Date: Fri, 16 Jul 2010 12:31:10 -0700 From: Rob Farmer <rfarmer@predatorlabs.net> To: Alexander Motin <mav@freebsd.org> Cc: current <current@freebsd.org> Subject: Re: Clock not moving in virtual machine Message-ID: <AANLkTilCKUtVEiViEN_EoCMGl7KvryVXEd-sWuxFjzsS@mail.gmail.com> In-Reply-To: <4C3FFD3F.7060909@FreeBSD.org> References: <mailpost.1279239004.5520450.26216.mailing.freebsd.current@FreeBSD.cs.nctu.edu.tw> <4C3FFD3F.7060909@FreeBSD.org>
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On Thu, Jul 15, 2010 at 11:33 PM, Alexander Motin <mav@freebsd.org> wrote:
> Rob Farmer wrote:
>> I have a VPS from rootbsd.net which is running current, though I don't
>> update it very often. I just built and installed a new world and
>> kernel and now the clock will not move from the time the system was
>> booted, ie:
>> # date
>> Thu Jul 15 16:15:58 PDT 2010
>> <wait a minute>
>> # date
>> Thu Jul 15 16:15:58 PDT 2010
>>
>> I have an old kernel from May 27 which doesn't have this problem. I
>> noticed some clock related stuff changing in current in the last
>> couple of weeks and suspect that their VM setup doesn't play well with
>> these changes (their site says they use Xen, but several boot messages
>> refer to QEMU). Officially, I think they only support running 8.0 so I
>> thought I would ask here if anyone has any ideas before putting in a
>> support request.
>>
>> Here's a diff of the dmesgs - I can post full copies if needed but
>> didn't want to start with a ridicously long message:
>
>> =A0FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
>> =A0FreeBSD/SMP: 0 package(s) x 16 core(s) x 2 SMT threads
>> =A0 cpu0 (BSP): APIC ID: =A00
>
> Probably not related, but funny. :) So you have two CPUs?
Yes, there's 2 CPUs. It also gives the non uniform processors warning,
but it has been like that forever.
>
>> @@ -81,7 +81,10 @@
>> =A0ppc0: Generic chipset (NIBBLE-only) in COMPATIBLE mode
>> =A0ppc0: [ITHREAD]
>> =A0ppbus0: <Parallel port bus> on ppc0
>> -atrtc0: <AT Real Time Clock> at port 0x70 irq 8 on isa0
>> +atrtc0: <AT realtime clock> at port 0x70 irq 8 on isa0
>> +atrtc0: [FILTER]
>> +Event timer "RTC" frequency 32768 Hz quality 0
>> +Starting kernel event timers: LAPIC @ 200Hz, RTC @ 128Hz
>> =A0Timecounters tick every 5.000 msec
>
> Everything seems reasonable there. Try to collect more information:
> sysctl kern.timecounter
> sysctl kern.eventtimer
> vmstat -ia
> systat -vm 1 (presence and frequencies of interrupts)
>
> It could be a bug in emulation of some timers or bug in respective timer
> driver, which was not triggered before last changes. You may try switch
> to different timecounter by setting kern.timecounter.hardware, or
> different eventtimers by setting kern.eventtimer.timer1 and
> kern.eventtimer.timer2 sysctls.
>
> --
> Alexander Motin
>
This is all on the new (not-working) kernel in single user mode:
# sysctl kern.timecounter
kern.timecounter.tick: 1
kern.timecounter.choice: TSC(-100) dummy(-1000000)
kern.timecounter.hardware: dummy
kern.timecounter.stepwarnings: 0
kern.timecounter.tc.TSC.mask: 4294967295
kern.timecounter.tc.TSC.counter: 205772785
kern.timecounter.tc.TSC.frequency: 2261052646
kern.timecounter.tc.TSC.quality: -100
kern.timecounter.smp_tsc: 0
kern.timecounter.invariant_tsc: 1
kern.timecounter.tc.TSC.counter changes everytime (205772785,
3200717147, 1205899870, ...) but I can't see any pattern.
# sysctl kern.eventtimer
kern.eventtimer.choice: LAPIC(500) RTC(0)
kern.eventtimer.et.LAPIC.flags: 15
kern.eventtimer.et.LAPIC.frequency: 50001404
kern.eventtimer.et.LAPIC.quality: 500
kern.eventtimer.et.RTC.flags: 1
kern.eventtimer.et.RTC.frequency: 32768
kern.eventtimer.et.RTC.quality: 0
kern.eventtimer.timer2: RTC
kern.eventtimer.timer1: LAPIC
kern.eventtimer.singlemul: 4
# vmstat -ia
interrupt total rate
??? 0 0
irq1: atkbd0 339 339
stray irq1 0 0
irq0: 0 0
stray irq0 0 0
irq3: 0 0
stray irq3 0 0
irq4: uart0 0 0
stray irq4 0 0
irq5: re0 0 0
stray irq5 0 0
irq6: 0 0
stray irq6 0 0
irq7: ppc0 0 0
stray irq7 0 0
irq8: atrtc0 24463 24463
stray irq8 0 0
irq9: 0 0
stray irq9 0 0
irq10: re1 0 0
stray irq10 0 0
irq11: 0 0
stray irq11 0 0
irq12: psm0 0 0
stray irq12 0 0
irq13: 0 0
stray irq13 0 0
irq14: ata0 224 224
stray irq14 0 0
irq15: ata1 0 0
stray irq15 0 0
irq16: 0 0
stray irq16 0 0
irq17: 0 0
stray irq17 0 0
irq18: 0 0
stray irq18 0 0
irq19: 0 0
stray irq19 0 0
irq20: 0 0
stray irq20 0 0
irq21: 0 0
stray irq21 0 0
irq22: 0 0
stray irq22 0 0
irq23: 0 0
stray irq23 0 0
irq24: 0 0
stray irq24 0 0
irq25: 0 0
stray irq25 0 0
irq26: 0 0
stray irq26 0 0
irq27: 0 0
stray irq27 0 0
irq28: 0 0
stray irq28 0 0
irq29: 0 0
stray irq29 0 0
irq30: 0 0
stray irq30 0 0
irq31: 0 0
stray irq31 0 0
irq32: 0 0
stray irq32 0 0
irq33: 0 0
stray irq33 0 0
irq34: 0 0
stray irq34 0 0
irq35: 0 0
stray irq35 0 0
irq36: 0 0
stray irq36 0 0
irq37: 0 0
stray irq37 0 0
irq38: 0 0
stray irq38 0 0
irq39: 0 0
stray irq39 0 0
irq40: 0 0
stray irq40 0 0
irq41: 0 0
stray irq41 0 0
irq42: 0 0
stray irq42 0 0
irq43: 0 0
stray irq43 0 0
irq44: 0 0
stray irq44 0 0
irq45: 0 0
stray irq45 0 0
irq46: 0 0
stray irq46 0 0
irq47: 0 0
stray irq47 0 0
cpu0:timer 38223 38223
cpu1:timer 38220 38220
Total 101469 101469
systat -ia cycles between:
526 total
atkbd0 1
128 atrtc0 8
ata0 irq14
199 cpu0:timer
199 cpu1:timer
530 total
atkbd0 1
128 atrtc0 8
ata0 irq14
201 cpu0:timer
201 cpu1:timer
If I set kern.eventtimer.timer1=3D"RTC", dmesg says:
Starting kernel event timers: RTC @ 200Hz, LAPIC @ 128Hz
Event timer "LAPIC" is dead.
Starting kernel event timers: RTC @ 800Hz, NONE @ 0Hz
The clock still doesn't move though.
On the old kernel I had i8254 in the dmesg and that appears to be what was =
used:
kern.timecounter.tick: 1
kern.timecounter.choice: TSC(-100) i8254(0) dummy(-1000000)
kern.timecounter.hardware: i8254
kern.timecounter.stepwarnings: 0
kern.timecounter.tc.i8254.mask: 65535
kern.timecounter.tc.i8254.counter: 51889
kern.timecounter.tc.i8254.frequency: 1193182
kern.timecounter.tc.i8254.quality: 0
kern.timecounter.tc.TSC.mask: 4294967295
kern.timecounter.tc.TSC.counter: 266155055
kern.timecounter.tc.TSC.frequency: 2261010847
kern.timecounter.tc.TSC.quality: -100
kern.timecounter.smp_tsc: 0
kern.timecounter.invariant_tsc: 1
Also, in the old kernel, there was nothing on irq8 in vmstat:
irq8: 0 0
stray irq8 0 0
At the loader prompt I tried entering set
kern.timecounter.hardware=3D"i8254" and set
kern.timecounter.hardware=3D"TSC" and they appear set correctly if I
type show, but when I boot, the sysctl is back to dummy.
I have zero knowledge of this kind of thing, but I looks to me like I
need to be using i8254 and the new kernel is not detecting this
device. Is there a hint or something I can set to try and pick up this
device again?
Thanks,
--=20
Rob Farmer
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