Weird system cpu usage

[Jeremy Chadwick]

On Wed, Mar 19, 2008 at 06:53:36PM +0100, Oliver Fromme wrote:
> Charlie Root <root at ha-web1.hockeyarena.net> wrote:
>  > root@[ha-web1 ~]# vmstat -i
>  > interrupt                          total       rate
>  > irq1: atkbd0                          12          0
>  > irq16: ohci0                           1          0
>  > irq17: ohci1 ohci3                     1          0
>  > irq18: ohci2 ohci4                     1          0
>  > irq20: em0                      86255835       1361
>  > irq22: em1 atapci0           18611379049     293795
> 
> Now that looks unusual indeed.  Do you get that rate
> on irq22 right after boot, before the services have
> started?  It looks like either hardware or driver
> problems.  Do you have polling enabled on em1?

Also, I believe there was a report from another user who saw similar
issues with em(4), and found that disabling MSI fixed the storm in
question.  I believe you can disable MSI/MSIX by placing the following
in /boot/loader.conf, then reboot:

hw.pci.enable_msi="0"
hw.pci.enable_msix="0"

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |