vmstat reporting incorrect cpu usage
Matt Emmerton
matt at gsicomp.on.ca
Sat Jun 4 14:58:35 GMT 2005
----- Original Message -----
From: "Neo-Vortex" <root at Neo-Vortex.net>
To: <freebsd-hackers at freebsd.org>
Sent: Saturday, June 04, 2005 10:01 AM
Subject: vmstat reporting incorrect cpu usage
> I've noticed if i run vmstat with no params when rebuilding the kernel i
> get this right:
>
> # vmstat
> procs memory page disk faults cpu
> r b w avm fre flt re pi po fr sr ad0 in sy cs us sy id
> 2 1 0 294156 44596 313 0 0 0 296 1 0 82 85 225 14 8 78
> #
>
> But, if i run it like this
>
> # vmstat -c 2
> procs memory page disk faults cpu
> r b w avm fre flt re pi po fr sr ad0 in sy cs us sy id
> 1 1 0 299580 38204 313 0 0 0 296 1 0 82 85 225 14 8 78
> 1 1 0 294996 42876 886 0 0 0 2061 0 3 2222 1364 2231 81 19 0
> #
>
> The second result shows what top does, but the first one seems to be
> completely wrong...
>
> # vmstat -c 6
> procs memory page disk faults cpu
> r b w avm fre flt re pi po fr sr ad0 in sy cs us sy id
> 1 1 0 300136 36196 313 0 0 0 296 1 0 82 85 225 14 8 78
> 1 1 0 301040 35312 230 0 0 0 9 0 0 2193 489 2156 87 13 0
> 1 1 0 296720 39644 1234 0 0 0 2326 0 5 2190 1530 2185 70 30 0
> 1 1 0 297092 39228 1435 0 0 0 1336 0 3 2200 1562 2188 75 25 0
> 1 1 0 298488 37844 1573 0 0 0 1229 0 4 2206 1592 2191 69 31 0
> 1 1 0 299372 36908 316 0 0 0 123 0 96 2301 618 2442 86 14 0
> #
>
> Only the first one seems to do it though...
>
> FreeBSD 5.3-RELEASE.
>
> Does this happen for anyone else? (Mabe someone running 5.4 can test
> this?)
The first line is the average since the system was last booted; all other
lines are instantaneous.
--
Matt Emmerton
More information about the freebsd-hackers
mailing list