"swiN: clock sio" process taking 75% CPU

[Gareth McCaughan]

I wrote, inter alia,

> About 6 minutes after booting (on two occasions; I don't
> guarantee that this doesn't vary), a process that appears
> in the output of "ps" as "[swi4: clock sio]" begins to
> use about 3/4 of the machine's CPU. I think it does so
> more or less instantaneously. It continues to do so
> indefinitely, so far as I can tell.

David Wolfskill e-mailed me off-list to suggest looking at
the output of "vmstat -i". Answer: the interrupt rates all
appear to be normal, or at least similar to those he observes
on his machines which don't exhibit my problem. More specifically ...

---------- excerpt from my reply to David begins ----------
I get this:

  | interrupt                          total       rate
  | irq1: atkbd0                           3          0
  | irq6: fdc0                            10          0
  | irq14: ata0                         2913          1
  | irq15: ata1                           47          0
  | irq17: xl0                          7342          4
  | cpu0: timer                       302649        199
  | Total                             312964        206

(so the rate of timer interrupts doesn't appear to be
insane)

and

  |  7:56PM  up 26 mins, 1 user, load averages: 1.87, 1.45, 1.08

(so the cost in CPU cycles of servicing them -- if that's what
the rogue process is doing, which seems somewhat plausible --
*does* appear to be insane).
---------- excerpt from my reply to David ends ----------

-- 
g