The Linux kernel is flexible, and you can even modify the way it works on the fly by dynamically changing some of its parameters using sysctl command. Sysctl provides an interface that allows you to examine and change several hundred kernel parameters in Linux or BSD. Changes take effect immediately, and there’s even a way to make them persist after a reboot.sysctl is used to modify kernel parameters at runtime. The parameters available are those listed under /proc/sys/. Procfs is required for sysctl support in Linux. You can use sysctl to both read and write sysctl data.Many of the tunable performance items can be configured directly by the kernel. The command sysctl is used to view current kernel settings and adjust them.