"In upstream development news, the kernel team here at Red Hat has been working on a dynamic kernel patching project called kpatch for several months. At long last, the project has reached a point where we feel it’s ready for a wider audience and are very excited to announce that we’ve released the kpatch code under GPLv2.
"kpatch allows you to patch a Linux kernel without rebooting or restarting any processes. This enables sysadmins to apply critical security patches to the kernel immediately, without having to wait for long-running tasks to complete, users to log off, or scheduled reboot windows. It gives more control over uptime without sacrificing security or stability."
Read the whole article here: Introducing kpatch: Dynamic Kernel Patching | Red Hat Enterprise Linux Blog.