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From: rich@oxtrap.UUCP (K. Richard Magill)
Newsgroups: comp.unix.wizards
Subject: Re: Information on BSD 4.[23] on two/multiple processor systems
Message-ID: <293@oxtrap.UUCP>
Date: Tue, 11-Aug-87 20:26:27 EDT
Article-I.D.: oxtrap.293
Posted: Tue Aug 11 20:26:27 1987
Date-Received: Fri, 14-Aug-87 04:45:22 EDT
References: <1112@elrond.CalComp.COM>
Reply-To: rich@oxtrap.UUCP (K. Richard Magill)
Organization: Oxford TP, Ann Arbor
Lines: 57
Keywords: BSD 4.[23] Multiple Processor Systems

Sequent Computer Systems of Beaverton Oregon makes a 32032 based box,
(2-30), based on 4.2 (+ some 4.3 hacks), with SysV calls hacked in if
you want them, (dual universe), shared memory, memory mapped disk
files, atomic lock memory, etc, etc.  This system is load balanced by
time slice.  And the system works slic (pun intended!).  I've been on
more versions of unix than I can remember right now and I usually find
2-10 bugs in the first week on a new system.  I've been on DYNIX now
for ~2 months with exactly one major complaint.  (tell you later, or
watch real soon on comp.sys.sequent).

Their new 4.3'ish os release is due out in days and they are in beta
test on a multiple '386 based system, (2-30).

My answers with regards to sequent DYNIX 2.1.1.

In article <1112@elrond.CalComp.COM> adb@elrond.UUCP writes:
>
>  ... any information on BSD 4.2 or 4.3 support of multiple CPU ...
>  systems. (More specifically a two CPU system such as a VAX 11/782 or 
>  VAX 8800.) The types of information we are most interested in are:
>    o To what extent is the 2nd processor utilized? (Is it a true 
>      multi-processor port in that the kernel and user processes can
>      run on either CPU, or is it the case that the kernel runs on one
>      and only one of the CPUs?) 

Symmetric.  ie, balanced by time slice.

>    o Are there any performance measures which compare a two processor
>      system vs. the single processor version? (Using the same kernel
>      source on a single processor system vs. a two processor system,
>      does the two processor version equal 1.3? 1.5? 1.7? 2.0!? times
>      a single processor system?)

All that I have seen and done are nearly linear, upt to about 27/30 on
a 30 cpu balance.

>    o Which systems DO have a dual (or multiple) CPU UN*X?

I know that encore offers a multiple 32032 based box but I don't know
much about it except that it is SysV'ish.  The new NCR broadway is a
bunch of 68020's that do load balance by process, (basically network
in a box, SysV + proprietary ipc), and the Convergent Technologies
systems use a proprietary operating system (CTOS), with a "unix
emulator" on top.  And then there is "the-network-is-the-computer"
SUN...

>    o What kind of theoretical/practical performance improvement benchmarks
>      does the 2 CPU system have over the single CPU version?

With the exception of locking which is seldom a problem, lock
overhead, which is noticable (check iocall results for sequent) but a
necessary evil, and process coordination, it is linear.

rich.

ps, oxtrap is a sequent B8000(6)
"lies keep people happy" - I94 west of detroit.