[SunRescue] OT: dual PPro mb's...

[Joshua D. Boyd]

That's too bad.  They don't mention anything to that effect on their (SGI)
linux scalability project page.  On a related note, I tried to get the
dmSDK to work, but found the documentation to be rather frustrating.
Hopefully they will do better with the documentation for other projects.

--
Joshua Boyd

On Fri, 30 Mar 2001, Chris Byrne wrote:

> Unfortunately due to lack of cooperation and interest in the core kernel
> team SGI has stopped activley contributing large scale SMP code to the Linux
> kernel. They are still releasing it on their own as a custom kernel patch at
> this point however.
> 
> IBM also had the same problems when they wantd to do large scale SMP.
> Apparently Linus response was that he didnt think that Linux should go there
> yet, because it wasn't ready, so they werent going to make it a priority.
> 
> Chris Byrne
> 
> -----Original Message-----
> From: rescue-admin at sunhelp.org [mailto:rescue-admin at sunhelp.org]On
> Behalf Of Joshua D. Boyd
> Sent: Friday, March 30, 2001 13:10
> To: rescue at sunhelp.org
> Subject: Re: [SunRescue] OT: dual PPro mb's...
> 
> 
> On Fri, 30 Mar 2001, Greg A. Woods wrote:
> 
> > Rumour has it (I'm not a Linux user) even the 2.4 kernel has far
> > "grainier" data structure locking for SMP than would be desirable for
> > really good CPU utilisation.  I'm not sure how many CPUs it's designed
> > to handle well either.  IIRC Linus said something about the locking
> > being a little more coarse than he'd like in his rushed announcement of
> > the 2.4 kernel.
> 
> Well, I was under the impression that Linus' comments were to be
> interpreted as meaning that it was fine for 2way SMP, but not as good as
> possible on 4, 8, or 16 way SMP.  SGI has a team working on tuning linux
> for 32 and more CPU machines BTW.  They are working ontop of origin 2000
> machines last I heard.  Most of the changes they make should also benefit
> Intel users.
> 
> I can't really comment too much on network performance though since that
> isn't my area of specialty.  Heck, I'm still running 10mbit everywhere in
> my house rather than 100mbit.  I can tell you that dual processors get
> twice the performance on kernel compiles.  I've also found that some
> programs (like WindowMaker) can't be compiled using the -j2 flag.  Bummer.
> I don't realy have anything else that would push my CPUs.  I haven't had
> time to work on any threaded stuff since I got the machine running linux
> (for the first few monthes of owning it, it ran windows to play DVDs).
> 
> --
> Joshua Boyd
> 
> 
> >
> > (I really don't know what the problem is -- the Bell Labs folks did a
> > dual-CPU implementation of V7 way back in the early 80's and there have
> > been lots of people doing it even better ever since and many of them
> > have documented their methods and the various tricks and traps they've
> > encountered along the way.  I.e. the knowledge is out there and it
> > should be trivial enough to apply it, especially in Linux where the main
> > target still seems to be the Intel processor family.  It should merely
> > be a matter of engineering at this point.  The NetBSD folks have been
> > doing a "clean" implementation and it'll probably pull up into the
> > public source in the next few months, and it's supposed to have fully
> > N-way CPU support and completely hardware independent.  I'll bet it gets
> > fine-grained locking far more quickly once it's public than any of the
> > other systems have apparently been managing.  That said though I've
> > heard very promising things from the FreeBSD folks, especially ever
> > since they joined forces with BSDi.)
> >
> > --
> > 							Greg A. Woods
> >
> > +1 416 218-0098      VE3TCP      <gwoods at acm.org>      <robohack!woods>
> > Planix, Inc. <woods at planix.com>; Secrets of the Weird <woods at weird.com>
> > _______________________________________________
> > rescue maillist  -  rescue at sunhelp.org
> > http://www.sunhelp.org/mailman/listinfo/rescue
> >
> 
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