Timekeeping hosed by factor 3, high lapic[01] interrupt rates

[Doug White]

On Thu, 19 May 2005, Jens Schweikhardt wrote:

> # Are you running with kern.hz or HZ set to something other than the
> # default?
>
> No,
> $ sysctl -a | grep hz
> kern.clockrate: { hz = 1000, tick = 1000, profhz = 666, stathz = 133 }
> debug.psm.hz: 20
>
> is the same on both systems.
> ...
> # the lapic timer values should run about 2*hz.
>
> Then something is out of whack... this is from the strange system:
>
> $ vmstat -i
> interrupt                          total       rate
> irq1: atkbd0                         211          8
> irq13: npx0                            1          0
> irq14: ata0                           63          2
> irq15: ata1                          109          4
> irq18: em0                            17          0
> irq24: ahd0                         4511        187
> irq25: ahc0                           16          0
> lapic0: timer                     190869       7952
> lapic1: timer                     176174       7340
> Total                             371971      15498
>
> Note that there's no
> irq0: clk                         745029       1000
> appearing. I'm not an expert, but that's unexpected to my eyes.

Not totally (I don't have irq0 on any of my -current machines after the
lapic change), but it being there before and then going away implies the
kernel is choosing a different timecounter than before, and the new one
may be bogus.

Can you get the output of 'sysctl kern.timecounter' for both working and
broken kernels?

When did you pull sources for the original working kernel and the new
broken kernel?

> pcib0: <MPTable Host-PCI bridge> pcibus 0 on motherboard

Is ACPI disabled on purpose?  It should work on such a new system. ACPI
provides a couple of timecounters of its own that we'd prefer to use.

-- 
Doug White                    |  FreeBSD: The Power to Serve
dwhite at gumbysoft.com          |  www.FreeBSD.org