About me

Hi, I’m John Alistair Kressel, a final year PhD student at the University of Manchester. My advisors are Pierre Olivier and Hugo Lefeuvre. My research explores the intersection of single-address-space systems and OSes and systems security. I focus on fundamental system design, specifically investigating novel mechanims and efficient compartmentalization strategies within single address spaces. You can find my list of publications here.

Latest Research

μFork (Published at SOSP'25)

μFork enables Single-Address-Space Operating Systems (SASOS) to support multi-process applications using the POSIX fork() primitive without sacrificing performance. It achieves this by duplicating a parent process’s memory to a new location within the same address space, rather than creating a separate address space as traditional.

To make this feasible and secure, μFork leverages CHERI hardware capabilities two solve memory reference relocation and inter-process isolation.

We show that μFork is able to outperform traditional monolithic OSes on metrics such as fork latency by an order of magnitude. Find the paper here.

MicrOS (Ongoing)

I am currently porting noMMU Linux to the RISC-V CHERI Codasip X730 platform. The goal of this project is to ask “what if we remove the MMU?” - can features which rely on the MMU such as paging and copy-on-write be efficiently supported allowing the overhead and indeterminacy of the MMU to be eliminated from the critical path.

Skills & Experience

I have deep experience developing and debugging kernels including Linux, on ARM and RISC-V architectures. I am comfortable debugging bare-metal and at the assembly level. Further, I have designed and implemented userspace and kernel compartmentalization using mechanisms such as CHERI and Intel MPK.

News

[10/2025] Our paper on μFork has been published at SOSP’25! Find the paper here.

Contact

If you’d like to reach out and chat about my research, my email is john.kressel (at) manchester.ac.uk