AMD 7735U: Marking clocksource 'tsc' as unstable

Laptop is Lenovo Yoga 7 14ARP8

At my current boot the problem hasn't happened yet.

$ cat /sys/devices/system/clocksource/clocksource*/current_clocksource
tsc
$ cat /sys/devices/system/clocksource/clocksource*/available_clocksource
tsc hpet acpi_pm 

Those other mentions seem to see this problem very quickly after boot or reboot, while I'm getting it sometimes hours later.

qu@rk

Member

Registered: 2021-07-28

Posts: 149

Re: AMD 7735U: Marking clocksource 'tsc' as unstable

If you do not game on your laptop you could change to hpet.