The collected works of bluecode - Page 4

That's called multiprogramming [1] [2] as far as I know.

[1] http://publib.boulder.ibm.com/infocenter/zos/basics/topic/com.ibm.zos.zconcepts/zconcepts_75.htm
[2] http://research.microsoft.com/en-us/um/people/gbell/computer_structures__readings_and_examples/00000294.htm

I don't consider Wikipedia "newer literature" and it is certainly far from authoritative. I do consider IBM authoritative since they were there with multitasking and multiprogramming and SMP much earlier even than UNIX and two decades before Sinclar QDOS (if we believe the dates on Wikipedia). Even so, the page you cited does use the word multiprogramming as I used it and doesn't explain the difference between that and "Preemptive multitasking/time-sharing" very well, nor could it, since preemptive multitasking and time sharing are not necessarily related. These words do all have clear, well-known definitions for the last 40 years or so. Revisionism doesn't help clarify anything! The people who invent stuff generally get to say what it's called. Not always, but more often than not.

No, but this does explain the confusion if you know the history on IBM, DEC, Bell Labs, and MIT.



This book is noted for being overly general. It's not a good reference. It's a very high level overview, very weak on actual details, and full of oversimplifications and overgeneralizations. It's not for people who actually go on to write operating systems or work on them.

Multitasking and time sharing are not one and the same thing at all. That's a broken analogy. It's like saying virtual storage and large address spaces are the same thing because most large address spaces are implemented through virtual storage.

Multitasking is a popular way timesharing systems are implemented, it's hardware and software. Timesharing is an application of technology to allow multiple users to share the same machine (hence the name timesharing). Nobody ever said that timesharing systems were designed to run one program, even with multiple tasks, contrary to what your quote seems to be suggesting by conflating the two terms. Timesharing systems let more than one person use the same box at the same time. That's all. Multitasking is the way timesharing is usually implemented, it is not timesharing itself. Multitasking is used for other things like making the best use of the processor or processors and getting more throughput, and to achieve a high level of concurrrency by scheduling the use of resources effectively. Multitasking has value independent of timesharing, timesharing is just one of the many possible benefits of multitasking. Timesharing is not multitasking. They're two totally separate things, although they are often related.



I don't have enough context. Are you saying the book defines multitasking as an extension of multiprogramming or timesharing as an extension of multiprogramming? Either way, it's the cart before the horse. Multitasking is one way multiprogramming and timesharing (again two different things) are implemented. Multiprogramming and timesharing can also be implemented through multiprocessing without multitasking. Conflating these things isn't correct or helpful in understanding anything. It's technically wrong, even if that's a popular or the most popular implementation. Reading the IBM doc helps since they invented and implemented most of this stuff originally and their hardware and software is still in use today, using the same techniques and principles as in the 1960s obviously with many enhancements etc. Like I said the guy who delivers something usually gets to call it whatever he wants. It's hard to argue on them.



That's also an oversimplification because one of the earliest, most pervasive and long-lived multitasking models is neither strictly preemptive nor cooperative but a hybrid. Doesn't the fact you're trying to bring proofs from wikipedia trouble you at all? Most of the people who actually wrote and work on this stuff don't hang out on wikipedia.



I'm sure it was in your operating systems class. But that doesn't really change anything. You have to actually know what you're talking about, you have to have been there, and written and used this stuff to know. That's how I know. Not from textbooks, not from people with an agenda, not from an MIT operating systems class, but by actually coding on those systems and seeing how they work, and reading the manuals written by the people who actually wrote the OS and designed and implemented all the technology. Not from some academic that never produced anything in his life except misinformation.



Renaming concepts is exactly what you're doing only you're trying to hang the responsibility on somebody else.

Thanks for your post. I'm sorry I got a little bent out of shape. Your good manners put an end to this hopefully and it now ends on a positive note because of that.



It's a good sign you weren't happy with the book. I have not seen any favorable reviews of it and when I skimmed it I found it very misleading. I do not know of a good general book, probably because to be general is to create exactly such a book that can't cover anything accurately enough or in sufficient detail. The other choices are really specific to a particular OS or family- for instance Bach or McKusick on UNIX, or Tannenbaum on Minix (but not on anything else!) etc. UNIX has portability as an overriding concern so most of the focus is on the software part of an OS. But other OS run on dedicated hardware designed for the OS (for example MVS and historically VMS etc.) and it is hard to find any information that addresses the specifics of those issues and without that you don't have both sides of the equation. Open source OS are much more approachable and lots of stuff has been written both good and bad. A lot of the proprietary stuff has virtually no 3rd party documentation or books on it so you only learn it from the manuals and (cough) reverse engineering (cough) and that was in a time when things were on a much simpler scale and they didn't hold things so close to the chest. Back then everything was in the manuals. Today things have become so complicated it's not possible for a person to even understand all of one compiler let alone a whole OS. And I'm not sure how useful it is to understand every operating system concept and implementation unless you're going to design a new OS. Most people (myself included) are happy just to find one OS they like working on and then drill down. The other stuff you just get in bits and pieces as you need it. A lot of people are learning OS concepts today by running vintage OS to see how things were done when a person could understand almost all of it.

I tend to focus on original sources and I view with suspicion anything from academia unless the guy has had some success at actually delivering something. Stroustup is a rare example. Wirth did some important work but in the end nothing he did seems to have ever been implemented well, despite the good concepts behind it. People picked up where he left off, fixed the shortcomings, and produced something usable. He himself never did AFAIK. You never go wrong by finding out the history behind something and understanding the way it was first designed and implemented. That's the best basis for building on stuff because of the "those who don't know history are condemned to repeat it" thing. I'm not talking about stuff that came out and died a week later or fringe concepts but stuff from the early days that passed the test of time and proved it was a good design and has turned out to be extensible for decades. That's what I love about what I work on. Everything from the old days still runs unchanged but today's version is more capable and smoother than ever before. OTOH I see a lot of thrashing and bad implementations today of stuff that was already done correctly and elegantly many years ago and it's frustrating to have to keep banging your head against it and that is mostly what bothered me about this discussion. Even though UNIX and Intel are the overwhelming popularity contest winners today they are not the best of breed and weren't the first in almost anything and really didn't blaze any technical trails. They did a lot to bring computing to the masses and get lots of people coding which is certainly important. But they're far from all there is. Let's give credit where credit is due. And you have to keep your eyes open for that.

So now I am confused although when I first read your response I thought I got it. So what's supposed to run on Altix, only Linux? I mean did I understand you to say a HP/UX, Tru64 (before it got discontinued) and OpenVMS will all run on HP Integrity but only Linux runs on Altix??? My brain hurts

That's hard to figure, isn't it? You would think all the cameras and music devices would use ext2 since it was open, but they used FAT!
I want a camera with ext3 so I can say I have a camera that uses a journaling filesystem
Those fscking cameras!

Thanks. That's sounds like a colossal waste of time and money for whoever dreamed that one up. Is there any way they could make Itanic even less useful than it apparently already is? The mind boggles.

Your English is great, better than I could speak your language I'm sure! Yeah a pitcher of beer always seems to smooth things out. If that doesn't work there's always the waitresses who bring it



Yes, I wish I had certain pieces of vintage (and current!) hardware but if you don't live in America a lot of that is real hard to come by. Emulators have done such an amazing job of letting people try stuff they never had a chance to work on, but there's nothing like real hardware.

I see a lot of guys giving away equipment and of course nobody lives within 10,000 miles of me usually. People shouldn't think their generosity isn't appreciated or that people don't want this stuff. It's probably just that people who live in America where all kinds of stuff is cheap already have most of what they want and those of us who don't can't afford the shipping.

Major Bummer, reporting for duty, Sir!

That's just nasty, hamei. I won't be able to sleep for a week now!

Aooooooooooooooo! Werewolves in London! Aooooooooooo!

I understand that. This was in response to your answer to my question "Will OpenVMS run on these" and you said no. So Altix is a dedicated oddball Linux platform? And that's it? That's what I meant about "making Itanic even less useful than it apparently already is." Altix for some reason(?) can't run the main (only?) OS actually ported to Itanium as a dedicated home platform. That's called making Itanic even less useful than it apparently already is. It's not like they had 100 possible OS choices and they could afford to preclude 50 of them from running on them. They can't support the main Itanium OS... why not?

What OS did I want? Anything but Linux. The last thing the world or any individual needs is another discontinued expensive proprietary oddball Linux platform. It's a colossal waste of time and money for no benefit over platforms that are already available and already run Linux better. Intel knows this, they're already out of the Itanium compiler business. Everybody's who has any sense is bailing. What's the point of this?

I'm all for new platforms, look at my icon! But this feels like people can't admit defeat and are putting out bizarre stuff for nothing but masochistic reasons.



I don't know the history but i ASSumed OpenVMS was one of the first if not the first OS to be ported to Itanium. If Altix can't run IRIX and it can't run OpenVMS and all it can run is Linux then it seems like a colossal waste of time and effort for anybody to make it and Itanium is dead for all intents and purposes anyway. Is there no shortage of cheaper/faster platforms including Intel x64? I don't see the point of this. At all. Whoever did this should be taken out and shot and then picked up and shot again. Twice.

It is very nice that FreeBSD might support it. Any additional OS choices are good. But that is after the fact. I still don't understand why anybody would spec out and build an Itanium box that could only run Linux (as far as they knew). Oh I'm sure you can get all the apps you need from itanicpackages.net and all but as soon as you get off Intel Linux is already not very friendly. This just doesn't make any sense. If it would have run OpenVMS then at the time it would have made sense. But now?

Can I think of realistic candidates? No, that's the whole point. Nobody can. Now that OpenVMS is going away and Intel (the guys who make the hardware) have stopped compiler development for the platform it's dead. There's no point in prolonging the agony. Why oh why do we have to see this?

Ok, thanks for the explanation. I figured I was missing some important facts. Sorry about any unintended thread-derailment.

Hi I have no idea about anything SGI or IRIX but this looks wrong. One I think you're supposed to use something like



while you have



The message you get suggests it's looking on your local system for /nekoware.dustytech.net and that would explain it.

On the remote chance this might help...because I am almost always wrong about anything UNIX-related but since nobody answered yet I tried anyway. What bravery!

Glad you got it working. Another satisfied forum customer

smj, good eyeball on my post. Actually I left out the extra colon just from habit. I use rsync a lot. What was critical was the placement of the slash character. It has to come after the colon(s). In his example he had it before and I think that led to the shell expanding it to a local path that didn't exist. That was the error message. Nothing to do with the extra ":" afaik.

The format for scp and rsync is something like



or



I never used the :: but it does mean something according to the rsync man page.

Bluecode, Batting 1/10,000 on UNIX issues and emboldened greatly by an elusive and unexpected tiny measure of success, however ephemeral or insignificant it may well have been.

Interesting you say that. IBM did some studies decades ago and they found producitivity was directly correlated with response time of the machine. I wish I had the results in front of me. I can't find the article and everything is now behind a paywall. But one thing stood out: if it takes more than a second for the system to respond to you it destroys your thought process and productivity goes down the drain. This was 20 or more years ago. I am sure now when people are used to subsecond response times everything is recontoured around expectations. For development, editing etc. response time surely matters if you care about getting anything done. It is very frustrating to switch applications on a normal desktop and wait to be swapped/paged in again or have your mouse freeze when you have a process reading from disk. Try doing a long find and then getting anything else done at the same time on a normal desktop. Not happening.

Those are really nice little machines. Lotta fun!

I think their results show it goes further than just slowing down. It actually kills productivity because people can't work at their own rate. If it only made things slower that would be one thing. But it seems much worse, and that's my experience also- that if your editor or debugger or other tools get in the way they change from tools to another part of the problem. What the study showed was that bad response time disrupts the creative process in destructive ways. As usual, the answer will be to throw more hardware at the problem. But try as they might, that just does not seem to do the trick.

Really? When did this happen? I could use a boatload of 146G 10 or 15K for my Sun boxes.

That's a good price. I haven't seen anything less than 75 bucks for the 146G plus another 20 dollars shipping each and most seem to be over a 100 dollars each. Last time I checked the prices on the 300G were nearly 200 dollars a piece. Where are you guys finding this stuff? ebay or somewhere else?

Wow that's a great deal. Do the FC drives work in place of Ultra320? I have no idea what the difference is and I don't have a storage array.

I never thought about it because I don't have much equipment but I read a post on here that I can't find now that said something about not letting hardware sit powered off for too long. What do you guys think, how often should servers and PCs and similar devices be allowed to sit without being powered on and used for awhile?

Today I had a bad experience with a PC that had been shut off but left plugged in since the end of May. I turned it on and nothing happened. I had problems with this mobo before and whenever the battery dies it fails to post. But this time it didn't even come on. I tried switching it off at the PSU in the back and tried starting it again and there was a very loud crack like somebody lit a firecracker. And it stank. Amazingly it started and ran fine. After a while I turned it off and turned off the power to it and when I am less aggravated I'll open it up and look for a blown capacitor. This made me wonder about the servers I have sitting around that I can't use as much as I would like because of noise/heat/UPS/electric bill issues. How often should they be operated to keep them in good condition?

Thanks.

Ok thank you.

Thanks guys. Last time I did search on my part numbers because I realized I don't know enough to tell whether anything else will work and everything I found was $$$$$$. When I have more cash I'll look into this again.

Thanks guys. Vishnu I realize stuff has a theoretical service life but there does seem to be something to the idea that equipment left running doesn't fail very often for some reason.
Yeah the mobo battery dies fast on this mobo if I pull out the plug and when it does the mobo doesn't post. Real fine piece of work.

Hamei, if you didn't turn this thread into a corporate rant I would have had to PM you to see if you're ok Dude! Faxxing you a virtual six-pack. Drink to me, drink to my health, ...!

I have not found any cheap ECC PC2100 RAM in 2G sticks with 2.0 latency. Like somebody else said the 2.5 seem a lot more common. But they are also not cheap. Where are you guys finding all this hardware bounty?

eBay stuff comes and goes but have not found this ram cheaper than $15 a gig and that was for cl2.5. That works out to 240 bucks for 16G of used RAM in who knows what kind of condition. What's a good price on this stuff?

Somewhere there is a list of what RAM speeds and latencies are supported by what OpenBoot version. The SunFire servers came with PC2100 but the later OBP allowed you to go higher.

As somebody who doesn't use Lisp or know much about it I still see the value in it. The syntax is very straightforward. People know how to implement it and get good performance out of it since it's been around a long time. Other functional languages are too ugly and wierd and have problems with performance and garbage collection for edge-cases. Maybe in the future that will improve. Lisp is something old school that's proved itself. I tend to like old stuff.

I realize you can use 2.5 latency but it's slower than the spec'd ram. These boxes are fast for what they are but there's no reason to handicap them if you can still find CL2.0 sticks. Ok, 2G for 8 EUR is a good reason

I remember a major state university (est. 50,000 students and 10,000 staff) ran their total computing program with about 12M of RAM spread across two mainframes. This supported the school itself, large comp sci and EE departments (along with other science departments but I didn't know people in those programs) and ran ALL the reporting for a local bank network at night. They didn't need two mainframes for this but at the time they used to crash a lot and they were sponsored to the university (free) so why not. So yeah. It shows you can get an unbelievable amount of work done if you start off with good hardware and software.

If spying on innocent people didn't require so much storage and processing we'd probably all be working on 30MHz workstations with 16M of RAM and liking it. Instead we find 3x2 GHz CPUs and 2G of RAM is an absolute minimum for a functional desktop even under Linux.

works for me! Besides, I like Chinese people.

What are the choices? I don't even know what "workstation" means. If a workstation is an application-delivery platform then maybe it doesn't need an OS. Given the OS choices I'm aware of, not needing an OS might actually be A Good Thing.



Is Linux even an OS? Or is it the OEM equivalent of what we were talking about earlier where 3 companies in the world actually make anything and everybody else just rebrands...