ixgbe(4) spin lock held too long

[John Baldwin]

On Monday, September 08, 2014 03:34:02 PM Eric van Gyzen wrote:
> On 09/08/2014 15:19, Sean Bruno wrote:
> > On Mon, 2014-09-08 at 12:09 -0700, Sean Bruno wrote:
> >> This sort of looks like the hardware failed to respond to us in time?
> >> Too busy?
> >> 
> >> sean
> > 
> > This seems to be affecting my 10/stable machines from 15Aug2014.
> > 
> > Not a lot of churn in the code so I don't think this is new.  The
> > afflicted machines, quite a few by my count, appear to have not been
> > super busy (pushing about 200 Mb/s).
> > 
> > sean
> > 
> >> panic: spin lock held too long
> >> 
> >> GNU gdb 6.1.1 [FreeBSD]
> >> Copyright 2004 Free Software Foundation, Inc.
> >> GDB is free software, covered by the GNU General Public License, and you
> >> are
> >> welcome to change it and/or distribute copies of it under certain
> >> conditions.
> >> Type "show copying" to see the conditions.
> >> There is absolutely no warranty for GDB.  Type "show warranty" for
> >> details.
> >> This GDB was configured as "amd64-marcel-freebsd"...
> >> 
> >> Unread portion of the kernel message buffer:
> >> spin lock 0xffffffff812a0400 (callout) held by 0xfffff800151fe000 (tid
> >> 100003) too long
> 
> TID 100003 is usually a kernel idle thread, which would seem to indicate
> a dangling lock.  Can you enable WITNESS (without WITNESS_SKIPSPIN) on
> this box?

Also, do 'tid 100003' and 'bt' in kgdb to see what the thread holding the lock 
was doing.

-- 
John Baldwin