I like this. There is strength in having many different species of operating system. Monocultures are vulnerable to all kinds of diseases, one way to combat that is to have a (much) larger variety of operating systems so that infecting any of them has a very low return-on-investment.
So any new operating system that is far from the beaten path should be very much welcomed, this one is more interesting than most since it is written using a high level language.
>So any new operating system that is far from the beaten path should be very much welcomed, this one is more interesting than most since it is written using a high level language.
I agree. But let's keep in mind that this isn't the first OS kernel written in Common Lisp.
Begs the question: is it possible to write a Lisp-based escape from the Lisp VM to the Virtualbox VM, then an escape from the Virtualbox VM to the host OS? Perhaps, but not something a casual attacker is likely to have resources for ;)
The idea of a VM is that it provides an iron box which nothing can break out of, because it's completely invisible. There's nothing a guest can do which could possibly distinguish a VM session from running on the bare hardware. Partly this is for compatibility, partly for ease of development (develop the next VM as a guest in the current VM!), and partly for simple security: You can't escape a prison if you are utterly convinced you're already out.
Maybe that part of the theory never made it into practice.
The idea of a VM is that it provides an iron box which nothing can break out of, because it's completely invisible. There's nothing a guest can do which could possibly distinguish a VM session from running on the bare hardware. Partly this is for compatibility, partly for ease of development (develop the next VM as a guest in the current VM!), and partly for simple security: You can't escape a prison if you are utterly convinced you're already out.
Maybe that part of the theory never made it into practice.
Have you ran the OS and seen this actual issue you're describing? If not, then what's your problem? If you're going to armchair quarterback, you should at least have thrown a football a few times first.
You may as well be complaining that the Windows 1.0 press release from 1985 has trouble with multitasking. Duh, this is pre-alpha software we're looking at.
This is true of any dynamic memory management unless very careful constraints are put in place. I would assume anyone writing an OS kernel, regardless of language, would be careful to avoid unbounded consing. (Of course, memory allocation in kernels is tricky even in C: http://lwn.net/Articles/627419/)
The "garbage velocity" is not the most important parameter. Remember that garbage is all the space which remains after we identify what is reachable. The traversal of the graph of what is reachable is mainly where the performance pitfalls lie. When garbage is generated at a high rate, it just means that collection has to be more frequent. However, real-time techniques avoid scanning the entire graph of everything that is reachable.
Under ephemeral garbage collection, if the software generates a lot of garbage fast, it means that it's rapidly making large numbers of "baby" objects (objects in the "nursery" or "generation 0") and immediately losing them. Whenever a generation pass comes along, there are hardly any nursery objects to visit (they almost all been lost due to the "garbage velocity"), and the tenured objects aren't traversed either, so ... it's quick. Quick isn't "free", but it's not "beyond the ability to cope".
Jon pls, do you even Lisp Machine? Seriously, you can't base your opinion on kernels/OS:s written in Lisp on this guy's hobby project. I know what you think of GC, but history shows what an industrial Lisp OS is like and it's awesome.
So any new operating system that is far from the beaten path should be very much welcomed, this one is more interesting than most since it is written using a high level language.
Looking forward to an eventual release.