The performance management unit (PMU) is a component of modern CPUs that provides insight into the operation of the processor by counting specific hardware events. The PMU is widely used for statistical profiling (for performance analysis at the microarchitecture level) but also for production use, such as driving models of energy use that are essential for managing overall energy consumption in a computer system.

The seL4 microkernel presently only supports the PMU in a debugging configuration, which is sufficient for profiling but not for production use. A recent RFC proposes the introduction of a new PMU kernel object to support these use cases. This project is to implement and evaluate the PMU object in seL4 and its use for sharing and time-multiplexing the PMU.


Computer Science and Engineering

Research Area

Operating systems

The Trustworthy Systems (TS) Group is the pioneer in formal (mathematical) correctness and security proofs of computer systems software. Its formally verified seL4 microkernel, now backed by the seL4 Foundation, is deployed in real-world systems ranging from defence systems via medical devices, autonomous cars to critical infrastructure. The group's vision is to make verified software the standard for security- and safety-critical systems. Core to this a focus on performance as well as making software verification more scalable and less expensive.

  1. Prototype implementation of a PMU object in seL4;
  2. Demonstration of its use for securely sharing the PMU between processes with different monitoring needs, including processes requiring a global view as well as processes observing their own performance;
  3. Report outlining findings.
Scientia Professor and John Lions Chair Gernot Heiser
Scientia Professor and John Lions Chair