kacpid + kacpi_notify thrash CPU on CentOS 6?

[Oleg Goldshmidt]

On Wed, Jul 18, 2012 at 1:54 PM, Oleg Goldshmidt <pub at goldshmidt.org> wrote:

> Hi,
>
> I have a new computer with CentOS 6. I happened to start a rather long
> task that I think is memory-, but not CPU-, intensive. Just for the fun of
> it I started top, and was very surprised to see that the first two lines
> were always
>
>  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+
> COMMAND
>
>    38 root     20   0     0    0    0 R 66.2  0.0   2671:58
> kacpid
>
>    39 root     20   0     0    0    0 S 32.6  0.0   1320:31
> kacpi_notify
>
> It looks a lot like various issues with laptops from way back, e.g.,
> https://bugzilla.redhat.com/show_bug.cgi?id=451896,
> https://bugzilla.redhat.com/show_bug.cgi?id=454954, etc. This one is a
> regular PC working as a server in a cool server room, just arrived about a
> week ago. 2CPUs, 4G of RAM, 2 HDs in software RAID1, nothing special.
> Kernel 2.6.32-220.23.1.el6.x86_64 (RedHat).
>
> I understand it may be a BIOS issue with ACPI implementation, or it may be
> a kernel bug (though I'd expect those to be sorted out by now, given that
> the general issue is old). I have not yet tinkered with the BIOS or the
> kernel (may do it on Sunday when customers sleep), but I am vaguely
> concerned that if I manage to switch ACPI off in the BIOS I may miss real
> overheating (of which this may be a symptom - ?).
>
>
Nothing helped - upgraded the kernel (well, not much, to 2.6.32-279), tried
to boot with "acpi_osi=", tinkered with BIOS power settings (disabled
everything), but the offending tasks disappeared from the top of top(1)
only after I did

echo disable > /sys/firmware/acpi/interrupts/gpe_all

As far as I understand the issue may be flaky HW or cable or something, but
I do not know what it is. I also do not understand completely what the
possible ramifications of the above action may be. So far I added the above
command to /etc/rc.local.

If anyone has any insights, do let me know.

-- 
Oleg Goldshmidt | oleg at goldshmidt.org
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.cs.huji.ac.il/pipermail/linux-il/attachments/20120722/b2313a8f/attachment-0001.html>