SMP problem on UP2000+

[John Baldwin]

On Monday 13 February 2006 12:26, Douglas K. Rand wrote:
> I have a UP2000+ system from Microway with two 833 MHz CPUs, and it
> keeps freezing up on me when I run it with a SMP kernel. The hangs
> always seem to come at times of high disk IO, such as nightly backups
> or heavy MySQL usage or buildworlds. (The system does my cacti
> resource graphing.)  I've got a debug kernel installed, but I can
> never break into the kernel nor do I ever get a core dump. I've
> experienced this problem with both 6.0 and 6_RELENG.
>
> I'm coming up on 4 days of uptime with a kernel that doesn't have SMP
> which is easily four times that of a kernel with SMP.
>
> I was running a gmirror of two 75 GB SCSI disks on the onboard
> controller, and to simply see if it was a factor I destroyed the
> mirror and am now only using one disk. I had hangs both with and with
> gmirror.
>
> Here are the messgaes I get on the console, when I get them. Sometimes
> the system simply hangs.
>
> panic: lockmgr: thread 0xfffffc007d9c4d20, not exclusive lock holder
> 0xfffffc007d9d5260 unlocking cpuid = 1

Have you tried disabling debug.mpsafevfs?  Set it to 0 in the loader.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org