Am I way off base here?

Galen Sampson galen_sampson at yahoo.com
Tue Nov 25 16:36:45 PST 2003


Matthew Dillon wrote:
    Well, my behavior isn't much better when it gets into the flame domain :-)

    In anycase, the two implementations are not diametrically opposed but
    they are implemented differently.  My argument isn't really with the
    design choice, though I do feel that the IPC method is better.  My
    argument is with FreeBSD making that design choice but then not following
    through with the necessary static binary support to really make it work
    well, and then using that as an excuse to make root dynamic.  Sigh.
I have been reading these threads on current.  I did not get understand 
that was your arguement from what you posted there.  Your initial post 
starting this thread did not enlighten me either (which asks if there is 
something wrong with an IPC approach).  If your arguement was clear and 
I missed it then you should entertain the possiblity that other missed 
it as well.  Their reactions may have been strong since they may have 
heavily invested time and effort into something that they mistakenly 
think you are putting down that work.

I have not seen a well thought out, convincing, argument for or against 
a dynamic root.  I also don't pretend to know enough about the 
implications of each to weigh them.  Therefore I am in the position to 
rely on those who do (I would say that you know far more then I on the 
subject, but so must others on the core team of FreeBSD).  That said 
your ideas so far (lwkt_thread/lwkt_msg) seem to be good ones.  I have 
no reason to think that an IPC NSS will "not work" unless we are not 
capable of making it work sucessfully.  Actually I like that the ideas 
in dragonfly have not necessarily been done before (just as I liked to 
read the papers about the MIT exokernel, and K42).  Things can't 
necessarily be proven correct or incorrect without trying out the idea 
(of course even then nothing is necessarily proven).  Here we seem to be 
"trying out" an IPC NSS.  We are in the middle of trying out lwkt_*. 
Whether lwkt_* is better or worse than anyone else's ideas doesn't 
necessarily concern me.  It can just be redone/improved to make it 
better.  The same applies to the IPC NSS idea.  In short this is not a 
contest to me, more of an exploration.

I did not consider any other alternative to NSS then to have a fully 
dynamic system.  The fact that there is an alternative, and that you 
voiced it, is a very good thing (it seems that some people 
miss-interpreted your discussion of that idea, and thats too bad).  The 
fact that you are implementing it is even better.  It is clear that many 
people want NSS.  It is also clear that some people want a static root. 
 Thus the problem becomes "how can we have a static root with support 
for NSS".  It seems that a large portion of the threads on -current seem 
to be saying "I want it this way!" without providing a workable solution 
to "the problem".  Your idea was possibly the only solution posted to 
the -current list that solves this problem.

I have been tempted to try to mediate current.  If I owned a "heavy 
stick" (was respected enough to have my voice heard) I would propose 
those that want a static root to gather their pros for this 
implementation (including benchmarks, etc.).  I would also propose those 
that want a dynamic root to provide their pros.  The benchmarks would be 
run by everyone.  I would also accept alternative solutions (of which 
your IPC is one, and dlopen() for static binaries is another).  Then a 
reasonable discussion could be started with all information at hand. 
Hopefully a workable compromise could be made.

Note that this supposedly happened earlier but was more or a private 
discussion between the developers.  The significance of it was obviously 
not noticed.  However as I noted above, they are the people in a better 
position to outline their arguments, as I do not know enough.

Of course I don't have the "big stick".  I doubt I posess the political 
intelligence to not piss people off.  I would also be adding to 
something that is out of hand, probably to be drowned out.

Pesonally it is really sad to see such a small thing (apparently it 
isn't that small?) as this leave a bad taste in the mouths of many 
obviously talented people (You + PHK + Scott Long + FreeBSD 
core/developers).  It seems to me that FreeBSD is good, and has the 
potential to be great.  Things like this only hurt it.

Regards,
Galen





More information about the Kernel mailing list