=== DF-2729 decisive run (serial console, vm.sh log) ===
login: df2728: loaded on cpu0, target cpu1, td1=0xfffff800905fc100 td2=0xfffff800905fc780
df2728: mode2(DF-2729): TDF_MIGRATING window + lwkt_schedule(td2=0xfffff800905fc780) cpu0 -> cpu1
panic: assertion "(td->td_flags & TDF_MIGRATING) == 0" failed in _lwkt_schedule at /usr/src/sys/kern/lwkt_thread.c:1293
cpuid = 0
Trace beginning at frame 0xfffff80118465748
lwkt_schedule() at lwkt_schedule+0x2d9 0xffffffff806743b9 
lwkt_schedule() at lwkt_schedule+0x2d9 0xffffffff806743b9 
df2728_mode_sysctl() at df2728_mode_sysctl+0x11b 0xffffffff8260011b 
sysctl_root.isra.5() at sysctl_root.isra.5+0x166 0xffffffff80683d06 
userland_sysctl() at userland_sysctl+0x111 0xffffffff806840a1 
sys___sysctl() at sys___sysctl+0x74 0xffffffff80684204 
Debugger("panic")

CPU0 stopping CPUs: 0x0000003e
 stopped
Stopped at      Debugger+0x7c:  movb    $0,0xbdaf09(%rip)
db>