
SELinux introduces a new access control mechanism in the Linux kernel called
"mandatory access control". It has been in the mainline Linux kernel since 2003, and included in RedHat Enterprise Linux 4 (2005). RedHat have been testing SELinux for quite some time through the Fedora releases, where it has been available since Fedora 2 (2004). RedHat is aggressively pushing the development of SELinux and relevant tools forward. From RHEL version 4 to 5 the targeted policy includes more services, added support for a modular policy, (graphical) administrations tools and support for MLS. But what are the performance penalties when running with and without SELinux enabled?