panic: mtx_lock_spin: recursed on non-recursive mutex cnputs_mtx @ /usr/src/sys/kern/kern_cons.c:420 when running dump in ddb

Andriy Gapon avg at
Mon Aug 22 06:43:40 UTC 2011

on 22/08/2011 04:34 Garrett Cooper said the following:
> On Thu, Aug 18, 2011 at 5:55 PM, Garrett Cooper <yanegomi at> wrote:
>> Hi,
>>    Long story short, I was running a UP kernel on a netbook trying to
>> stimulate a crash and when I did dump, it would periodically fail
>> non-recursive mutex failure with the output shown below (I caught it
>> once, but the other times the dump failed).
>     This actually shows up when generating a panic via boot -v with
> WITNESS, so it's potentially a race condition on my laptop. Adding
> MTX_RECURSE to the mutex object didn't help things either.

You may want to try to reproduce this panic with the following patch:

Andriy Gapon

More information about the freebsd-current mailing list