Fwd: Interrupt Overload

[Dutch Ingraham]

Hi everyone - I am resending this as it is not appearing in the archives
so I don't believe it made it to the general list-serv. (My apologies if
it actually did make it.)

-------- Original Message --------
Subject: Interrupt Overload
Date: Sat, 31 May 2014 15:57:38 -0400
From: Dutch Ingraham <stoa at gmx.us>
To: freebsd-hackers at freebsd.org

Hi all:

I hope someone here can help.  I've tried the general community but no
resolution was found.  See "forums dot freebsd dot org slash
viewtopic.php?f=3&t=46595".

The problem is insanely high interrupts *only* while using xorg-server.
 For example, <systat -vmstat> or <vmstat -i> indicates a constant rate
of 325000 to 326000 interrupts from irq16: uhci0.  This is consuming
about 30% of my cpu usage.  All is normal in the TTY before starting X.
 The only usb devices attached are a mouse and keyboard; swapping them
makes no difference; in fact, using a PS/2 keyboard or even detaching
both the keyboard and mouse has no effect.

The only thing I've found that works is suspending to RAM with the
command <acpiconf -s 3>; upon waking the interrupts drop to near zero.

My <uname -pr> is "10.0-STABLE amd64."

Thanks for any information you can provide.