[stable 9] panic on reboot: ipmi_wd_event()

[John Baldwin]

On Thursday, July 19, 2012 7:58:14 pm Sean Bruno wrote:
> Working on the Dell R420 today, got most of it working, even the
> broadcom ethernet cards!  However, I get the following when I reboot the
> system:
> 
> Syncing disks, vnodes remaining...4 Sleeping thread (tid 100107, pid 9)
> owns a non-sleepable lock
> KDB: stack backtrace of thread 100107:
> sched_switch() at sched_switch+0x19f
> mi_switch() at mi_switch+0x208
> sleepq_switch() at sleepq_switch+0xfc
> sleepq_wait() at sleepq_wait+0x4d
> _sleep() at _sleep+0x3f6
> ipmi_submit_driver_request() at ipmi_submit_driver_request+0x97
> ipmi_set_watchdog() at ipmi_set_watchdog+0xb1
> ipmi_wd_event() at ipmi_wd_event+0x8f
> kern_do_pat() at kern_do_pat+0x10f
> sched_sync() at sched_sync+0x1ea
> fork_exit() at fork_exit+0x135
> fork_trampoline() at fork_trampoline+0xe

Hmmm, the watchdog pat should probably happen without holding locks if 
possible.  This is related to the IPMI watchdog being special and wanting
to schedule a thread to work.

-- 
John Baldwin