panic: Most recently used by tty

cpuid = 1
time = 297
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0016bf73e0
vpanic() at vpanic+0x1e0/frame 0xfffffe0016bf7440
panic() at panic+0x43/frame 0xfffffe0016bf74a0
mtrash_fini() at mtrash_fini+0xeb/frame 0xfffffe0016bf74e0
keg_free_slab() at keg_free_slab+0x1a8/frame 0xfffffe0016bf7550
zone_drain_wait() at zone_drain_wait+0x37d/frame 0xfffffe0016bf75b0
uma_reclaim_locked() at uma_reclaim_locked+0x9f2/frame 0xfffffe0016bf7620
uma_reclaim() at uma_reclaim+0x2a/frame 0xfffffe0016bf7630
vm_pageout_worker() at vm_pageout_worker+0x52b/frame 0xfffffe0016bf7a20
vm_pageout() at vm_pageout+0x1fe/frame 0xfffffe0016bf7a60
fork_exit() at fork_exit+0xb0/frame 0xfffffe0016bf7ab0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0016bf7ab0
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 17 tid 100061 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why