[dba-VB] Parallelism

Hi Jim --

Yes, "fork", but before that was IBM360, which has had special hardware and
operation system software to handle Input/Output channels, multiplexing
console input etc. - and when that special hardware has been working for
input/output CPU was idle, and could have been used by other application
processes - AFAIKR even PL/1 has had some function calls to start and handle
long running "independent" threads within a running process/task, but
starting an independent task that wasn't possible on application programs
level (?) for IBM360 MFT and MVT OSes, and in mid-1970-ies, the next IBM OS,
MVS, has got multi-processor systems support they say: well that all was
very expensive that times of course and not broadly available as nowadays
multi-core mass market computer systems but all nowadays Parallelism and
Multi-Threading concepts were mainly developed during that "ancient" times:
and then came MS and has been keeping us in "preemptive multitasking"
"straitjacket" for almost 20 years - was that good, bad, necessary and
inevitable MS-driven "moderation and control" for technology mass market to
mature?...

Thank you.

-- Shamil

-----Original Message-----
From: dba-vb-bounces at databaseadvisors.com
[mailto:dba-vb-bounces at databaseadvisors.com] On Behalf Of Jim Lawrence
Sent: Sunday, May 23, 2010 2:04 AM
To: 'Discussion concerning Visual Basic and related programming issues.'
Subject: Re: [dba-VB] Parallelism

Hi Shamil:

Since the first Unix system added the command 'Fork' there has been parallel
processing... (http://en.wikipedia.org/wiki/Fork_(operating_system) Yes, it
could have very well been the 60's 

Jim



-----Original Message-----
From: dba-vb-bounces at databaseadvisors.com
[mailto:dba-vb-bounces at databaseadvisors.com] On Behalf Of Shamil
Salakhetdinov
Sent: Saturday, May 22, 2010 12:44 PM
To: 'Discussion concerning Visual Basic and related programming issues.'
Subject: Re: [dba-VB] Parallelism

Hi Jim --

Thank you for your remark.

Yes, I suppose I do realize the difference between multi-threading and
Parallelism. And I suppose I do use both here in my everyday development:

- Parallelism can be implemented by using multi-threading (long running
threads usually performing conceptually different tasks) but it can be also
implemented by running independent processes...

- Multi-threading is usually treated as multiple short-living
threads/-sub-processes running within one process, and often performing
conceptually the same tasks, at least most of the threads of a
multi-threaded application...

Both Parallelism and Multi-threading can be implemented on one CPU provided
independent processes or threads have some waiting/idle time - waiting for
some external events to happen/tasks to be processed - that concept exists
since IBM 360 MFT OS times (early 60-ies?)...

Both Parallelism and Multi-Threading are getting mainstream nowadays when
one process, which can't be "paralleled" on one CPU system because it has no
"external events" to wait, can now be split into several
sub-processes/threads to be scheduled to run on several CPUs/cores available
within one computer - that's new for mass market PCs, but this concept of
Parallelism/multi-threading is rather old coming from supercomputers - CRAY
and CDC there, and Elbrus here (also 60ies AFAIKR)...

Please correct me if I'm wrong.

What's so new with "the new Parallelism" you mentioned?
What am I missing? - Let's define this discussion thread context: I do not
mention "neural networks" and "clouds" here - we are talking within context
of one physical unit having several CPUs/cores and controlled by one
operation system instance, correct?...

Thank you.

-- Shamil 

-----Original Message-----
From: dba-vb-bounces at databaseadvisors.com
[mailto:dba-vb-bounces at databaseadvisors.com] On Behalf Of Jim Lawrence
Sent: Thursday, May 20, 2010 1:50 AM
To: 'Discussion concerning Visual Basic and related programming issues.'
Subject: Re: [dba-VB] Parallelism

Hi Shamil:

Please note that the lecturer gave a very strict line of difference between
multi-threaded applications and the new Parallelism... they are very
different in coding, deployment and performance.

It now appears that the preparation of coding will now take twice as long
but it appears to be the only way to be able to get full performance from
our new multi-cored computers.

I understand that some Linux systems manage the Parallelism within their
kernels so a new application may not see as great as performance advantage
as on a Windows OS... but some List members may have far greater insight, on
this subject, than I do.

I had previously sent an email to Tiberiu Covaci asking for some
clarification on the points and differences and as soon as I hear a reply, I
will share that information.

Jim

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