(Illustration by Gaich Muramatsu)
On Sun, 26 Jul 1998, Shafeeq Sinnamohideen wrote: > On Sun, 26 Jul 1998, Jim Doyle wrote: > > What are the major feats of moving away from LWP's and to native > > threads? Ultimately, a proprietary user-space threads package > > is a liability IMHO - as we learned with DCE threads on FreeBSD. > > As Peter said, the main problem is that LWPs are by definition > cooperative, not preemptive, and all of Coda is written with that > assumption. Its main benefits are that thread switching is fast and > doesn't involve the kernel, and it provides just enough functionality for > what Coda needs. It would not be too hard to base LWP on top of, say, > pthreads, or something similar. The main benifits that I can see would be > portability and better I/O handling, especially wit a kernel ptherads > implementation. Also, the benefits of parallelism on an MP machine -- with increasing need for strong encryption (bye-bye to DES as an option as of last week), the servers may become more CPU-intensive. With true preemptive pthreads support, SMP pthreads support (such as in Solaris, and presumably other platforms such as Linux+*BSD) would be possible. This would be quite a bit of work, but the results would be quite good -- especially if in the future there are ports to Java, etc, where threads are more common-place than present-day UNIX. Robert N Watson Carnegie Mellon University http://www.cmu.edu/ TIS Labs at Network Associates, Inc. http://www.tis.com/ SafePort Network Services http://www.safeport.com/ robert@fledge.watson.org http://www.watson.org/~robert/Received on 1998-07-26 18:12:33