157k interrupts per second causing 60% CPU load on idle system

Matt Thyer matt.thyer at gmail.com
Thu Mar 22 14:33:49 UTC 2012

On Mar 22, 2012 10:14 AM, "Mike Tancsa" <mike at sentex.net> wrote:
> On 3/20/2012 1:26 AM, Matt Thyer wrote:
> > I've upgraded my FreeBSD-STABLE NAS from r225723 (22nd Sept 2011) to
> > r232477 (4th Mar 2012) and am finding that a system process called
> > is now constantly using about 60% of 1 CPU starting a short time after
> > reboot (possibly triggered by use of the samba server).
> >
> > When this starts, systat -vm 1 says that the system is 85% idle and 14%
> > interrupt handling.
> > It says that there's around 157k interrupts per second.
> >
> > Any idea what could be the cause ?
> This sounds like the problem I had with my intel board.  BIOS update
> fixed it.  What chipset and MB vendor do you have ?

The original post tells you this.
I've already updated to the latest BIOS and this could have caused the

I think I should try updating the firmware of the SAS/SATA HBA but not
until I've confirmed if a BIOS downgrade works.

Unfortunately it's very hard to get downtime on this system so it may be
some time before I can report any news.

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