syzbot

panic: sched_pickcpu: Failed to find a cpu.
cpuid = 0
time = 1
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xffffffff82e047a0
vpanic() at vpanic+0x1e0/frame 0xffffffff82e04800
panic() at panic+0x43/frame 0xffffffff82e04860
sched_pickcpu() at sched_pickcpu+0x8b9/frame 0xffffffff82e04950
sched_add() at sched_add+0xaa/frame 0xffffffff82e04990
gtaskqueue_start_threads() at gtaskqueue_start_threads+0x144/frame 0xffffffff82e04a30
taskqgroup_cpu_create() at taskqgroup_cpu_create+0x14e/frame 0xffffffff82e04a70
taskqgroup_adjust() at taskqgroup_adjust+0x256/frame 0xffffffff82e04b00
mi_startup() at mi_startup+0x3ec/frame 0xffffffff82e04b70
btext() at btext+0x2c
KDB: enter: panic
[ thread pid 0 tid 100000 ]
Stopped at      kdb_enter+0x6a: movq    $0,kdb_why
db>