12.0-BETA3 isp(4): exclusive sleep mutex CAM device lock (CAM device lock)

[Harry Schmalzbauer]

Hello,

unnfortunately I can't determine if this is begnin, so I'd like to ask 
the experts:

uma_zalloc_arg: zone "64" with the following non-sleepable locks held:
exclusive sleep mutex CAM device lock (CAM device lock) r = 0 
(0xfffff8000f1424d0) locked @ 
/usr/local/share/deploy-tools/RELENG_12/src/sys/cam/cam_xpt.c:4309
stack backtrace:
#0 0xffffffff8060ead3 at witness_debugger+0x73
#1 0xffffffff8060fa48 at witness_warn+0x448
#2 0xffffffff808b6f18 at uma_zalloc_arg+0x38
#3 0xffffffff8058773a at malloc+0x9a
#4 0xffffffff8036f423 at nvlist_create+0x23
#5 0xffffffff8030d597 at ctl_port_register+0x187
#6 0xffffffff8031aa25 at ctlfeasync+0x405
#7 0xffffffff802ca772 at xpt_async_process_dev+0x162
#8 0xffffffff802c603d at xpt_async_process+0x15d
#9 0xffffffff802c697e at xpt_done_process+0x35e
#10 0xffffffff802c8a76 at xpt_done_td+0xf6
#11 0xffffffff8056e094 at fork_exit+0x84
#12 0xffffffff808f46de at fork_trampoline+0xe
uma_zalloc_arg: zone "64" with the following non-sleepable locks held:
exclusive sleep mutex CAM device lock (CAM device lock) r = 0 
(0xfffff8000f1414d0) locked @ 
/usr/local/share/deploy-tools/RELENG_12/src/sys/cam/cam_xpt.c:4309
stack backtrace:
#0 0xffffffff8060ead3 at witness_debugger+0x73
#1 0xffffffff8060fa48 at witness_warn+0x448
#2 0xffffffff808b6f18 at uma_zalloc_arg+0x38
#3 0xffffffff8058773a at malloc+0x9a
#4 0xffffffff8036f423 at nvlist_create+0x23
#5 0xffffffff8030d597 at ctl_port_register+0x187
#6 0xffffffff8031aa25 at ctlfeasync+0x405
#7 0xffffffff802ca772 at xpt_async_process_dev+0x162
#8 0xffffffff802c603d at xpt_async_process+0x15d
#9 0xffffffff802c697e at xpt_done_process+0x35e
#10 0xffffffff802c8a76 at xpt_done_td+0xf6
#11 0xffffffff8056e094 at fork_exit+0x84
#12 0xffffffff808f46de at fork_trampoline+0xe

Thanks for hints,

-harry