(Illustration by Gaich Muramatsu)
Coda was originally written on top of Mach 2.6 which did indeed have kernel threads. However, early experiments showed the kernel threads to have serious overhead (Re: an IEEE Trans on Computers paper from April '90). Kernel threads would be a big win, especially the ability to overlap disk I/O and other processing (currently things block. We do handle network I/O properly). Peter, have you guys implemented cells? If not, have you played with running multiple venii (to have different, concurrent, non-overlapping name spaces?) Thanks, david. Was Re: coda 4.3.13 on RHL 5.0 + egcs 1.0.1 At 10:21 PM 2/3/98 -0500, you wrote: >On Tue, 3 Feb 1998, Jim Doyle wrote: >> You guys are doing user-space threads on Linux ?? I had a quick look at >> the LWP library in Coda. > >Yes, for historical reasons. The coda code has roots in the mid-80s, >before the widespread availability of threads on Unix. There is/was some >support for kernel threads on Mach in some parts of Coda, I think, but I >don't know if that code has run recently. > >Unfortunately, the Coda code may rely on the non-preemptive nature of the >user-level thread implementation. > >RVM _is_ supposed to be really thread-safe, and one big win would be to >let the RVM log compaction run in parallel with the other (nonpreemptive) >threads. > >A good project for someone, perhaps... > >Michael > > >Received on 1998-03-24 13:18:12