[ILUG] don't ya just hate it when...

[Paul Jakma]

On Thu, 17 May 2001, Smelly Pooh wrote:

> Anyway Unix is far from sun's 'network is the computer' slogan,
> surely your OS would need to be distributed to boast that.

on a serious note...

yes it would be i guess. although unix gets as close to it as possible
while still remaining a bunch of distinct computers.. plan9 is
supposed to distributed - anyone tried it?

there's also mosix which apparently makes a bunch of linux computers
act like one in terms of transparent process migration for load
balancing. Could be fun "right... who's gone and started StarOffice!".

there was an idea larry mcvoy posted on l-k a long time. his argument
was single image MP systems are bad, and just get exponentially worse
as they number of processors for which the OS image is designed to
scale to increases.

so his idea was that linux should absolutely not go down the IRIX,
SunOS path of increasingly bloated and lock heavy kernels in order to
support large MP systems. Instead, you should run a single OS image on
each node of the MP system and then come up with a scheme so that
images on different nodes can reserve/release resources from each
other. eg an "smpfs" distributed across the different nodes, with say
/node1/mem and nodeX could lock a region of node1/mem to indicate it
was using it.. etc.. the logic being you don't need to share an entire
kernel image between all the nodes, just arbitrate for resources
between nodes, so come up with a contained means to do the arbitration
and run multiple smaller less complicated kernels rather than
complicating and slowing down your kernel down with locks to make a
singe image fs.

So in effect with this scheme a large hardware coherent NUMA machine
would essentially be X seperate linux kernels (X=# of nodes) running a
distributed smpfs to coordinate access to memory, IO, inodes, etc..

Now imagine one day someone actually implements such a thing for
linux. The only difference between such a machine and a bunch of PCs
would be the hardware memory access...

just one more step of someone writing code to implement the NUMA stuff
over, eg ethernet or UDP. And hey presto... distributed linux will be
born.

would be funky..

--paulj