The Performance Cost To SELinux On Fedora 31

As you can see from this look at all of the results with a measurable performance difference, there can be quite an impact in some workloads. Having the greatest impact though were synthetic benchmarks like Schbench and Hackbench for stressing the Linux kernel's scheduler. OSBench for the time to create files also saw big performance hits. But there were real-world workloads with a sizable difference like Apache HTTPD, Memcached, and others.

The gaming performance impact tended to be very small in relation to the security benefits provided by SELinux.

For most scientific workloads or those strictly running in user-space and CPU bound, there wasn't much of a difference either.