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

On Mon, 16 May 2005, Jens Schweikhardt wrote:

> hello, world\n
>
> the timekeeping on my CURRENT system as of May 15 is very strange. The
> time as reported by date(1) increases too slow by a factor of 3. Things
> with second intervals like sleep 1, tail -f, iostat 1, changing folders
> in mutt all go slower by a factor of 3.
>
> The system bios date however is correct, and a kernel as of March does
> not have this problem, so it's clearly the kernel or some other software
> problem. I have investigated a bit and found the interrupt rates for the
> lapic[01] being three times the value on the broken kernel (about 2kHz
> vs 6kHz),

Are you running with kern.hz or HZ set to something other than the
default?

> schweikh_at_hal9000:~ $ vmstat -i # Good kernel
> interrupt                          total       rate
> irq1: atkbd0                         250          0
> irq3: sio1                             2          0
> irq4: sio0                             2          0
> irq12: psm0                         9079         25
> irq13: npx0                            1          0
> irq14: ata0                           84          0
> irq15: ata1                           77          0
> irq18: em0                          1091          3
> irq24: ahd0                         9112         25
> irq25: ahc0                           16          0
> lapic0: timer                     722947       1997 <-- ~6057 on a bad system
> irq0: clk                         361525        998
> lapic1: timer                     708251       1956 <-- dito
> Total                            1812437       5006 <-- greater than 12000

the lapic timer values should run about 2*hz.

-- 
Doug White                    |  FreeBSD: The Power to Serve
dwhite_at_gumbysoft.com          |  www.FreeBSD.org