# echo c >/proc/sysrq-trigger

# cat /proc/sys/kernel/panic
0    <- The 0 is  reboot after 0 second.

or

# sysctl kernel.panic
0

# vi /etc/sysctl.conf
kernel.panic = 30    <- reboot after 30 seconds

# sysctl -p

# sysctl kernel.panic   <- check

linux#kernle