Does ACL on Linux impact performance

Question

We are planning to implement ACL on our Linux platform. Only one particular group is going to come under ACL. This group would have at the max 20 users. All of the restrictions would be at directory level (not at file name level) Would this show any impact on the server's performance/responsiveness?

Answer 1

The time complexity depends on the ACL For instance SELInux and AppArmor have more overhead than traditional file permissions. However, many secuirty systems in the linux kernel have a time complexity of O(1), which is lowest time complexity possible and it means that there is no additional overhead.

Answer 2

Not really, the overhead is insignificant. This is the case for ACL scehemes that are network based and those that are entirely local machine based.