acpi_task_0 consuming cpu resource

[C. C. Tang]

> Not sure then... I've got that board swapped out for a VIA board right
> now.  It tends to be noisy enough in my office with all the other fans
> running that I really can't hear that one.  I did have the smart fan
> control enabled on both the case fan and cpu fan.  It also periodically
> rebuilds lots of ports or kernels with -j 5, so if it was going to heat
> up, that should do it...  If I can dig up a spare case and power, I'll
> hook it back up and see if I can break it.  Otherwise it will have to
> wait until I get done with the VIA driver...  I haven't really had any
> issues that I can think of with that board, other than it is a bit slow
> for compiling.  It runs amd64 just fine.

Really thanks for your reply.
I will keeping watching it to see what situation in which the problem 
will happen.
I am running on i386 version and I think the compile speed is OK for me. 
    Anyway it is not a very fast CPU :)

> Just remembering an issue that I had with some old p4 boxes though.  On
> those boxes, when they got hot, they would trigger an acpi message that
> was picked up by devd.  There was no way to throttle the messages, so it
> would work the cpu as hard as it could, processing the messages.  The
> only solution at that point was to power it off for a few minutes while
> it cooled off and not work it too hard.  That sounds like what you are
> seeing.  Are you seeing messages in syslog?

I have just done a
# stress --cpu 1 --io 1 --vm 1 -d 1
for several hours on the machine.
Although it is not quite stressful, I think it is enough for it to reach 
100% load.
But I didn't notice any such warning in the system log and the 
acpi_task_0 problem didn't appear...

By the way I cannot read any temperature from acpi or smbus except 
coretemp. (may be I loaded wrong driver?)
So I am not sure how hot did the system got.

Thanks,
C.C.