[9fans] Any significant gotchas?

[9fans] Any significant gotchas?

[John S. Dyson]

As some of you'all *might* know, I like playing with
OSes...  Any major gotchas in a planned booting
of plan9 on my SMP box? :-).  (Dell Precision 620,
dual 866 Xeon, with 1GB.)

Over the last few years, I have been planning to do
a fully distributed kernel.  It seems that plan9 might
be the best, common, at least semi-free entry in the
market -- and I just don't have the energy to do a
whole effort myself.  Even though it isn't EXACTLY
what I have been planning, it seems to be a reasonable
alternate 'opinion' that I could adopt.

How do you like plan9 (primarily as an experimental,
education or even useful) tool?  I have been intriqued
by it, only primary worry so far would be scalability
and other such issues (from my outside viewpoint.)

Do you guys think that it would be worthwhile to invest
serious time on upgrading and improving the kernel for
large scale usage (on a per-cpu basis.)  Has it improved
alot over the last few years so that an effort isn't
even appropriate?  (I have NO need or desire for private
use of my work, and plan to donate everything back for
review and potential incorporation, as the powers that
be see fit.)

Thanks for your input, and I really look forward to playing
with and investigating this very interesting OS entry.  Hopefully,
I'll be booting Plan9 in the next day or so.  It does seem
that Plan9 has been slowly (and lately more quickly) taking
off, since the license has been made more favorable.  (Please,
no license advocacy, there are other places for that :-)).

John

Re: [9fans] Any significant gotchas?

[Nigel Roles]

> As some of you'all *might* know, I like playing with
> OSes...  Any major gotchas in a planned booting
> of plan9 on my SMP box? :-).  (Dell Precision 620,
> dual 866 Xeon, with 1GB.)
> 


THe usual gotchas are

1) video card
2) SCSI card

read the hardware compatibility list.

Re: [9fans] Any significant gotchas?

[John S. Dyson]

In article <396B1F62.24083.11FD481@localhost>,
	ngr@9fs.org (Nigel Roles) writes:
> 
> 
>> As some of you'all *might* know, I like playing with
>> OSes...  Any major gotchas in a planned booting
>> of plan9 on my SMP box? :-).  (Dell Precision 620,
>> dual 866 Xeon, with 1GB.)
>> 
> 
> 
> THe usual gotchas are
> 
> 1) video card
> 2) SCSI card
> 
> read the hardware compatibility list.
> 
Of course...  How is stability?  Is there opportunity for
significant improvements in the kernel?  If I choose to run
1000 (or 10000 or 20000) processes on a single machine (not
uncommon on some machines nowadays), will the kernel work well,
degrading smoothly?  If I might want to spend alot of time
working on the code, I'd like to know where you think that
the improvement opportunities are.  When I initially looked
at the code a few years ago, I was impressed with both the
simplicity, but also saw some scalability problems.  It was
really great to see code that hasn't already been obscured
with complexity.  From an immediate gratification standpoint,
this might be alot of fun for me.

It is well understood that relatively less used OSes
will often need more driver support than they already have.
So, I kind-of already knew of that issue.  Note also, there
are often Network Card driver issues -- some manus don't
always fully document their cards, and change PCI ids, thereby
confounding probe code.  This problem is common, and thankfully,
there are alot of source-available OS codes available to work
from.

Also, one sometimes finds that X86 SMP implementations, with
differing APIC layouts, confound kernel startup.  I am not
initially depending upon running SMP, but it would be interesting
to hear anecdotal reports.  If the silly thing doesn't boot up, on
my day-to-day OS development machine, I'll buy another machine with
no hesitation.  It might be a good idea anyway to buy a Plan9-only
machine for any initial work.  (For example, FreeBSD required that
I recompile the kernel so as to support the large number of INTRs
available on the Dell 620.  Things dont always work out of the
box, even on slightly more common OSen.)

I have a copy of the entire comp.os.plan9 for the last few months,
and am encouraged with the traffic level.

John

Re: [9fans] Any significant gotchas?

[jmk]

	>As some of you'all *might* know, I like playing with
	>OSes...  Any major gotchas in a planned booting
	>of plan9 on my SMP box? :-).  (Dell Precision 620,
	>dual 866 Xeon, with 1GB.)

Many BIOS/motherboard combos pay fast and loose with the Intel
Multiprocessor Specification and there's sometimes tweaking required
to find out where the interrupts are really routed to. If you have
a problem like that let me know and get a copy of the MPS table
(there's an Intel binary available to dump it under MS-DOS).

The only other gotcha is Plan 9 will currently only attempt to size
memory up to 768MB, you will need to add
	*maxmem=0x40000000
to plan9.ini to make it probe up to 1GB.

--jim

Re: [9fans] Any significant gotchas?

[John S. Dyson]

In article <200007111439.KAA25086@cse.psu.edu>,
	jmk@plan9.bell-labs.com writes:
>	>As some of you'all *might* know, I like playing with
>	>OSes...  Any major gotchas in a planned booting
>	>of plan9 on my SMP box? :-).  (Dell Precision 620,
>	>dual 866 Xeon, with 1GB.)
> 
> Many BIOS/motherboard combos pay fast and loose with the Intel
> Multiprocessor Specification and there's sometimes tweaking required
> to find out where the interrupts are really routed to. If you have
> a problem like that let me know and get a copy of the MPS table
> (there's an Intel binary available to dump it under MS-DOS).
> 
> The only other gotcha is Plan 9 will currently only attempt to size
> memory up to 768MB, you will need to add
> 	*maxmem=0x40000000
> to plan9.ini to make it probe up to 1GB.
> 
Thanks!!!  When I get ready, and if I get some stuff working,
I'll also let you know.  I have the mptable program for FreeBSD
(I had to modify the FreeBSD config so that the Dell would work,
 it has more INTRs than FreeBSD normally configures), it provides
the (sometimes interesting) mapping info also!!!

John