On Tue, 09 Oct 2018 10:45:37 -0700 Lyndon Nerenberg <lyn...@orthanc.ca> wrote: Lyndon Nerenberg writes: > Bakul Shah writes: > > > One thing I have mused about is recasting plan9 as a > > microkernel and pushing out a lot of its kernel code into user > > mode code. It is already half way there -- it is basically a > > mux for 9p calls, low level device drivers, VM support & some > > process related code. > > Somewhat related to this ... after reading some papers on > TCP-in-user-space implementations, I've been thinking about how an > interface that supported fast/secure page flipping between the > kernel and process address space would change how we do things. > > E.g. right now Plan 9 suffers from a *lot* of data copying between > the kernel and processes, and between processes themselves. If we > could eliminate most of that copying, things would get a lot faster. > Dealing with the security issues isn't trivial, but the programmer > time going into eeking out the last bit of I/O throughput of the > current scheme could be redirected.
Funny you say this. I wrote I wanted memory mapping to avoid having to copy data multiple times but then deleted it, thinking it would detract from the main point. Actually I want this even without any major redesign! > If it works, this would reduce the kernel back to handling > process/memory management, and talking to the hardware. Not a > micro-kernel, but just as good from a practical standpoint. Some of this process/memory management can be delegated to user code as well.
