I’ve seen this video of Timothy Roscoe at USENIX ATC '21 recently and was very interested in multikernel OSes.
While Barrelfish is abandoned, it seems that Kirsch is his successor.
However, since I’ve seen this video I wonder what changed since the keynote, why it doesn’t seem to be a thing for mainstream kernels and if there was any roadmap/will to expand mainstream kernels like linux to embrace the whole hardware.
Do you have any pointers/ideas or resources to share on this?
To answer your post title question, I suspect that at this point it seems counterintuitive to introduce complexity in an environment already rife with exploits.
It’s not like it’s a new idea either. Microsoft published research on this in 2009, 16 years ago.
https://www.microsoft.com/en-us/research/publication/the-multikernel-a-new-os-architecture-for-scalable-multicore-systems/
The abstract on that link holds the promise of many benefits, but it appears to carefully avoid specific claims, which makes me wonder if the idea ran into unexpected hurdles, which is common in software development.
The abandonment of the Barrelfish project is probably an indicator that this is an idea that didn’t pan out.
Having said that, I haven’t dug into kernel development over the past 40 years of my career, so it might well be that aspects and nuances of this idea were adopted and are in common use.