On OpenBSD on an Atom 450, with HPET configured in the BIOS and not, also with Hyperthreading/ACPI on-off, nothing seems to make a difference.
Here's my vmstat -iz
# vmstat 2
procs memory page disk traps cpu
r b w avm fre flt re pi po fr sr wd0 int sys cs us sy id
0 0 0 3488 981792 429 0 0 0 0 0 35 295771 906 89 1 51 48
0 0 0 3492 981788 12 0 0 0 0 0 0 278490 37 10 0 50 50
^C
# vmstat -iz
interrupt total rate
irq0/clock 12115 102
irq96/inteldrm0 0 0
irq133/ppb0 0 0
irq96/em0 0 0
irq84/ppb1 0 0
irq81/em1 0 0
irq131/ppb2 0 0
irq82/em2 0 0
irq132/ppb3 0 0
irq83/em3 0 0
irq84/uhci0 28 0
irq83/uhci1 0 0
irq84/ehci0 2 0
irq80/pciide0 877 7
irq82/pciide1 0 0
irq81/ichiic0 0 0
irq130/com0 451 3
irq129/pckbc0 0 0
Total 13473 114
The irq0/clock continues to go out of control, this is about 1minute after booting....
# vmstat -s
4096 bytes per page
252939 pages managed
245456 pages free
865 pages active
1015 pages inactive
0 pages being paged out
1 pages wired
0 pages zeroed
4 pages reserved for pagedaemon
6 pages reserved for kernel
132529 swap pages
0 swap pages in use
0 total anon's in system
0 free anon's
17558 page faults
17368 traps
47204661 interrupts
4703 cpu context switches
14 fpu context switches
17854 software interrupts
37197 syscalls
0 pagein operations
0 swap ins
0 swap outs
144 forks
13 forks where vmspace is shared
14 kernel map entries
0 number of times the pagedaemon woke up
0 revolutions of the clock hand
0 pages freed by pagedaemon
0 pages scanned by pagedaemon
0 pages reactivated by pagedaemon
0 busy pages found by pagedaemon
9096 total name lookups
cache hits (67% pos + 1% neg) system 0% per-directory
deletions 0%, falsehits 0%, toolong 0%
0 select collisions
Any ideas to reduce the load, thanks.
This perticular problem was likely asperbated by the fact that OpenBSD's sysctl is anemic. FBSD "poll" sysctl would of likely solved this much earlier.
The problem was due to a poorly written BIOS, specifically it's configuration and implmentation of a console/remote access serial port. It was spinning like crazy and generating these interrupts, even if not connected etc...