Upgrade from 9.1 to 9.2 clock issue

K

KernelPanic

I just upgraded three nearly identical servers (Intel sr1500 chassis) from 9.1-RELEASE to 9.2-RELEASE using freebsd-update Since the upgrade, two of the three cannot keep time properly. Even with ntpd running.

Of the two having problems they list four clocks:
Code: 
Timecounter "i8254" frequency 1193182 Hz quality 0
Timecounter "HPET" frequency 14318180 Hz quality 950
Timecounter "ACPI-fast" frequency 3579545 Hz quality 900
Timecounter "TSC-low" frequency 1330029248 Hz quality 1000

FreeBSD 9.2 starts with "TSC-low" as it has the highest quality. I've tried using the other three manually via sysctl kern.timecounter.hardware but they all act the same.

The one running without any problems only lists three clocks:
Code: 
Timecounter "i8254" frequency 1193182 Hz quality 0
Timecounter "ACPI-fast" frequency 3579545 Hz quality 900
Timecounter "TSC-low" frequency 1250071728 Hz quality 1000

The one running without any problems only has one quad-core processor the other two have dual quad-core processors.

I'm still troubleshooting this but aside from disabling ACPI clock (per the FAQ), and maybe pulling out a CPU core I'm running out of ideas fast.
 
Same problem, I posted in the general forum. Fortunately, I was able to switch to the HPET timer, and things are fixed. Something is still off in 9.2, but I have the right time for now.
 
As an update:
I reduced one of the malfunctioning servers to a single (quad core) processor yesterday so it would be more like the server that is operating normally. At the same time I reset the clock on the other ailing server. Since then, I haven't had any issues with clock drift on any server.

The only think they're running that connects the three is inspircd, which runs as an unprivileged user.

Very strange.
 
The second Intel SR1500 chassis started having the same clock skew issue two days later. I pulled the second CPU from it and I have not had any issues since then.

Since these servers were running 9.0 and 9.1 without any problems for over a year, should I submit a PR about this?
 
Did you change kern.timecounter.hardware to
Code: 
kern.timecounter.hardware=LAPIC
For me changing kern.timecounter.hardware did nothing.
 
There is a difference between kern.timecounter and kern.eventtimer on my affected systems. My current settings are:

Code: 
kern.timecounter.choice: TSC-low(1000) ACPI-fast(900) HPET(950) i8254(0) dummy(-1000000)
kern.timecounter.hardware: TSC-low
kern.eventtimer.choice: HPET(450) HPET1(440) HPET2(440) LAPIC(400) i8254(100) RTC(0)
kern.eventtimer.timer: LAPIC

Since my issues have all been about clock skew, I've never considered tinkering with anything other than kern.timecounter. I don't know enough of the underpinnings of FreeBSD to know how the latter would affect the clock. I might as well give
Code: 
kern.eventtimer.timer=HPET
a try since it has a higher quality rating that LAPIC.
 
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