Re: New brainfart for threaded VFS and data passing between threads.

[Max Okumoto <okumoto@home>]

Matthew Dillon wrote:
> :
> :Matthew Dillon wrote:
> :>     The recent PIPE work adapted from Alan Cox's work in FreeBSD-5 has really
> :>     lit a fire under my seat.  It's amazing how such a simple concept can
> :>     change the world as we know it :-)
> :
> :Out of curiousity, have you considered some of the ideas from exokernel
> :designs?
>
>     Not really.  As far as I can tell, all exokernel does to get its 
>     stated performance improvement is to vertically integrate everything,
>     e.g. such as the web server and TCP protocol stack, into what is
>     essentially a single execution context.
>
>     Well, I stopped doing that the day I set aside my Amiga for a PC running
>     Linux, and you won't see me going back.  I don't see how such a system
>     could ever be used in a complex production environment.... it would be
>     nearly impossible to track down and fix bugs.
>
>     I will be frank... I could integrate a TCP stack into a web server and
>     fast-path the most common connection/data/disconnect situations, but the
>     resulting mess would be unsupportable.  It might look good in a one-off
>     performance benchmark but the cost of trying to maintain such a beast
>     over time would be horrendous.  The last embedded hardware project I wrote
>     was based on a 10MHz 68000, and even the little UDP stack I wrote for
>     that was message-based and protected (via a simple protection map tacked
>     on to the memory subsystem) rather then vertically integrated.  So,
>     no, exokernel does not appeal to me at all.
>
> 					-Matt
> 					Matthew Dillon 
> 					<dillon@xxxxxxxxxxxxx>

Have you read any papers on 'container shipping'?  This sounds
alot like the stuff that a friend of mine did for his thesis.


http://www.cs.ucsd.edu/groups/csl/pubs/conf/sosp95.html

		Max Okumoto