Re: Failing back to INSANE timesource :) Time stopped today.

From: john stultz
Date: Wed Apr 14 2004 - 13:39:10 EST


On Wed, 2004-04-14 at 01:54, Niclas Gustafsson wrote:
> Now it happened again, with my newly compiled kernel, I've attached the
> config file and dmesg for this kernel.
>
> Watching the /proc/interrupts with 10s apart after the "stop".
>
> [root@s151 root]# more /proc/interrupts
> CPU0
> 0: 66413955 local-APIC-edge timer
> 2: 0 XT-PIC cascade
> 9: 1 IO-APIC-level acpi
> 10: 0 IO-APIC-level ohci_hcd
> 14: 24 IO-APIC-edge ide0
> 20: 31244 IO-APIC-level aic7xxx
> 22: 19652139 IO-APIC-level eth0
> NMI: 0
> LOC: 67379568
> ERR: 0
> MIS: 0
>
> And some 10-15 min later:
>
> [root@s151 root]# cat /proc/interrupts
> CPU0
> 0: 66413964 local-APIC-edge timer
> 2: 0 XT-PIC cascade
> 9: 1 IO-APIC-level acpi
> 10: 0 IO-APIC-level ohci_hcd
> 14: 24 IO-APIC-edge ide0
> 20: 31245 IO-APIC-level aic7xxx
> 22: 19754446 IO-APIC-level eth0
> NMI: 0
> LOC: 68366976
> ERR: 0
> MIS: 0

Wow, clearly something is going wrong with interrupt delivery. You only
received 9 timer interrupts in 10 seconds!

> Worth noticing is the extreme increase in interrupts and context
> switches on the last output line from vmstat, however if this is a true
> picture of what happened or not I cannot say. Maybe this is just a
> result of timing problems?
>
> However I see an increase in network activity just before the stop, the
> system goes from 2 Mbps output to about 55 Mbps on the last read. (Also
> read from this machine so I don't know about it's validity)

Yea, those values are both junk as the X/sec ratio is totally skewed.

> Where can I see what the system is currently using as a timing source
> (TSC/HPET/PIT etc.)?

Note the "Using tsc for high-res timesource" in your dmesg.

I'm working now to reproduce this w/ a 2G system here in our lab, and
just for completeness, could you also send me your BIOS revision number?

thanks
-john


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