[comp.arch] General purpose commercial multiprocessor systems without shared-memory

bwong@ihwpt.ATT.COM (bruce wong) (05/19/88)

Do general purpose commercial multiprocessor systems *without* shared-memory
exist ?

I know there are "general purpose" shared-memory machines like:

	recent VAXen
	recent Crays
	Sequents

I know there are "application specific" non-shared-memory machines like:

	hypercubes
	the Connection Machine
	Transputer arrays

Are there any general purpose non-shared-memory machines out there ?

I heard that DEC has a version of its OS that hides the multiprocessor
nature of its new machines; that is, you can treat them like bigger
uniprocessor machines.
Are there non-shared-memory machines with such an OS ?

Please EMAIL all replys.  I will post a summary at a future time.
-- 
	Bruce F. Wong	1A-111		312-416-5111
	ATT Bell Laboratories		ihnp4!ihwpt!bwong
	200 Park Plaza
	Naperville, Ill 60566-7050

bwong@ihwpt.ATT.COM (bruce wong) (05/19/88)

In article <2552@ihwpt.ATT.COM> bwong@ihwpt.ATT.COM (bruce wong) writes:
>
>Do general purpose commercial multiprocessor systems *without* shared-memory
>exist ?

From one response I got to yesterday's posting I realize that I should
clarify my request.

By general purpose multiprocessor system I mean that the machine looks like
a uniprocessor machine to the user at the shell level and at the application
programming level.  The user is not concerned at all about processor allocation
and application partitioning.  This probably means that parallelism occurs at
the process level.

I read in EE Times that DEC has a version of their OS that makes their
multiprocessor shared-memory VAXen look like a uniprocessor machine.
Please tell me if this is incorrect.
NOTE: I'm interested in similar machines *without* shared-memory.

Please repy via EMAIL.  I will post a summary after sufficient verbiage has
been received.
-- 
	Bruce F. Wong	1A-111		312-416-5111
	ATT Bell Laboratories		ihnp4!ihwpt!bwong
	200 Park Plaza
	Naperville, Ill 60566-7050

rwa@auvax.UUCP (Ross Alexander) (05/20/88)

Bruce Wong @ somewhere.att asks about non-shared memory general purpose
multiprocessor timesharing-type machines (see subject line).  There
is such a beast - the AT&T 3B4000.  Runs Unix Sys V3.x, too; but
shared memory stuff is not supported between processes running on
disjoint processors.  So this machine's Unix is _not_ strictly SVID
compliant.  I wonder what Mr.  Gwynn @ smoke.brl has to say about
that ?  I personally was not teribly impressed.  As an aside, it
seems to me that the hardware would run a 4.2BSD kernal without any
rude violations of the BSD interprocess primitives ;-)

Ross Alexander, Athabasca University

res@ihlpe.ATT.COM (Rich Strebendt, AT&T-DSG @ Indian Hill West) (05/21/88)

In article <646@auvax.UUCP>, rwa@auvax.UUCP (Ross Alexander) writes:
> Bruce Wong @ somewhere.att asks about non-shared memory general purpose
> multiprocessor timesharing-type machines (see subject line).  There
> is such a beast - the AT&T 3B4000.  Runs Unix Sys V3.x, too;

The current release of the 3B4000 runs SVR3.1.1.

> but shared memory stuff is not supported between processes running on
> disjoint processors.  So this machine's Unix is _not_ strictly SVID
> compliant.

To pick a nit and correct a misimpression:  Shared memory is identified
in the SVID as a machine-dependent feature "and may not be present on
all systems."  So the 3B4000 does adhere to the letter of the SVID.
Shared memory, incidently, is available for processes on the SAME
processor, but is not available for processes running on different
processors.

				Rich Strebendt
				[iwsl6|ihlpe|ihaxa]!res
				[cuuxf|cuuxg]!iw1res!res