[6.9.1] Marking clocksource tsc as unstable

[hawihoney]

In one of my VMs I found this in syslog. A running parity check dropped from 122 MB/s to 17 MB/s:

 

Mar 10 13:04:16 TowerVM02 kernel: clocksource: timekeeping watchdog on CPU6: Marking clocksource 'tsc' as unstable because the skew is too large:
Mar 10 13:04:16 TowerVM02 kernel: clocksource: 'acpi_pm' wd_now: 3664fc wd_last: 62e7a2 mask: ffffff
Mar 10 13:04:16 TowerVM02 kernel: clocksource: 'tsc' cs_now: 43f8233e3b2c cs_last: 43f59d044437 mask: ffffffffffffffff
Mar 10 13:04:16 TowerVM02 kernel: tsc: Marking TSC unstable due to clocksource watchdog
Mar 10 13:04:16 TowerVM02 kernel: TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
Mar 10 13:04:16 TowerVM02 kernel: sched_clock: Marking unstable (26599124145134, 33401162)<-(26599178070430, -20523118)
Mar 10 13:04:16 TowerVM02 kernel: clocksource: Switched to clocksource acpi_pm

 

What's that? BIOS is OVMF from Unraid 6.9.1.

 

Thanks in advance.

 

Edited March 10, 2021 by hawihoney

[hawihoney]

Now on 6.9.2 and new, more powerful hardware this is still happening. The switching clocksource was the reason for the new hardware. Can't believe this is still a problem:

 

root@TowerVM02:~# grep -i clockso /var/log/syslog
Aug 25 09:47:29 TowerVM02 kernel: clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1910969940391419 ns
Aug 25 09:47:29 TowerVM02 kernel: clocksource: tsc-early: mask: 0xffffffffffffffff max_cycles: 0x6a8bec17f92, max_idle_ns: 881590537929 ns
Aug 25 09:47:29 TowerVM02 kernel: clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 1911260446275000 ns
Aug 25 09:47:29 TowerVM02 kernel: clocksource: Switched to clocksource tsc-early
Aug 25 09:47:29 TowerVM02 kernel: clocksource: acpi_pm: mask: 0xffffff max_cycles: 0xffffff, max_idle_ns: 2085701024 ns
Aug 25 09:47:29 TowerVM02 kernel: tsc: Refined TSC clocksource calibration: 3696.019 MHz
Aug 25 09:47:29 TowerVM02 kernel: clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x6a8d4c18613, max_idle_ns: 881590899667 ns
Aug 25 09:47:29 TowerVM02 kernel: clocksource: Switched to clocksource tsc
Sep  1 11:43:10 TowerVM02 kernel: clocksource: timekeeping watchdog on CPU12: Marking clocksource 'tsc' as unstable because the skew is too large:
Sep  1 11:43:10 TowerVM02 kernel: clocksource:                       'acpi_pm' wd_now: 7b3afe wd_last: 5c3c9a mask: ffffff
Sep  1 11:43:10 TowerVM02 kernel: clocksource:                       'tsc' cs_now: 808c642ec585e cs_last: 808c5d4de753e mask: ffffffffffffffff
Sep  1 11:43:10 TowerVM02 kernel: tsc: Marking TSC unstable due to clocksource watchdog
Sep  1 11:43:10 TowerVM02 kernel: clocksource: Switched to clocksource acpi_pm