Kernel data - First class citizens of the system

Kernel memory is a resource that must be managed care- fully in order to ensure the efficiency and availability of the system. The use of an inappropriate policy would lead to suboptimal performance and even make the sys- tem susceptible to denial of service attacks. In this paper, we argue that user-level managers, with their domain specific knowledge, can better manage the kernel memory consumption of their clients than a static in-kernel policy; and we present the kernel memory management scheme of seL4, where kernel memory is represented as named, first class objects which are cre- ated and managed by user-level managers according to a suitable policy. The scheme is flexible enough to ex- press a wide range of policies, and allows multiple poli- cies to coexist.