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Comparing Linux To System VR4

timothy posted more than 9 years ago | from the pick-your-perspective dept.

Operating Systems 208

robyannetta writes "Paul Murphy from LinuxInsider.com asks the question What's the difference between Linux and System VR4? From the article: 'If there's a real bottom line here, the one thing I'm clear on is that I haven't found it yet, but the questions raised have been more interesting that the answers -- so more help would be welcomed.'"

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Various differences (3, Informative)

Lindsay Lohan (847467) | more than 9 years ago | (#11390490)

So what's the difference between SVR4 and Linux? At a glance they may look the same because they're both in the Unix family, but they're actually quite different.

GNU/Linux has a wider variety of software natively written for it

the Linux kernel includes support for more hardware than SVR4

Linux is more popular as a desktop operating system than SVR4.

Another important factor to consider for many users is price, although there are inexpensive and free versions of UNIX.

Linux issues and bugs generally are often fixed extremely fast.

For a more in-depth technical reference, see this good article [over-yonder.net] on the fundamental difference between BSD and UNIX (although BSD is not technically SVR4 it's still a good read).

Re:Various differences (3, Insightful)

Lawrence_Bird (67278) | more than 9 years ago | (#11390620)

mmm.. when people ask a question like that I tend to think
more of the technical aspects, ie like threads and smp and
stuff like that and how its implemented differently. Not
that the qualitative differences aren't of some import too
but I just see that more as the color of the cars vs the
types of engines/trannies.

nice link on bsd philosophy.

Re:Various differences (0)

Anonymous Coward | more than 9 years ago | (#11390740)

mmm.. when people ask a question like that I tend to think more of the technical aspects

Well you might think like that but I appreciated the general comparisons. Everything isn't about bitfiddling and pthread variants, sometimes the basics help to clarify for the beginner.

RTFA (0)

QuantumG (50515) | more than 9 years ago | (#11390632)

It's a technical comparison between the Solaris and Linux kernels. He's not interested in your opinions of which makes a better embedded operating system for a toaster oven.

Re:RTFA (0)

Anonymous Coward | more than 9 years ago | (#11390859)

Well put.

Re:RTFA (0)

Anonymous Coward | more than 9 years ago | (#11390892)

I've never seen a desktop in a toaster oven, but maybe they have one somewhere in Japan I guess. Mod GP up :)

Re:RTFA (5, Interesting)

Bruce Perens (3872) | more than 9 years ago | (#11390955)

He's not interested in data either. The article's a troll, with almost zero real technical content.

Bruce

Re:RTFA (1)

QuantumG (50515) | more than 9 years ago | (#11391035)

It's a follow on from another article. If you havn't read the other article then it makes no sense to read this article. The only reason why the brain dead Slashdot editors posted it is because the brain dead OSNews.com had it. I'm sure neither Eugenia over at OSNews, nor timothy here on Slashdot read anything more than the title of the article. Not even knowing what VR4 was refering to they posted it.

Re:RTFA (0, Flamebait)

SpaceLifeForm (228190) | more than 9 years ago | (#11391095)

I have to agree. I thinking that SCO/MS is behind this.

Who cares about SVR4 these days anyway?

Re:RTFA (1)

QuantumG (50515) | more than 9 years ago | (#11391131)

Wow, what a brilliant part of the Microsoft plan! How could we possibly not have recognised this as part of their ploy!

Maybe, just maybe this isn't part of the great SCO/MS conspiracy and you're just confused cause you don't have half the article cause you don't read the news site it is posted on and you don't follow this author's work?

Re:RTFA (2, Informative)

lakeland (218447) | more than 9 years ago | (#11391233)

Is it a troll? I found it too confusing to say. The article is looking for technical differences between linux and SVR4. Consider this quote: "Specifically, what's needed here is the low level programmer view, not of what's out there by way of applications..."

The impression I got was the author was way over his depth writing it, and was largely aware of this. Consider the final conclusion "If there's a real bottom line here, the one thing I'm clear on is that I haven't found it yet". Now, that's either a very good troll or a genuine article.

As for answering the article. Well, the painfully obvious difference is in hardware support. SVR4 is a joke in terms of hardware support compared to linux.

In terms of 'features' like kgdb, ptrace, LVM, NUMA, SMP, well I don't think I even know enough to make an informed comment. I will note that the author's attempts to draw comparisons appear extremely weak to me (particularly WRT threading).

Also, the author also seemed to confuse a number of architectural weaknesses with kernel weaknesses. Run linux on a toy mainframe and it won't have mainframe hardware features. Well, Doh. Run Solaris on personal computer hardware and it won't either. Run linux on mainframe hardware and it will.

So, I consider the article very weak, and not worth the electrons it was distributed on. However, it is a fair enough question to ask. It is just a pity to ask it so badly and then slip in bits like the SCO lawsuit for extra hits.

Re:RTFA (2, Insightful)

j_w_d (114171) | more than 9 years ago | (#11391093)

It's a technical comparison between the Solaris and Linux kernels.

irony-on And the unsubtle implications concerning the changes in 2.6 respecting the SCO-IBM fracas are legitimate technical observations. irony-off

The article read like troll-bait to me. A serious journalist could have simply asked developers what the technical differences are and how they are affected by the intended platforms. A serious programmer could have answered his own questions. What class does that leave article's author in - bridge dweller?

Re:Various differences (1)

Steve Embalmer (783552) | more than 9 years ago | (#11390661)

Thanks, that link was interesting and you made alot of good points, except the one about Linux and desktop OSs... Solaris has a rocking good desktop manager.

Re:Various differences (2, Insightful)

Anonymous Coward | more than 9 years ago | (#11390813)

Okay, I call B.S.

> # GNU/Linux has a wider variety of software
> natively written for it

There is a huge base of professionally written
and supported apps for SVR4/Solaris/UnixWare/...
The GNU compiler and toolchain, while useable,
perhaps even good, is inferior to the offerings
from Sun, IBM, HP, and the commercial vendors.
The same can be said for nearly, if not every,
category of GNU/Linux/Open-Source software.
Linux may in fact have more "stuff" available
for it but when you weed out the crap, it isn't
that impressive.

> # the Linux kernel includes support for more
> hardware than SVR4
>

No it doesn't. Their is little if no support
in Linux for Sun, HP, DEC, Compaq, IBM hardware.
And with few exceptions, what support is in place
is pretty poor. Likewise, when you look at the
offerings from Sun, SCO, and others, the amount
of support on the PC is just about as good.

> # Linux is more popular as a desktop operating
> system than SVR4.
>

Maybe, but maybe not. People at home and dorm
geeks dork'ing around don't count. I'll guarantee
you their are more scientific and engineering
shops that are using SVR4 based desktops than
Linux.

> # Another important factor to consider for many > users is price, although there are inexpensive > and free versions of UNIX.

Define "price". Having to wait around for days
on end while somebody on the mailing list or web
forum decides to answer your question (or some-
times not at all)is unacceptable. Sun, HP, and
IBM, provide guaranteed response times and they
do it well. When your systems are down and
costing you $5000 an hour open-source "support"
don't cut and ends up costing you a lot more.

> # Linux issues and bugs generally are often fixed extremely fast.

Sometimes yes, sometimes no.

Re:Various differences (0)

Anonymous Coward | more than 9 years ago | (#11390873)

Their is little if no support in Linux for Sun, HP, DEC, Compaq, IBM hardware.

What planet are you living on...?

Oh, that was a troll... sorry.

Re:Various differences (0)

Anonymous Coward | more than 9 years ago | (#11391033)

Actually, Linux support for midrange hardware is pretty crappy. SGI makes a box, but that's about it. IBM doesn't.

Re:Various differences (2, Informative)

Anonymous Coward | more than 9 years ago | (#11391433)

Read this [ibm.com]

You are such a fucking loser your monger.

I'll give you a rundown of the categories on that page, in case you are too lazy to read it.

Linux on POWER
Linux on Intel processor-based servers
Linux on AMD processor-based servers
Linux on Mainframe

The Linux s390 and PPC and PPC64 (and even m68k) architecture maintainers all work for IBM. The POWER5 processor had features designed with Linux in mind to better suit its low level memory management system. The IBM Linux guys go do Linux bringup and verification on sample silicon.

Oh also, the Linux IA64 maintainers work for Intel and HP, both companies have quite a few staff doing Linux (especially ia64) work. SGI has a lot of staff working on the kernel alone.

Sun these days is probably not supported as well, but why would you buy a sparc server running Linux when you could buy an Altix, or a POWER5 (or zSeries if you want a real mainframe)? You would have to be insane. The only reason sparcs are still being sold is the solaris on sparc legacy.

Re:Various differences (1)

defile (1059) | more than 9 years ago | (#11391032)

Define "price". Having to wait around for days on end while somebody on the mailing list or web forum decides to answer your question (or some- times not at all)is unacceptable. Sun, HP, and IBM, provide guaranteed response times and they do it well. When your systems are down and costing you $5000 an hour open-source "support" don't cut and ends up costing you a lot more.

What the hell? You don't get enterprise support for free as a result of popping in a Solaris installation disc. Why would you expect one if it's Linux disc?

Re:Various differences (2, Insightful)

Pseudonym (62607) | more than 9 years ago | (#11391091)

Here, have a few goats...

There is a huge base of professionally written and supported apps for SVR4/Solaris/UnixWare/...

Correct, kind of. There are arguably more commercially supported apps for Unix or Solaris than for Linux, and generally speaking, more money is involved. (That is, the apps in question are serious ones that companies rely on; if the software fails, the company goes south.)

Having said that, there are probably more "professionally written" apps for Linux, it's just that most of them aren't as commercial or mission-critical.

The GNU compiler and toolchain, while useable, perhaps even good, is inferior to the offerings from Sun, IBM, HP, and the commercial vendors.

That depends what metric you use. If the only measure that you use is the performance of generated code, then I will concede that you're probably right. On the other hand, the GNU compiler tends to be much more standards-compliant than its commercial competitors. The GNU toolchain is ported to more architectures and platforms than any other. Moreover, the open source suite has more "off the shelf" than any other (e.g. valgrind, though it's not ported to anything other than IA32), where on the Sun or IBM systems you'd need to buy something extra (e.g. Purify). One notable exception is the Sun ONE Studio performance collector/analyzer; I haven't seen anything like it for Linux.

The same can be said for nearly, if not every, category of GNU/Linux/Open-Source software.

Strongly disagree. In the desktop arena, open source is way ahead of commercial Unix.

Commercial Unix definitely has the upper hand here because they can use the best of open source as well as the best of proprietary. So, for example, you can run Apache on your Solaris machine and get the best of both worlds, so to speak.

Linux may in fact have more "stuff" available for it but when you weed out the crap, it isn't that impressive.

That's a false dichotomy, and Sturgeon's Law applies here. There's a lot of crap in Linux, but that's because there's a lot of stuff, and 90% of everything is crap. The 10% left over is equally impressive, but it tends to do different things than the 10% of commercial offerings which aren't crap.

Open source doesn't have a "Verilog-killer", but commercial Unix doesn't have an "Apache-killer".

Re:Various differences (1)

terrox (555131) | more than 9 years ago | (#11391176)

.... Linux is something "most computer users" have heard of whereas SVR4 is not. This is just something to get noticed.

Distribtuion method (5, Funny)

niteice (793961) | more than 9 years ago | (#11390507)

Well, Linux can be downloaded in a friendly ISO format, but my SVR4 2.1 disks are in some wierd-ass format I can't use with anything except this one german program.

Different (-1, Redundant)

Anonymous Coward | more than 9 years ago | (#11390512)

They are wriiten differently and spelled differently. No characters in common.

God..I love tacos (-1, Troll)

Anonymous Coward | more than 9 years ago | (#11390520)

MMMMMMMMM Mmmm mmmmmmmmm MMMMmmmmm mmmmmm

just buy a mac (-1, Troll)

Neuropol (665537) | more than 9 years ago | (#11390531)

and get it over with.

The difference is... (2, Funny)

FiReaNGeL (312636) | more than 9 years ago | (#11390535)

That everyone says "What you said?" when they're asked about VR4.

Lets compare apples to apples, would'ya?

Re:The difference is... (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#11390678)

SVR4 sounds like a virus and Linux is the cure.

Re:The difference is... (-1, Offtopic)

Anonymous Coward | more than 9 years ago | (#11390710)

"What you said?"


you have no chance to survive, make your time! HA HA HA...

Re:The difference is... (4, Funny)

0racle (667029) | more than 9 years ago | (#11391186)

Apples are BSD based not SysV.

Re:The difference is... (1)

idiotnot (302133) | more than 9 years ago | (#11391341)

Haven't always been [wikipedia.org] .

And, on a kernel level, OSX isn't BSD, either. It's mach, which has things like native threading, and its own message-passing facility...separate from what you'd find in a traditional unix kernel. (NetBSD supports Mach IPC now, too, to support Darwin binary emulation)

Re:The difference is... (1)

0racle (667029) | more than 9 years ago | (#11391509)

It was a joke.

Re:The difference is... (-1, Flamebait)

Anonymous Coward | more than 9 years ago | (#11391578)

No it wasn't you fucker. You're just plain wrong; *you* are the joke.

The difference is obvious (0, Troll)

kevingc (824034) | more than 9 years ago | (#11390541)

We've heard of one and not the other.

Re:The difference is obvious (0)

Anonymous Coward | more than 9 years ago | (#11390616)

Never heard of SysV? I seriously hope you're joking...

(I can understand never having used it. But never heard of it? Sheesh.)

Re:The difference is obvious (0)

Anonymous Coward | more than 9 years ago | (#11390717)

Don't laugh. Half of the people here have never heard of GNU/Linux either.

They use Gentoo, d00d, and it R0X0|2Z!!!!!!111!

Re:The difference is obvious (0, Flamebait)

sp0rk173 (609022) | more than 9 years ago | (#11390981)

Please remove your slashdot accound. Your assumed clever comment has shown you to be, as esr would say, a "luser." But, then again, esr is a loser. So, go figure!

Meh (-1, Troll)

Anonymous Coward | more than 9 years ago | (#11390542)

Unless it runs on MacOS or will be available in a smaller form factor of varying stylish colors, I fail to see how this is postworthy on Slashdot.

Linux is much more revolutionary (0, Troll)

Amsterdam Vallon (639622) | more than 9 years ago | (#11390554)

I've worked on dozens... dozens of Linux applications, including ones running at very low system levels.

No other OS is more evolutionary than Linux.

Not BSD. Not Windows. Shit, not even OS X.

Look at how far Linux has come in a little over a decade. It's amazing and awe-inspiring.

Sometimes I sit at home and stare up at the posted of Linus that I have on the wall and just think, man, that guy started something huge and important, how incredible it all is. Then I touch myself (-;

Re:Linux is much more revolutionary (0)

Anonymous Coward | more than 9 years ago | (#11390578)

You dissed osx, be prepared for a troll mod.

The Facts (-1, Troll)

Anonymous Coward | more than 9 years ago | (#11390777)

Like 99% of Free Software, Linux is a clone of proprietary technology. Nothing in Linux is original.

Copying is easy. Linus is not special Thousands of people have written shitty UNIX clones. Linux has gone nowhere in a decade. Linus is a lazy WASP.

Re:The Facts (0)

Anonymous Coward | more than 9 years ago | (#11390811)

WASP

Actually, he's a WSA - a white, Scandinavian agnostic.

Not his first great article (-1, Troll)

Anonymous Coward | more than 9 years ago | (#11390560)

Paul Murphy has written some great and insightful articles about comparisons between these two systems. Although the previous one that I read might not be as informative, it definitely is worth looking at [google.com] . In that article, he doesn't look for much (if any) input from outside readers. I also noticed that he leans somewhat towards the Linux side of things.

yeah but I love his lyrics man (-1, Troll)

Anonymous Coward | more than 9 years ago | (#11390669)

White on white translucent black capes
Back on the rack
Bela Lugosi's dead
The bats have left the bell tower
The victims have been bled
Red velvet lines the black box
Bela Lugosi's dead
Undead undead undead
The virginal brides file past his tomb
Strewn with time's dead flowers
Bereft in deathly bloom
Alone in a darkened room
The count
Bela Logosi's dead
Undead undead undead

Sigh (4, Informative)

devphil (51341) | more than 9 years ago | (#11390569)


It took me three paragraphs before I figured out that the author of the article wasn't talking about an operating system called "VR4".

Whitespace matters, people. "SystemV R4" or "SVR4" or "SysVR4" woulda done just fine...

Re:Sigh (1)

kbahey (102895) | more than 9 years ago | (#11390958)

Exactly what I thought. I have been using System V since R2, and SVR4 since it first came out (before Solaris came out even).

I have seen it as : SVR4, System V Release 4, or SysVr4 even ...

But System VR4 ? Never saw it spelled this way, and indicates little familiarity with the subject matter.

The difference is... (5, Funny)

mrogers (85392) | more than 9 years ago | (#11390597)

You can't buy SVR4 bumper stickers.

Looks like a troll to me... (3, Interesting)

jpetts (208163) | more than 9 years ago | (#11390609)

LinuxInsider has on several occasions in the past been a troll site for the SCO/IBM Linux dispute, coming down firmly on the FUD-mongers' side. They are a platform for people like Enderle, DiDio. Ignore, is my advice...

Re:Looks like a troll to me... (0)

Anonymous Coward | more than 9 years ago | (#11390836)

LinuxInsider has on several occasions in the past been a troll site for the SCO/IBM Linux dispute
Publishing both sides of the debate does not make LinuxInsider a "troll site."
They are a platform for people like Enderle, DiDio
...and anybody else with something interesting to say re: Linux.
Ignore, is my advice...
Slashdot Reality Distortion Field: Activate

"FUDFUDFUDFUD I CANT HEAR YOU"

Re:Looks like a troll to me... (1)

PenGun (794213) | more than 9 years ago | (#11391252)

ASsTROllTURF, I'd guess.

PenGun
Do What Now ??? ... Standards and Practices !

Re:Looks like a troll to me... (1)

worldcitizen (130185) | more than 9 years ago | (#11391036)

Hehe, at some point I thought that the name linuxinsider came from trying to do an "inside job" (although, they didn't really seem to be inside anywhere :P)

My Thoughts Exactly (1)

oli_freyr (105995) | more than 9 years ago | (#11391135)

Just a "me too", nothing to see here... ;)

Almost all articles on LinuxInsider seem to have one thing in common: look legit to the PHB's out there, but contain a grain of FUD, that when joined could fill a FUD-shaker...

Being that this is /. (5, Insightful)

Anonymous Coward | more than 9 years ago | (#11390633)

I'm sure nobody bothered to actually RTFA.

The article is basically worthless. It's like walking through a classroom about 20 minutes into the lecture, and walking out 15 minutes later.

It starts in the middle, and leads nowhere. Just a bleem of time that, for whatever reason, is, unfortunatley, recorded here for posteriry.

In Korea,.... (-1)

Anonymous Coward | more than 9 years ago | (#11390653)

Only old people use SVR4.

SVR4 utilities (0)

Anonymous Coward | more than 9 years ago | (#11390665)

Gunnar Ritter maintains a huge set of SVR4 utilities: The Heirloom Toolchest [sf.net]

L-A-M-E (5, Insightful)

johnthorensen (539527) | more than 9 years ago | (#11390666)

Could this guy TRY to be more disparaging in his tone? Sure, he tries to give a little back with a comment regarding the quality of Linux code, but for those that haven't RTFA, here's the gist:

1) Linux runs on a 'toy' platform (x86), and why the hell would a programmer want threads when there's not TRUE concurrency?

2) Linux does nothing significant that AT&T wasn't doing 10 years ago.

3) Generally speaking, Linux sucks.

IMHO I expect to see this sort of thing about half-way down in a thread of /. comments, not on an actual computing news site.

-JT

Re:L-A-M-E (1)

McAddress (673660) | more than 9 years ago | (#11390798)

1) Linux runs on a 'toy' platform (x86), and why the hell would a programmer want threads when there's not TRUE concurrency?

It's not that a programmer would not want threads. However, if you want threads to handle truly concurrent events, as opposed to just multiple strongly related processes, the design of the threads will be entirely different. His point was that on an x86 any attempt to design truly concurrent threads is a waste of time b/c of the underlying architecture. Of course Linux runs on more than just x86 hardware, so the point moot.

Re:L-A-M-E (0)

Anonymous Coward | more than 9 years ago | (#11390901)

Which is really stupid: when you need to wait on I/O it's a really good idea to have some real form of threading and concurrency, when you have a kernel with some form of preemption you cannot go without a system designed for concurrency.

On a side note the main underlying architecture for Linux will probably be in the comming years SMP x86-64 ... which means _real_ concurrency ...

Re:L-A-M-E (3, Interesting)

FyRE666 (263011) | more than 9 years ago | (#11390848)

As another comment above noted, "LinuxInsider" is not a computing news site in any real sense of the term. It is in fact little more than a FUD factory. The list of contributors reads like the who's who of Microsoft/SCO paid schills...

I'm surprised that Slashdot gave this latest garbage a front page headline. Hopefully if enough people ignore LinuxInsider it'll go away...

SVR4 (1, Funny)

tuxter (809927) | more than 9 years ago | (#11390667)

Sounds like a new performance vehicle.

What does this say? (5, Interesting)

aluser (771756) | more than 9 years ago | (#11390677)

There are several paragraphs in the article which, I think, don't actually say anything. Example:
Imagine, for example, trying to build a compiler able to produce an efficient executable in exactly one pass. Nobody does this now, for obvious design reasons consequent to an underlying sequential processing assumption, but it shouldn't be impossible. "All" it would take is a complete re-appraisal of everything we know about optimization and related issues in a truly concurrent, shared-everything, multi-threading environment with enough threads.
Am I completely out of my depth? What does threading have to do with efficient one-pass optimizing compilers? What's his issue with concurrency under linux anyway?
Or this:
On the other hand, this variation on the main question also raises new issues because many of the changes made to process and memory management between the 2.4 and 2.6 Linux kernels look a bit artificial -- meaning that they don't seem to be direct continuations of code evolution up to 2.4 and thus raise the suspicion that the SCO/IBM lawsuit might be having some unexpected design consequences.
What makes a patch "artificial" ? Whatever that means, how does it imply anything about the sco/ibm lawsuit? Weren't the 2.5 development line split and the major scheduler changes introduced before the lawsuit? Even if not, what would he consider a continuation of the development up to 2.4? In short, can somebody explain to me what this guy is saying?

Re:What does this say? (4, Funny)

ScrewMaster (602015) | more than 9 years ago | (#11390755)

Well, doing a little reading between the lines, as it were, I think what he's really saying is "I want to pay off my mortgage early and this is the best way I've found to do it."

bahaha (1)

sp0rk173 (609022) | more than 9 years ago | (#11391057)

NICE.

Re:What does this say? (2, Insightful)

Pseudonym (62607) | more than 9 years ago | (#11390877)

What's his issue with concurrency under linux anyway?

I didn't get that either. I had some (very serious) issues with concurrency in Linux, but they've all been fixed in 2.6/NPTL.

One thing I did like was his comment that the distinction between desktops and servers is mostly one of marketing. I thought that was quite insightful, if not entirely original.

Leave Paul alone. (0)

Anonymous Coward | more than 9 years ago | (#11390941)

Paul is dieing a slow death, and he has recently seen that OGrady is doing so much better be taking on OSS. So what is he doing? taking on OSS. Basically, this is his attempt to make a comeback (think of john dovrack for the last 15 years).

His compiler gibberish is...gibberish (0)

Anonymous Coward | more than 9 years ago | (#11391608)

The reason you don't see "one pass" compilers is that the *sequential form of source code* (top to bottom) is not an easy representation to do anything with as far as optimizations go.

That said, for languages without goto it's possible to create SSA form for a program in one pass, and that *is* a useful format for subsequent optimizations. More importantly, for real languages like C/C++ you can still create SSA form in near-linear time.

Hrmph.... "System VR4" (1)

McNihil (612243) | more than 9 years ago | (#11390685)

SVR4 you insensitive clod... no it really matters... also why no word about Amiga 300UX being the first one having full compliance to the SVR4 spec? Also why not wander down the XPG specs... the UNIX95 and UNIX98... and most importantly POSIX... OK yes the article did rub me the wrong way for its lack of reverence I suppose... let it be known that I for one think that just because using linux and OSS in general gives me no right to even try to rewrite history the way big corporations do.

Re:Hrmph.... "System VR4" (1)

McNihil (612243) | more than 9 years ago | (#11390698)

and that would be A-3000UX and not 300... see you made me angry! grrrrrrr.

Best part of the article (1, Informative)

Anonymous Coward | more than 9 years ago | (#11390729)

My request for help included a list of some things you can do with Solaris but not with Linux, and more than 40 readers sent me e-mail responding to this by telling me that Linux (or, in several cases, Windows) can do all of those things [...] those responses suggested a frightening thought for future exploration: that the knowledge gap between the Linux and Solaris communities might be much bigger than I think it is.

The guy's a phony. (4, Insightful)

kma (2898) | more than 9 years ago | (#11390745)

An actual technical comparison between SVR4 and some of its derivatives with Linux would be interesting. However, this guy is utterly incompetent to perform such a comparison. His babblings about the x86 and threads are just word salad. Consider:


Indeed, I'm starting to believe that threading doesn't have a legitimate role in the Intel (Nasdaq: INTC) x86 hardware environment because the hardware defeats the goal of true concurrency between threads -- and if you can't achieve concurrency, what point is there in threading?


Confused? That's what Paul Murphy hoped. He's just as confused as you are. Ignore him.

Re:The guy's a phony. (1)

aluser (771756) | more than 9 years ago | (#11390769)

I wonder if the writer just found out that you can't run processes concurrently on a uniprocessor system. He acts like that's only true for x86.

Re:The guy's a phony. (3, Funny)

ScrewMaster (602015) | more than 9 years ago | (#11390779)

Yeah, well ... this guy is threading water and he's losing ground by the minute.

Re:The guy's a phony. (1)

Neo-Rio-101 (700494) | more than 9 years ago | (#11390784)

I think what he was trying to say was that there's no point putting code to do threading into the OS when there is threading functionality built into the hardware (such as in Intel's hyperthreading CPUs).

But yeah, he really didn't re-edit his article to make that blindingly clear.

Re:The guy's a phony. (0)

Anonymous Coward | more than 9 years ago | (#11390971)

there's no point putting code to do threading into the OS when there is threading functionality built into the hardware

Actually, just the opposite. He is of the opinion that X86 does not thread like Sparcs do. Basically, he is wrong about hardware, and he obviosuly does not understand the use of threads; basically, to prevent a general block when waiting on other resources. If nothing else think how green threads in Java work. They simply are cooperative. This works well for many programs.

Personally, I would say to leave to paul alone. He is pulling an OGrady or Dorvack

I read the FA (4, Informative)

thogard (43403) | more than 9 years ago | (#11390751)

They guy never saw the SVR4 code... talk about a mess. AT&T had nice clean code that worked well was efficient but didn't do networking very well at all. So they hopped into bed with Sun who had real good networking stuff from BSD. The result was the two of them spawned SVR4. The read system call in the old unix was short and sweet and fit on a vt100 screen. The new one took pages even when printed out and didn't do anything new. It was a rewrite for the sake of a rewrite.

There are some very clever things in Unix that you don't notice till someone redoes them and turns them into a stinking heap. For example the new Solaris 10 services. It does what init and inetd does but needs a binary config file which it rewrites on boots and when it changes stuff (ala windows registry for unix). Having been way too deep on too many broken systems, I don't like binary files that change that are essential for my os to work. But this is progress...

Re:I read the FA (3, Informative)

Ungrounded Lightning (62228) | more than 9 years ago | (#11391497)

AT&T had nice clean code that worked well was efficient but didn't do networking very well at all. So they hopped into bed with Sun who had real good networking stuff from BSD. The result was the two of them spawned SVR4. The read system call in the old unix was short and sweet and fit on a vt100 screen. The new one took pages even when printed out and didn't do anything new. It was a rewrite for the sake of a rewrite.

My impression of the SystemV series was that the proprietary status of Unix was in doubt and SystemV was intended to fix that.

Unix was written before the US copyright law was were extended to apply to software, and before the "program as component of patentable invention" hack was invented and debugged. So the only IP protection AT&T had on it was trade secret. Trade secret goes "poof!" when the secret is out, and AT&T had distributed several generations of source and documentation to universities around the world.

(This was also before the breakup of the Bell System, and there was some mandate on them publishing releasing certain telephone-related work as part of their monopoly mandate which, separately, might have imperiled its IP status. I don't recall the details. But it was probably made moot by the court-mandated breakup later.)

Unix had been a back-room project by a team that had been explicitly forbidden, at least initially, from building an OS. (Indeed, one factor driving the kernel's simplicity and the design goal of pushing as much out to the application layer as possible was the creation of plausable deniability: "An OS does X, Y, and Z and this doesn't. So it's not an OS. Right?")

Since they weren't writing something viewed as productizable or proprietary, they were at Bell Labs (where publishing was the usual route for most work), and software in those days wasn't productized anyhow, they felt no need to keep it under their hats.

The broad circulation of source and docs spawned the era of the commodity unix box. A new hardware vendor, rather than writing his own OS, could just port Unix to the box - a matter of hacking a couple thousand lines of hardware-interface code. AT&T would look the other way as long as they weren't selling it. Once they got it working, AT&T would cut a licensing deal on very good terms. (For them it was free money.)

This continued until the University of New South Wales built a course around System 6 (i.e. release 6 of the documentation set, which was how System N was named). They printed a two-volume coursebook - volume 1 being the kernel source pretty-formatted, while volume 2 was a textbook walking you through the guts. This immediately became an underground classic, and finally got onto the administrative radar screen at AT&T. The lawyers "Cease and Desist"ed the University.

The SystemV project, if I recall correctly, started shortly after the CONTU (Committee On New Technological Uses - charged with studying and proposing to Congress whether/how software should receive copyright protection) reported and Congress explicitly extended copyright to cover software. Now that IP protection was available, AT&T got together with several of the big Unix players and together they reimplemented the kernel from scratch, and tried to move everybody to the result.

They gave a number of plausable-sounding reasons for the work - claiming it was a great improvement on the previous stuff. But they didn't include the Berkeley work (especially noticible: no Berkeley Signals) which had its own proprietary issues. The resulting functionality of SystemV was both incompatible with and lower than both BSD and some other System N derivatives. So the general consensus (at least among the people I hung out with at the time) was that the whole exercise was to clean up the IP status of Unix for its future as a product.

Off the top of my head, here you go (5, Informative)

Anonymous Coward | more than 9 years ago | (#11390754)

Here are some obvious differences from someone who's worked on both. These are just some quick things which come to mind, off the top of my head.

1. Streams. ATT's streams was just a mistake. It was a great idea in theory. In practice, it adds too much overhead without enough advantages. Even at Sun, it's recognized among Engineers as a mistake, and it's significant that methods of speeding up the networking stack involve discussions on how to get away from streams.

2. The VM. Linux's VM in 2.6 is vastly superiour to stock ATT VM. And it's probably better than Sun's, in the 2.6 Kernel (NOT before 2.4 however). For example, the VM limitations are one reason why NFS sucks in 2.4 kernels; and even Trond has admitted this.

3. Boot-up code. Grub + Linux rocks. It's the best solution out there. Vastly superious to everything, including Sun's implementation. Of course, Sun is hobbled by that Open Boot nonsense, where you have to type an absolutely absurd amount of stuff to specify a device.

4. kernel debugging. Stock ATT blows here. Sun rules, with Linux becoming a close second. This is with respect to kgdb. Although some new technologies are under development in Linux which are interesting.

5. SMP. Stock ATT blows, but not much has been done lately here. Sun's implementation is superiour to everything, which is why you can support so many processors. Linux is starting to catch up though.

Well, that's just off the top of my head. There are probably other things, but I've got to get back to work. :P

Re:Off the top of my head, here you go (2, Interesting)

carcosa30 (235579) | more than 9 years ago | (#11390950)

Just so you know... best boot manager out there is called Gag. It has no problem supporting whatever operating systems it finds on your disk, and it finds new operating systems AT BOOT TIME.

Re:Off the top of my head, here you go (1, Interesting)

Anonymous Coward | more than 9 years ago | (#11391008)

You are correct on a bunch of this. Apparently, they did internal benchmarking and found that 2.6 was killing them esp. con networking.

In fact, Sun has recently had to re-write major portions of Solaris BEFORE releasing 10.0 to the public. My understanding is that the top ppl spent a lot of time looking at Linux and then "borrowed" ideas.

I find it funny, that when they take ideas, it is borrowing, but when Linux takes ideas, it is theft. Oh, well one groups terrorists is another's freedom fighter.


Re:Off the top of my head, here you go (0)

Anonymous Coward | more than 9 years ago | (#11391025)

With regard to # 5, what about SGI which has 2048 CPUs using Linux in a near Linux scaling. Is Sun better than that these days?

Re:Off the top of my head, here you go (1)

Alien Being (18488) | more than 9 years ago | (#11391053)

AFAIK, the big SGI machines are NUMA, not SMP.

Re:Off the top of my head, here you go (3, Informative)

Anonymous Coward | more than 9 years ago | (#11391560)

First, the biggest single system Linux box is 512 CPUs (although I think NASA has 2048 CPUs in a BX2 machine, which has an expanded cache coherency domain to 1024 or 2048 CPUs, I'm not sure if they've actually hooked them up yet).

Still, that literally blows Sun's biggest machine out of the water. Especially in absolute performance, when you consider a new 9MB cache I2 is probably a clear twice the speed of the fastest of sun's sparcs.

Second, Sun's machines are NUMA as well. That's right, they have Non Uniform Memory Access. See here [sun.com] . They have a 4 tiered access hierarcy on memory. Either way, SGI's NUMAlink interconnect is far better than Sun's old crossbar switch dinosaur. See here [virginia.edu] . The Altix has 4 times the top-of-the-line Sun's memory bandwidth per CPU. That is SGI's old interconnect too, mind you.

Re:Off the top of my head, here you go (1)

thammoud (193905) | more than 9 years ago | (#11391212)

Great commentary. Blows, Sucks and rules. Wow. Great technical insight. A mod 4? /. is sad indeed.

Re:Off the top of my head, here you go (4, Insightful)

idiotnot (302133) | more than 9 years ago | (#11391292)

3. Boot-up code. Grub + Linux rocks. It's the best solution out there. Vastly superious to everything, including Sun's implementation. Of course, Sun is hobbled by that Open Boot nonsense, where you have to type an absolutely absurd amount of stuff to specify a device.

Not. OpenBoot/OpenFirmware are vastly superior to the cheesy i-must-look-like-a-floppy system that crippled pcs have. When grub supports testing hardware, or listing the devices present inside the system over a serial console, let me know. List the scsi busses and the devices present? I've used OpenBoot(sun), OpenFirmware(Apple), the NeXT Rom monitor, as well as the stuff on Alpha and PA-RISC, which I can't remember the names of right now -- they're all much more flexible than grub.

Grub also still doesn't work on all PC hardware. I've never gotten it to work with a Compaq SmartArray card. Never. Several different versions of Grub, several different SmartArrays.

Granted, Grub is a massive improvement over crap like lilo, but it's nowhere near as flexible as what you'd find on a good unix machine.

Re:Off the top of my head, here you go (0)

Anonymous Coward | more than 9 years ago | (#11391417)

damn, i just knew someone would bite on that particular comment...

Re:Off the top of my head, here you go (1)

cortana (588495) | more than 9 years ago | (#11391455)

First of all, you are correct; Grub can't compare to OpenBoot/Firmware, etc.

However, you can list devices present with tab completion. Type root (hd and you will get a list of all your disks. At least the ones that Grub can see through the PC BIOS calls. *shudder*. God knows how you're supposed to boot off a PCI IDE controller, I sure as hell can't.

Re:Off the top of my head, here you go (1)

idiotnot (302133) | more than 9 years ago | (#11391511)

But that just barfs out what's written in device.map, a file that's sitting in /boot/grub. If those devices change and you don't update it...

Or if you want to boot from a device you've just inserted, or you manage to kill the filesystem where grub lived (/me raises hand there)....

PCs have this problem with too much backwards compatibility. The fucked up 1981 boot code perfectly illustrates that. There is absolutely no good reason that a PC built in 2005 should be able to boot DOS. Not one.

Re:Off the top of my head, here you go (0)

Anonymous Coward | more than 9 years ago | (#11391638)

> 1. Streams. ATT's streams was just a mistake.

Have to disagree here. Streams are elegant
and provide a very modular approach to solving
certain kinds of problems. They may or may not
be the most efficient but "efficiency" isn't
the only measure of a good system.

> The VM. Linux's VM in 2.6 is vastly superiour
> to stock ATT VM. And it's probably better than
> Sun's, in the 2.6 Kernel (NOT before 2.4
> however).

Wow... if there is one where Linux *does* have
a weak spot it is the VM. I doubt if it is better
than stock SVR4 and it is definately inferior
to Solaris.

> 3. Boot-up code. Grub + Linux rocks. It's the
> best solution out there. Vastly superious to
> everything, including Sun's implementation. Of
> course, Sun is hobbled by that Open Boot
> nonsense, where you have to type an absolutely
> absurd amount of stuff to specify a device.

This is definately one area in which SVR4
shined. SVR4 had a simple but entirely ef-
fective mechanism for handling kernel booting.
It used a simple, continguous layout filesystem
call the 'Boot File System' or BFS. If you wanted
to install a new kernel to boot the only thing
you had to do was:

mv /boot/kernel /boot/old_kernel
cp new_kernel /boot/kernel

and then reboot your machine. No fuss no muss.
I would really like to see that mechanism make
its way into Linux.

The difference is easy... and surprisingly simple (1, Insightful)

Supp0rtLinux (594509) | more than 9 years ago | (#11390800)

One is completely and totally open source. The other is not.

Re:The difference is easy... and surprisingly simp (2, Insightful)

black mariah (654971) | more than 9 years ago | (#11391200)

And in what way, exactly, does that have a motherfucking thing to do with technical aspects of the OS? Give me that "because it's Free! You can modify it!" bullshit and I'll take a crap on your dinner.

Re:The difference is easy... and surprisingly simp (1)

SpaceLifeForm (228190) | more than 9 years ago | (#11391529)

You are quite correct. Not surprisingly, your post was moderated 'Redundant'. Not surprisingly, your post was the first to point out the difference in licenses. Not surprisingly, the astromods are out in force.

Euh? (2, Funny)

Anonymous Coward | more than 9 years ago | (#11390832)

I'm not a native english speaker but does anybody can make head or tail of whatever he says?

On the other hand he seems a credible source of insight, being the author of the best seller "The Unix Guide to Defenestration". That my friends is a book I missed, somehow. Here's the beginning of the blurb for the book:

This book explains that most commercial systems work disappoints because the incentives favor exactly the kind of continuous low level failure we usually see. Systems management careers are enhanced by budget growth and staff expansion, both of which are maximized by maintaining a level of non performance that teeters on the edge of catastrophe. Correspondingly, systems budgets and staffing levels, and therefore management careers, are diminished by successful execution of the cost reduction, or cost avoidance, mandates that normally go with the job.

Maybe it's just me...

Re:Euh? (1)

Ungrounded Lightning (62228) | more than 9 years ago | (#11391597)

On the other hand he seems a credible source of insight, being the author of the best seller "The Unix Guide to Defenestration".

The book is NOT a how-to about using Unix as a tool for completely purging Windows from your IT operation. He grabs the term "Defenistration" and defines it to mean something else - something unrelated to windows. So IMHO a significant part of the book's reason for existence is to co-opt the word and the book title.

Yup (0)

Anonymous Coward | more than 9 years ago | (#11390881)

The author of this piece is an idiot. Why anyone would pay him to write about computers isn't beyond me though. Seems like most of these computer journalist types are hopelessly dense. Their chief talent seems to be writing countless paragraphs about how ignorant they are.

In other news today (1)

donnz (135658) | more than 9 years ago | (#11390900)

ASDA boxer shorts are very similar to those sold in Tescos...

I mean, no shit, OSs doing similar things, what an insight.

Comparing Linux to SVR4 (1)

yorugua (697900) | more than 9 years ago | (#11390943)

what??? I mean, sccs, you know... I kind of miss "what".

The GPL is Linux's hallmark (4, Insightful)

andrel (85594) | more than 9 years ago | (#11390946)

What can you do with Linux that you couldn't do with SVr4 in 1992? Freely share the source with all your friends and customers without fear of lawsuit and include pre-installed binaries on hardware without paying royalties. GPL licensing is the single most important feature distinguishing Linux from proprietary kernels such as UNIX and other free kernels like the BSDs. The GPL's copyleft provision and the dual-licensing opportunity it creates are why companies like IBM and SGI have contributed subsystems like JFS and XFS to Linux. They wouldn't have shared the same code under a BSD license. Linus has said that choosing the GPL is the best decision he made in the early days.

Reasons to use threads on uniprocessor x86 (5, Informative)

pslam (97660) | more than 9 years ago | (#11391087)

He's obviously quite unqualified to write the article and didn't even bother to ask anyone. A single processor can emulate multiple processors, and this is often a convenient and even efficient programming model. To elaborate:
  • Sometimes it's cheaper in memory and/or clock cycles to use context switching and multiple stacks than scheduling functions off a single thread. This can be true even if the threads aren't concurrent (e.g coroutines).
  • It's often easier to use multiple threads even when not necessary, despite having to deal with mutexes. The amount of state in some protocols can lead to a mess.
  • When you need low latency, threads are often the only solution.
  • Single threaded apps cannot schedule tasks preemptively. Reason enough right there.
  • If you need prioritisation of preemptive tasks. When you do, the kernel is best off doing the scheduling because you might not be the only process with priority needs.
  • A thread is just a process without most of the baggage, and you don't see people arguing that processes don't belong on x86.
Then again, mindless use of threads does annoy me. So I'll list some "soft" indicators of when you shouldn't use threads:
  • When a single threaded app would be substantially faster.
  • When you don't need preemption.
  • When you're going to be using 8,000 of them. It's at least 4-16KB per thread, and thread switches aren't negligably cheap. Rewrite with poll().
  • When you cannot say with certainty that you won't deadlock or race.
  • When you don't understand what the previous point means.
  • When your hardware/OS/platform has a hideous thread switching cost. Can't think of any reasonable system these days where this is a show stopper.
Leave criticism of OS features to those who are qualified, Murphy. Better still, try asking one of them - there's no shortage.

Linux Concurrency (1, Interesting)

Anonymous Coward | more than 9 years ago | (#11391101)

I'm not sure what the kernel has to do with it. The point of achieving concurrency is to avoid kernel entanglement. That means lock-free programming where possible. How successful you are there depends on the hardware architecture and who's supporting lock-free programming. As someone who's doing the latter (Atomic Ptr Plus [sourceforge.net] ), it's not likely I'm going to get ahold of a Niagra processor based system (and I'm going to dump my SB100) so you won't see too much there. However, I am going to get a Mac Mini, so you will see support for Darwin as well as Linux.

Why is it that slashdot can never.... (0)

Anonymous Coward | more than 9 years ago | (#11391161)

Talk about technology along with both pros and cons. Why is everything so religious and arguments are based on policy rather then technology.

We can all learn from everyone, even if we can't see their source code! Inovate rather then immatate.

why (1)

suezz (804747) | more than 9 years ago | (#11391300)

he doesn't need any help - he seems to have figured everything out himself - System V is great and "enterprise ready" and linux is nothing but a toy. he is a troll just fishing for SCO I bet - last thing I would do is help this joker -

VR?! (1)

adriantam (566025) | more than 9 years ago | (#11391431)

System V Release 4 has nothing to deal with virtual reality. Please write it as System V R4 but not System VR4.
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