panic: recursive fpu_kern_enter while in PCB_FPUNOSAVE state                                                                                    
cpuid = 26                                                                              
time = 1602697522                                                                       
KDB: stack backtrace:                                                                   
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xffffffff827848a0          
vpanic() at vpanic+0x182/frame 0xffffffff827848f0                                       
panic() at panic+0x43/frame 0xffffffff82784950                                          
fpu_kern_enter() at fpu_kern_enter+0x231/frame 0xffffffff82784980                       
fletcher_4_sse2_native() at fletcher_4_sse2_native+0xd2/frame 0xffffffff827849b0        
fletcher_4_native() at fletcher_4_native+0xeb/frame 0xffffffff82784ba0                  
fletcher_4_benchmark_impl() at fletcher_4_benchmark_impl+0xe0/frame 0xffffffff82784c40  
fletcher_4_init() at fletcher_4_init+0x1a7/frame 0xffffffff82784c60                     
mi_startup() at mi_startup+0xec/frame 0xffffffff82784cb0                                
btext() at btext+0x2c                                                                   
KDB: enter: panic                                                                       
[ thread pid 0 tid 100000 ]                                                             
Stopped at      kdb_enter+0x37: movq    $0,0x10ad516(%rip)