LOR seen on 13.x kernel

Hi All,
Seeing the below LOR in the 13.x kernel, is this a known issue ?
Could this cause vnode to max out and slow down the system.
Is there a patch available?(or can we ignore this ?)

kernel: Waiting (max 60 seconds) for system process `vnlru' to stop...done

kernel: Waiting (max 60 seconds) for system process `bufdaemon' to
stop...done

kernel: Waiting (max 60 seconds) for system process `syncer' to stop...

kernel: Syncing disks, vnodes remaining...114 lock order reversal:

kernel: 1st 0xfffff80003b26068 syncer (syncer) @ kern/vfs_subr.c:1853

kernel: 2nd 0xfffff800038902d8 devfs (devfs) @ ufs/ffs/ffs_vfsops.c:1632

kernel: KDB: stack backtrace:

kernel: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0x
fffffe022f899630

kernel: witness_checkorder() at witness_checkorder+0xc87/frame 0x
fffffe022f8996c0

kernel: __lockmgr_args() at __lockmgr_args+0x745/frame 0xfffffe022f8997f0

kernel: vop_stdlock() at vop_stdlock+0x3c/frame 0xfffffe022f899810

kernel: VOP_LOCK1_APV() at VOP_LOCK1_APV+0xab/frame 0xfffffe022f899840

kernel: _vn_lock() at _vn_lock+0x43/frame 0xfffffe022f8998a0

kernel: ffs_sync() at ffs_sync+0x2f9/frame 0xfffffe022f899970

kernel: sync_fsync() at sync_fsync+0xfa/frame 0xfffffe022f8999b0

kernel: VOP_FSYNC_APV() at VOP_FSYNC_APV+0xc4/frame 0xfffffe022f8999e0

kernel: sched_sync() at sched_sync+0x338/frame 0xfffffe022f899a70

kernel: fork_exit() at fork_exit+0x71/frame 0xfffffe022f899ab0

kernel: fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe022f899ab0

Regards
Arun