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Linus And Alan Settle On A New VM System

timothy posted more than 12 years ago | from the imagine-this-was-about-windows-developers dept.

Linux 167

stylewagon writes: "ZDNet are reporting that Linus Torvalds and Alan Cox have finally agreed on which Virtual Memory manager to include in future kernel releases. Both have agreed to use the newer VM, written by Andrea Arcangeli, from kernel version 2.4.10 onwards. Read more in the article."

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Slashdot Troll Awards 2001! (-1, Troll)

Slashdot Troll Award (534847) | more than 12 years ago | (#2532289)

It has come to my attention that many years of constant moderation and sexy, sexy metamoderation have caused many of you to develop a brainwashed state that causes you to gain a small sexual thrill from the act of voting. I'm not saying this isn't something for you all to be ashamed of; frankly, I think you're all a bunch of twisted fucked-up weirdos. I know you were all jacking off in voting booths for George W. Bush, and I know that the three months it took to bring that election to the correct conclusion brought you all as close as you'll ever get to a female orgasm, both conceptually and in terms of physical proximity.

It's time to put your sick voting perversion to good use. It's time for the Slashdot Troll Awards 2001! Slashdot's answer to the emmys, grammys and the eurovision song contest. This is the night when slashdot's most renowned personalities gather to do honour to their own. Wouldn't you like to brush shoulders with the likes of Ralph JewHater Nader? Or slashdot teen-idol SumDeusExMachina?

Here's your chance. One lucky winner will be selected to spend a day with some of slashdot's most glamourous celebrity trolls, in the new SECRET TROLL SID! Could you be the lucky winner? There's only one way to find out!

How To Vote:

To begin, simply fill out the form below, giving the name, and if possible, link to the troll you consider most deserves to win the category. Vote in as many or as few categories as you like! Vote as many or as few times as you like! Since this is an internet poll, ballot stuffing is both valid and encouraged.

All candidates except those for the Hall of Fame category must have been present and active on slashdot between November 6, 2000 and November 6, 2001, give or take.

Email your completed form to slashdottrollawards@ziplip.com from whichever web mail account you use to conceal your real identity, and protect yourself from ever being connected to the horrible, spiteful, juvenile things you do online.

Winners will be announced whenever I feel like it. If VA Linu...excuse me, VA Software goes under and takes slashdot with it, before I get around to counting votes, winners will be announced on a website with a sensible business plan [geekizoid.com].

The Categories!

  • Best Troll Post in 2001:
  • Best Crapflood in 2001:
  • Best First Post in 2001:
  • Best Ongoing Character Troll in 2001:
  • Best Flamewar of 2001:
  • Best Biter in 2001:
  • Best Troll Account of 2001:
  • Best Crapflooder of 2001:
  • Most Dedicated First Poster of 2001:
  • Most Impressive Editor Response to Trolling in 2001:
  • Best Troll Song of 2001:
  • Best Impersonator of 2001:
  • Most Inflammatory Response to a Jon Katz Article in 2001:
  • Most Heartless Response to 9/11 Tragedy in 2001 (Category open this year only):
  • Most Convincing Attack on Michael Sims in 2001:
  • Best Trollslap of 2001:
  • Wanker of the Year
  • Hall of Fame Inductee:

vm (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2532290)

first vm post!

w00t!

my vm is the best!

mcdougal

sensation seekers (5, Informative)

selmer (37218) | more than 12 years ago | (#2532299)

There never really was a big dispute about the VM subsystem, read alan's diary [linux.org.uk] for an account of what happened in his opinion.

I cite November 2nd: The great VM dispute really isn't. It went something along the lines of "Putting a new vm in 2.4.10 is crzy", "Probably it was but its done so lets make it work" and at 2.4.14pre8 "See it works" "Yep".

Re:sensation seekers (3, Offtopic)

hconnellan (31637) | more than 12 years ago | (#2532624)

Read about the big news on 5/6 Nov. Alan is installing windows. Alan's diary [linux.org.uk]

Final Nissan VP agrees to stop calling it Datsun (1)

Unknown Bovine Group (462144) | more than 12 years ago | (#2532685)

I didn't see the lowercase w. I wouldn't be surprised if Microsoft's marketing picked up on this and used it. :D

Seriously though. This 'news item' is roughly akin to "Final Nissan VP agrees to stop calling it 'Datsun'".

Re:sensation seekers (4, Funny)

Gleef (86) | more than 12 years ago | (#2532727)

And people say it's easy to install windows. Two days and there's still more work to do.

good news (2, Insightful)

Psychopax (525557) | more than 12 years ago | (#2532304)

Though I do not think that Linux would have been doomed just because there were two different versions of the kernel out there it would have been probably more difficult for Linux.
So that's good news. J.

2.5.0, here we come! (-: (2)

leonbrooks (8043) | more than 12 years ago | (#2532437)

...and not before time. Perhaps Linus can make a firm decision by, say, 2.5.10 on what goes into 2.6 and what gets kept aside for 2.7? That way we might see 2.6 before the end of 2002. We can always hope.

It's important for a lot of this new stuff to get thoroughly used so that alternatives, replacements, options and enhancements can be devised at warp speed. It's also important to have an odd kernel series active so that imaginitive new stuff has a home and doesn't stagnate.

Re:2.5.0, here we come! (-: (0)

neroz (449747) | more than 12 years ago | (#2532523)

That way we might see 2.6 before the end of 2002.

You must be joking. I'd expect a 2.6 near the end of 2003 or start of 2004 - 2.4 should last a while IMHO, and they can hack away on 2.5 and make a good [and stable] release for 2.6.
Personally, I dont think 2.4 should have been released when it was, so you can think of 2.4.14 as 2.4.0pre14 [heh].

Re:2.5.0, here we come! (-: (0)

Anonymous Coward | more than 12 years ago | (#2532883)

I still have fond memories of Slackware and the 1.2.13 kernel.

Silly me.

Re:good news (1)

tshoppa (513863) | more than 12 years ago | (#2532742)

Having a single unified kernel source is, IMHO, not a worthy goal. The biggest advantage to an open-source kernel is that you can go in and tinker with it; having multiple folks pursue multiple tacks to VM is not in itself bad.

There are other "branches" off the kernel tree for real-time kernels, etc. Getting rid of these would not be "good news".

NUMA?! (5, Informative)

ssimpson (133662) | more than 12 years ago | (#2532307)

It's previously been argued that Andrea's VM doesn't work with NUMA architectures, hence work should continue on Rik's 2.4.x design

Not a problem now, but it's one of the major aims of 2.5, according to Linus. Anyone know how they are going to square this circle?

Re:NUMA?! (4, Insightful)

Prop (4645) | more than 12 years ago | (#2532348)

I have to ask ... shouldn't a NUMA-efficient VM be left as a patch, or thru a kernel fork ? I mean, how many people have access to NUMA machines, let alone own one ?

The VM in the mainstream kernel should be optimized for what Linux runs on 99% of the time : single CPU, with a "standard" memory bus.

With that being said, I couldn't believe that Linus made such a major change in a stable kernel. I'm glad it works, and that Alan Cox has agreed to go with it, but it wasn't an example of software engineering at its finest...

Re:NUMA?! (2, Insightful)

Anonymous Coward | more than 12 years ago | (#2532602)

but it wasn't an example of software engineering at its finest...

In the strictest sense... you are correct. However, engineering of any sort is a real world activity, not some dry academic subject (Wirth is full of shit on many topics, for example). Knowing when it's time to give up on a bad job, chuck it out and give something else a chance is a valuable thing (but not something to do lightly, or often).

Re:NUMA?! (1)

Nicopa (87617) | more than 12 years ago | (#2532763)

And I'd like to add that the fact that the VM worked fine from the very start, and Alan's choice to switch to it shows that Linus is capable of taking these decisions. Perhaps he shouldn't have been so second-guessed.

Re:NUMA?! (1)

led (3096) | more than 12 years ago | (#2532930)

Actualy I had some problems with it, on a few of my web servers, when the load was high a mem low....
2.0.x,2.2.x,2.4.x kernels are suposed to be safe... the 2.4.x broke this... I don't think I will trust installing a new kernel like I used to...

Re:NUMA?! (1)

Anonymous Coward | more than 12 years ago | (#2532979)

If you install the most recent kernel release (stable series or not) on a production box, you are a fool. No two ways about it, and it's never been any different.

I only install kernels from Redhat (they've been throughly stress tested) on important boxes. I take risks with non-essential machines.

Re:NUMA?! (4, Informative)

Alan Cox (27532) | more than 12 years ago | (#2532349)

Getting NUMA to work well with Andrea/Marcelo's VM might be more interesting. On the other hand Martin and the other IBM folks don't seem duly perturbed on list so I'm not that worried

Re:NUMA?! (2, Insightful)

Ed Avis (5917) | more than 12 years ago | (#2532544)

I'm currently wondering about NUMA - or something close to it. I'm running Linux on a couple of machines where the memory is of differing speeds: a fast eight megabytes and then the rest of the RAM is a lot slower. Can existing Linux kernels handle that sensibly?

Re:NUMA?! (2)

Sneakums (2534) | more than 12 years ago | (#2532610)

I'm running Linux on a couple of machines where the memory is of differing speeds: a fast eight megabytes and then the rest of the RAM is a lot slower. Can existing Linux kernels handle that sensibly?

One way might be to configure the slow RAM as a ramdisk and use it as swap.

Re:NUMA?! (1)

Ed Avis (5917) | more than 12 years ago | (#2532650)

One way might be to configure the slow RAM as a ramdisk and use it as swap.
I considered that, but it's a lot of overhead pagefaulting and going through the VM system and ramdisk driver every time a page is needed from outside the eight fast megabytes. It works fine to run processes using the memory above 8M, it's just slower. So I'd like Linux to somehow 'prefer' using the lower pages of memory and maybe rearrange things occasionally so that the more frequently used pages are kept in the fast RAM.

Re:NUMA?! (-1, Troll)

Anonymous Coward | more than 12 years ago | (#2532748)

if you're using linux, you're obviously not concerned with speed.

Now go back under your bridge, troll.

More information is available: (3, Offtopic)

ssimpson (133662) | more than 12 years ago | (#2532318)

At eWeek. [eweek.com]

Re:More information is available: (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2532507)

Man, put a fscking <br> or <p> before your sig. That is so annoying.

Agreed? (-1)

Andy (2990) | more than 12 years ago | (#2532319)

I am a little puzzled that Alan has any final say in the matter. Linus is widely acknowledged as the final arbiter of what features the new kernel contains. Why should he kowtow to Alan or anyone else? Does Alan's increased stature come about because he is threatening a Red Hat fork?

This article is a joke... (3, Offtopic)

Juju (1688) | more than 12 years ago | (#2532320)

It claims that SuSE is a US company (funny how I could have sworn it was German ;o)
It also says that Alan Cox will take over 2.4 once 2. 5 is opened which is wrong...

The whole war story is totally ridiculous. There has never been a talk about a fork. All there was were discussions of whether a new VM should be brought in 2.4 instead of 2.5, and some talk about the validity of benchmarks showing the improvements with the new VM.

I guess there is not much going on in the news for them to feel like writing about this...
Besides, this is nothing new since Alan Cox sayed that his last ac patch would probably be the last one with the old VM.

Re:This article is a joke... (4, Informative)

Syberghost (10557) | more than 12 years ago | (#2532396)

It also says that Alan Cox will take over 2.4 once 2. 5 is opened which is wrong...

Just in case somebody doesn't believe you, here's the proof [advogato.org].

Re:This article is a joke... (3, Informative)

dangermouse (2242) | more than 12 years ago | (#2532803)

It claims that SuSE is a US company (funny how I could have sworn it was German ;o)

Just for the record (I've pointed this out elsewhere), SuSE Inc. is a U.S. company... SuSE has done the general equivalent of incorporating in several countries, including the U.S. SuSE Inc. is, in fact, in Oakland as the article reports.

Of course, it might not be SuSE's U.S. corporation that's involved here, but that's a completely different possible source of inaccuracy. ;)

In related news... (5, Funny)

Oshuma.Shiroki (232199) | more than 12 years ago | (#2532322)

Linus Torvalds and Alan Cox have finally agreed...

In related news, pigs are now flying all over town, and hell just froze over.
</sarcasm>

WCHC (-1)

Guns n' Roses Troll (207208) | more than 12 years ago | (#2532323)

If there are any folks in the Worcester MA area, WCHC 88.1 is a pretty good college station. They play some pop-punk and the DJs aren't watered down commercial fucktools.

WBRS (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2532655)

Fuck that shit... WBRS 100.1 Waltham is where it's at.

why not just say linux almost contracted anthrax! (1, Insightful)

mark_lybarger (199098) | more than 12 years ago | (#2532327)

from the article- The accord also ends speculation that a fragmented Linux community would be doomed in the face of Windows.


where does this ludicrious speculation come from? this sort of reporting of unsubstanciated claims is quite funny on the surface. but the more general audience reading this article will think MUCH less of the stability of the linux kernel reading crap like this. sure there is/were two different VM systems that has caused lots of posting here on ./ and probably much discussion on the kernel mailing list. how in the hell does that indicate that the linux community will be doomed in the face of windows? ARRRGGGGG!

Re:why not just say linux almost contracted anthra (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2532369)

Bill Gates: "All your Virtual Memmory are belong to us!"

Was there really any "dispute"? (3, Insightful)

sphealey (2855) | more than 12 years ago | (#2532333)

Was there really any dispute between ac and Linus, or was it just a technical competition to see which system could be pushed the farthest?

I thought the eWeek article took an unnecessarily confrontational tone.

sPh

Re:Was there really any "dispute"? (2, Interesting)

nyteroot (311287) | more than 12 years ago | (#2532907)

yeah, plus the gross inaccuracy saying alan was going to maintain the 2.4 kernel.. didnt they *just* announce that it would be marcelo? oh the joys of clueless linux reporting..

Really glad to see this happen (2, Flamebait)

tannhaus (152710) | more than 12 years ago | (#2532334)

I was talking to a friend yesterday about this very issue. I'm glad to see it resolved. To the outside world, Linux already looks fragmented compared to windows (many different distributions of linux compared to one Microsoft). This may not be a correct assumption, but having two different kernels did not help the situation at all.

Now, finally, we can say again : "There is one linux kernel, there are many different distributions. The kernel is the same and the different distributions differ only in programs and scripts".

Linux isn't ready for the desktop? Ohhhh crap....do I have to erase it then?

Re:Really glad to see this happen (0)

Anonymous Coward | more than 12 years ago | (#2532454)

Except that's not true. Alan wasn't keeping his own tree just because of the VM. He's been doing so for a long time. Alan's tree is where more 'experimental' things go for testing, etc, before Linus puts them in the main tree. Alan will, undoubtedly, keep doing ac (at least when 2.6 comes out, I assume he'll be doing a lot with 2.5 now). This was just a highly publicized 'rift' in the two kernels.

Re:Really glad to see this happen (0)

tannhaus (152710) | more than 12 years ago | (#2532934)

I understand that part..but when the official kernel came out, didn't ac use it, then add new patches to it? patches that would eventually make it into the official kernel?

so 2.4.5-ac1 was the 2.4.5 kernel with these changes..

?

Re:Really glad to see this happen (1)

gmack (197796) | more than 12 years ago | (#2532663)

That's not actually correct.

Right now we have 3 kernel trees being sepperately
maintained: 2.0.38, 2.2.20, 2.4.14 are all diffrent trees.

Forking happens all of the time and it's in general a good thing if done right. People were making much too big a deal out of this.

flamebait?! (0)

tannhaus (152710) | more than 12 years ago | (#2532917)

How in the world did my original post constitute as flamebait??

That's just too weird..had to say something

In other news (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2532340)

Israel and Middle East sign final peace agreement
Taliban give up Osama bin Laden
Slashdot Trolls set on fire by God.
LINUS AND ALAN COX AGREE ON NEW VM SYSTEM

Which one of these headlines is most important?

Re:In other news (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2532572)

Israel and Middle East sign final peace agreement

Isreal and the entire Middle East eh? Wait, isn't Isreal in the Middle East?!

Isreal and Palistine would be correct, dirt for brains. They say Americans have no idea whats in the outside world, there is the proof.

So what? (0)

CMBurns (38993) | more than 12 years ago | (#2532360)

Does this really matter to the average Linux user in daily life? I've been using Linux for several years now and never stumbled upon some obscure VM (besides Java VMs, but that's another story). It just used to work, and it worked good.

So what's this all about? How does the average user profit from this change? Maybe Linus was right when he stated that the really important/interesting work is now done on the desktop frontier and no longer under the kernel's hood.

Any suggestions?

Re:So what? (1)

afinn (467407) | more than 12 years ago | (#2532392)

Dont mean to be pedantic but VM here is virtual memory. The java VM is virtual machine. Quite different. Your average linux user doesn't need to know about the virtual memory system. But if your programming java, you should have an idea how the java VM works.

Re:So what? (4, Informative)

stilwebm (129567) | more than 12 years ago | (#2532536)

For one, the new VM is less likely to begin killing processes or swapping randomly. Also, the new VM works in a more simple (relatively speaking) way that uses about 1/2 the swap space as the previous 2.4 VM. Like the VM system in 2.2.x kernels, having 128MB of RAM and a 128MB swap file will result in about 256MB of virtual memory available to the system. In the previous 2.4.x VM system, a computer with 128MB of RAM needed 256MB of swap space to effectively use 256MB of virtual memory.

SuSe in Oakland... (2)

AndroSyn (89960) | more than 12 years ago | (#2532361)

It seems these folks decided that using the whois database for the companies location was a good idea.

It turns out that the registration for suse.com does point to an office in CA. But if this moron would do some real research, he'd find out that they are infact in Germany. Of course all of us knew this.

Then again most reporters are morons..

Re:SuSe in Oakland... (0)

Anonymous Coward | more than 12 years ago | (#2532595)

But if this moron would do some real research, he'd find out that they are infact in Germany. Of course all of us knew this.

Or maybe, in the spirit of patriotic fervor, EVERY GOOD THING IS NOW MADE IN THE U.S.A.?

Re:SuSe in Oakland... (1)

dangermouse (2242) | more than 12 years ago | (#2532781)

SuSE, Inc. (SuSE's United States corporation) is in fact located in Oakland. Unless it's one of the other SuSE companies in another country that's paying the man, they got it right.

Make your words less bitter... that way when you eat them later it won't suck so much.

Re:SuSe in Oakland... (2)

LizardKing (5245) | more than 12 years ago | (#2532940)

Last time I read lkml, Andrea's e-mail address was a .de one, which suggests that he works for the parent company in Germany.

the way i heard it was resolved was... (4, Offtopic)

motherhead (344331) | more than 12 years ago | (#2532364)

Linus and Alan had their wrists taped together and sort of danced/knife fought while eddy van halen played guitar in the background...

oh wait that was a michael jackson video... sorry... though still this might be as accurate as anything else...

Good news. (2, Interesting)

rmadmin (532701) | more than 12 years ago | (#2532367)

Regardless of what the article almost implied (that Cox and Linus were at dispute), this is good news for the kernel. From the sounds of it this new VM will make quite a difference from a performance aspect. I could almost care what people are fighting about. As long as new features get implimented, or the system is revamped to improve performance/stability, I'll be happy. And thats what the point is here... A new VM is going to be implimented, and its supposed to kick butt. So enjoy it and quit squabling about weather or not Cox and Linus are fighting!

Summary as I see it... (5, Insightful)

Duncan Cragg (209425) | more than 12 years ago | (#2532378)

1. Everyone knew the Rik VM was poor
2. Linus was stressed about it and took a brave decision to go with Andrea's VM
3. It was VERY late to be doing this, but necessary.
4. Linus' decision was correct as it turns out.
5. Alan's decision was also correct in that you shouldn't be doing this kind of dramatic about-face in a 'stable' kernel.
6. Alan's going with Andrea was also correct.
7. I've been waiting, along with many others, for this whole mess to be sorted before 2.5 was started and I upgraded kernels.
8. Passing 2.4 over to Alan means we can upgrade in confidence. This should be the test of stability for 2.6: upgrade when Linus passes it on to Alan.

The Days of Our Kernel (5, Funny)

rnd() (118781) | more than 12 years ago | (#2532379)

Posting dramatic stories about the heated debate among supergeeks in the Kernel newsgroups is a brilliant propaganda tool.


What better way to insure the longevity of Linux than to recruit new Kernel Hackers with tales of heated debate and intrigue (I've noticed two in the last week).


What's next, the KernelCam? Tune in to watch Linux, Alan, and the rest hacking away. View live feed of USENET postings! Only $3.99 per minute.

Re:The Days of Our Kernel (0)

Anonymous Coward | more than 12 years ago | (#2532667)

What's next, the KernelCam? Tune in to watch Linux, Alan, and the rest hacking away. View live feed of USENET postings! Only $3.99 per minut

Didn't Bill Gates^h^h^h^h^h^h^h^h^h^hTim Robbins have something like that in 'Antitrust'?

Strength of our style of development (5, Insightful)

gaj (1933) | more than 12 years ago | (#2532381)

This just further illustrates the strength of an open development process. There was a problem, and that fact was discussed openly and pointedly. That scares many people. I don't get why. It's code, not a person. It doesn't look like Rik is taking it very hard, at least as far as his posting on lkml shows.

I like to think of Linux development as sort of a modified IETF style: rough consensus and running code, with a sprinkle of holy penguin pee when Linus thinks it's ready to ship. Linus saw a problem, had a solution presented to him, and just went for it. Alan thought it was a bit insane to switch horses in midstream. I would normally agree with Alan; better to try to get the horse you're on to do the job than try to jump to another one. Worry about getting a newer, better horse once you're safely on the other bank.

Given the time frame for 2.5/2.6, though, and given the seriousness of the VM issues, I can see why Linus decided to take the risk. Apparently so does Alan. I'm kindof anal about release numbers, so I'd probably have started a 2.5 branch to test the new VM in, and refused any other changes, then released 2.6 with the new VM. That fundamental a change should probably get a point increase in version number.

Regardless, the short version is that this is much to do about nothing. The rest of the industry just isn't used to seeing this sort of thing happen in plain view. It normally happens behind the scenes, with a carefully scripted spin put on it by marketing. Maybe if they see the process work enough times people will become comfortable with it. I doubt it.

Holy Penguin Pee (2, Insightful)

Bonker (243350) | more than 12 years ago | (#2532958)

I like to think of Linux development as sort of a modified IETF style: rough consensus and running code, with a sprinkle of holy penguin pee when Linus thinks it's ready to ship.


This is perhaps the most beautiful description of the process I have ever heard.

I agree with you. People are used to dealing with a companies like MS, Apple, and Oracle, who are built from the ground up to never admit deficiency or the need for change even though that is a crucial aspect of any kind of upgrade cycle.

When a group of firebrands come around that can freely admit deficiency, it does cause some waves.

Between a rock and a hard place (3, Informative)

renehollan (138013) | more than 12 years ago | (#2533024)

Oh, it is SOOO tempting to patch what you know, rather than start over with something new, and relatively untested, espescially when deadlines loom.

Of course, this might not fix the problem: either the patch doesn't fix enough, or the design is flawed to start with (I have not delved into either Linux VM to competently present an opinion here, just speculation on what might be wrong). But there is something to be said for "the devil you know". At least the problems with the old VM were fairly well known. Moving to a new VM could potentially introduce new ones. Not something you want to do close to release.

Now, those plagued by problems with the older VM might, in exasperation, think anything would be better. Enter Linus with Andrea's alternative: "looks good, ship it!" [my paraphrasing]. Those of us who'd tremble at the thought of new, untested code, could, well, stick to an older kernel, even if it meant giving up some new features.

But wait! It's Alan to the rescue!! Picking up all the relatively easy fixes and enhancements, and giving me a choice. Leave the contentious parts till later..

It strikes me that the minor, temporary -ac fork served both camps of users until the issues were resolved.

Some might argue for a more disciplined approach, and not make major changes so close to release. (But, if it isn't "ready", why not just postpone release? Is Linus feeling pressure to release prematurely? Or just trying to release "often enough".) But that stands in the way of progress -- I've seen managers crippled by fear of changing anything. Sometimes you gotta take a chance, even if some things break while (many) others get fixed.

While smaller, digestable kernel changes might be more palatable, they're already available in interim development releases. Sometimes a change is sufficiently profound that it touches everything (yes, that's an argument to refactor, but hindsight is 20/20, so I won't argue that point too much) and takes a while.

I am not one to say which approach is globally better -- I can only comment on what works better for me. I can say, though, that when a community is really split over a course of action, and any single choice will not satisfy a large number of people, a fork, even if temporary, is probably the least painful route in the short term, even as the long term consequences are undesirable if it goes on too long.

After all, all progress is a mini-fork from "stable" to "untested".

Details please (4, Interesting)

lythari (118242) | more than 12 years ago | (#2532384)

how does this new VM manager compare to the old one? I assume it's better, but exactly how does it improve over the old one.

And how does it compare to VM manager in other 'nixs out there, especially FreeBSD.

Re:Details please (1, Flamebait)

Tsk (2863) | more than 12 years ago | (#2532419)

Yes Please compare with what's supose to be the best *BSD implementation, NetBSD's one.

Re:Details please (0)

easter1916 (452058) | more than 12 years ago | (#2532631)

"L'histoire est nôtre elle est l'oeuvre des peuples"


I think you need a comma or a period after "nôtre".

Re:Details please (3, Informative)

Anonymous Coward | more than 12 years ago | (#2533017)

They both had stability problems at 2.4.10. Both are fairly stable at this point.

Rik's VM is considerred "smarter." It works harder to balance things out and keeps track of all kinds of info.

Andrea's is not very well documented.

Andrea's is simpler.

Andrea's uses "class zones" which are not good for NUMA. We want to have NUMA in 2.5.

Andrea's is faster.

Linus is considerred the leader and Alan Cox is considerred the second in command. If it's a really tough call to make then probably going with Linus is the less contraversial thing to do.

When Linus switched VM's we had gone through 10 point releases of the kernel and the VM still wasn't as stable as it should have been. If Andrea's VM took 10 releases to become stable then that would have sucked. A lot of people pointed this out to Linus in a blunt way. People thought it might take nearly that long but it only took 4.

So it worked out in the end.

ZDnet is not the ACM (5, Insightful)

Kefaa (76147) | more than 12 years ago | (#2532399)

We seem to take things too personally here. Alan and Linus had a disagreement about when and why. Much like people I work with on a daily basis have differences of opinion on approach. In the end we do not start working for other companies, we reach an agreement.

ZDnet is not the ACM; they are trying to sell magazines (or at least sponsors). A little conflict spices up the story. Should they put a more reasonable context around these things? Sure. However, if they did : "Linus and Alan agree on future" is hardly news worthy.

The more people hear about LINUX the better. (positive spin coming...)

In this context people can believe we know how to operate as open source and an effective business model. The need to evaluate, compare and when necessary compromise can be accomplished in this model for the benefit of everyone. People who appreciate that the people we want to be making business decisions for Linux.

Open Source vs Corporations (5, Insightful)

darkov (261309) | more than 12 years ago | (#2532401)

I think it's unfair to characterise robust debate as fracturing or a lack of unity in the Linux comunity. Isn't it normal for people to disagree on things? It may look like disunity to your average joe, but the fact is that corporations very carefully control what the media knows and what discussions go on behind closed doors. I'm sure everyday people in companies all over the world not only argue till they are blue in the face, but also undermine each other's authority, turn coworkers against their opponent and other nasty political bullshit.

Open software has an open process. That is a strength. Suggesting that just because there is disagreement in the Linux community means that it is less co-operative or cohesive than Microsoft or anyone else is utter crap. Open debate and having your own opinions are healthy signs, much better than some coerced worker toeing the company line, idependent of what is technically best.

Yeah! (5, Funny)

Greyfox (87712) | more than 12 years ago | (#2532527)

In a company, you can't just come out and call your manager or a member of your programming team an idiot. That tends to get you fired, usually. Even if they really are an idiot (Generally, or about one decision in particular.) In the open model, you call someone an idiot and the community decides who the idiot is.

I haven't been following this thing closely but my impression from this forum was it went something like this:

Alan: You're an idiot!
Linus: You're an idiot!
Alan: Fine! I'll take my kernel and go home!
Linus: Fine! I'll get someone else to do the kernel!
Later...
Alan: Linus, you bitch! Have you been seeing another kernel developer on the side?
Linus: Yes, but I was a fool! I love you! I've always loved you!
Alan: And I love you!
Linus: You're not an idiot!
Alan: Oh, Linus! (Kiss kiss kiss)
Linus: Oh Alan! (Kiss kiss kiss)
Linus: Oh! Alan!

Hmm. Maybe I've been reading too many romance novels lately...

Re:Yeah! (2)

bgarcia (33222) | more than 12 years ago | (#2533016)

In a company, you can't just come out and call your manager or a member of your programming team an idiot.
Heh. You haven't been a member of the work force for very long, have you?

Re:Yeah! (1, Offtopic)

SubtleNuance (184325) | more than 12 years ago | (#2533052)

Hmm. Maybe I've been reading too many romance novels lately...

What? You read romance "novels"?

Ill be reporting you to CommanderTaco for proper reeducation if this is confirmed. We will have to confiscate, and burn of course, every romance "novel" you own and re-issue you a library of SciFi proper... do not dispare commrade - THERE IS HOPE FOR YOU YET!

Embrace & ... (0)

Anonymous Coward | more than 12 years ago | (#2532405)

The new VM has been embraced, is it now time for the extending-part?

Media perception of Linux (2, Interesting)

Count (107594) | more than 12 years ago | (#2532410)

Its so funny how everything that goes on in the Linux community that is reported on, even by "tech-sauvy" news orginizations, has to do with the doom and gloom of Linux. It seems that almost weekly Linux is narrowly "saved" from total destruction. I think the media wants people to believe that Linux is so unstable and that the smallest dissagreement will seperate the whole community and send it into complete chaos.

..."The accord also ends speculation that a fragmented Linux community would be doomed in the face of Windows."...

It seems that news about Linux is not intresting enough unless it is a struggle against Microsoft or has some doomesday issue that could cause it to "fall".

just an observation ... I would just like to see a news article that didn't mention the "unknown future" of Linux

one heck of a daily commute: (4, Offtopic)

Bazman (4849) | more than 12 years ago | (#2532415)

"Cox, who also works for Red Hat, in Durham, N.C., and lives in Swansea, Wales."

Stable & reliable VM design PSE! (0)

Anonymous Coward | more than 12 years ago | (#2532422)

I just want to have the most stable && reliable VM design. I couldnt believe when I switched to 2.4.1 and had so many problems with the VM. Also I remember strange comments from Linus saying that you had to have twice the swap space of RAM, which is incorrect, as the VM is supposed to start been used when you havent enough RAM (am i wrong ?).

I think they made a mistake releasing a buggy VM design in a stable kernel serie (2.4), which was solved just with the beginning of 2.4.10 series.

Hope to not suffer never again this behavior. I dont care if is they choose Andrea Arcangelis or Riks VM design but please keep working on it, its a major concern for an OS that claims to be stable & reliable (I dont want to switch to *BSD).

Kind Regards.
jc.

What is a vm? (2, Troll)

Manes (17325) | more than 12 years ago | (#2532428)

Anyone care to give a short explanation on what this system is?

I've always been interesting in kernel coding, but some of the concepts sound pretty black-magic for me :)

Re:What is a vm? (0, Troll)

Isle (95215) | more than 12 years ago | (#2532649)

In case you dont know:
You REALLY dont want to know!! Just enjoy or go back to Windows ;-)

virtual memory (5, Informative)

Lethyos (408045) | more than 12 years ago | (#2532741)

In brief and ONLY the basics... Modern operating systems today handle memory addressing in a virtual sense so that "fences" can be placed around memory owned by the OS and different applications. These fences serve to protect memory from being overwritten by other rouge programs. This works by making each program think that it's start of memory IS the actual start of physical memory. For example. Program "foobar" may be located at memory address 0xFF44 bytes, and have 0xFF bytes allocated to it. Instead of addressing its memory in the base:offset format as 0xFF44:0xFF, it thinks that 0xFF44 is actually address 0x00 and the top of memory is 0xFF. That way, it can't write to physical addresses at 0xFF43 or anything else lower. This range of memory can be broken into fragments and scattered through memory so that if other programs have been allocated since foobar started, it's not trapped.

Bear in mind, this is only the basic gist of what virtual memory is all about. This particlar subsystem will also handle memory paging (which is part of swapping out to disk), amongst other tasks.

Before you really get determined to start hacking the kernel tomorrow, I suggest you start with something a little more meager. You need to get some experience in computer arcitecture fundamentals, then really basic OS design. Read a few books. Learn Motorola or IA32 Assembly language. Learn to write some old DOS programs (a number of DOS emulators with free, open source DOS distros are available, so some searching) where you have to allocate every byte and word by hand, and not just say "Foo *f; f=new Foo();". Next, start to learn C and figure out what malloc() is all about. Then try coding a kernel module. This is obviously not an extensive road map, but computers and their operating systems are sophisticated. You can't really (unless you're someone like Cox or Torvalds) just dive right into systems programming and know what you're doing. It may take years of experience before you start to tinker with code in the kernel and actually write something that works.

Re:virtual memory (3, Funny)

hawk (1151) | more than 12 years ago | (#2532935)

>These fences serve to protect memory from being overwritten by other
>rouge programs.


Yeah. I just *hate* it when my programs end up with makeup on them . . .


:)


hawk

Re:What is a vm? (2)

LizardKing (5245) | more than 12 years ago | (#2532929)

Your computers processor maps memory addresses used by the kernel to physical addresses in the machine. The VM handles the software side of this, as well as paging less regularily accessed memory out to the swap partition on disk. The endless debates and tinkering stem from how difficult it is to create a VM that performs brilliantly under all situations. For a good treatment of Unix internals, see "Design and Implementation of the 4.4BSD Opertaing System" or "Design of the Unix Operating System" by Bach.

This is awesome... (-1, Offtopic)

Anonymous Coward | more than 12 years ago | (#2532430)

I mean this is right up there with putting men into space or discovering cures for diseases. Now that Alan and Linus have a agreed on a VM I can see that it will usher in a whole new era in the history of humanity: the so called Age of Aquarius.

This is definately "News for Nerds" but it isn't "Stuff that matters". Maybe a Linux only site should report this. Oh wait...that's what Slashdot is.

Settlement? (2, Insightful)

utdpenguin (413984) | more than 12 years ago | (#2532442)

Maybe I am conpletely erroneous here, but I dont think so. :)

But, is this really soemthign that cna be defined as "settling." As I understand it (correct me if I'm wrong) Linus put the new VM into his kernel. Its been there ever since. And its not going away. Rather Cox is giving in the Linux, as he should, since Linus is in charge. This isnt settlement, its the natural course of development. A change is proposed, Linus oks it and impelments it. Everyone else follows suit sooner or later.

I understnad the potential horror of a kernel split, but does anyoner eally ebelieve that was going to happen? Im betting Cox would rather use a far inferior VM than allow a total split, simply because of the magnitude of suhc an action.

That is good news. (1)

Bender Unit 22 (216955) | more than 12 years ago | (#2532456)

Thas is good news. If there's one thing that I don't need it is the choice of two trees.

Now if only I could get Mandrake to work on my i2o contoller, only RedHat72 seems to work for me but it is having problems booting on the 300gb raid after install. fscking disk geometry, it always gives me problems. :-)

Re:That is good news. (0)

Anonymous Coward | more than 12 years ago | (#2532555)

Booting from your RAID array! Shame on you.

This is a lame sentence for the lameness filter.

linux on the desktop (1)

peachboy (313367) | more than 12 years ago | (#2532462)

while i don't pretend to know a lot about how to code kernels or vm's, if the new vm is better and faster than the old, i say kudos to linus and alan. this will bring linux one step closer to being ready for primetime on the desktop. little improvements such as this (although some may not see it as being as little as others) will further solidify the linux reputation as a fast, stable platform for desktop computing.

Trusted Source (meta-topic, not off-topic I hope) (5, Insightful)

MeerCat (5914) | more than 12 years ago | (#2532497)

... honestly not meant to be a troll, but does anyone else find it strange that slashdot is reporting a ZDnet story about news re:the Linux kernel development ??

Have I missed something here ? I used to work in fraud investigation and there we have a dual scale of trusting information

- how trustworthy is this source ?
- how trustworthy is this source with regards to this type of information ?

(e.g. The Queen as a news source is considered trustworthy, but if The Queen told me the local 7-11 was going to be robbed at 11:30 tonight then I'd doubt the information).

Maybe that Jesse bloke really does know what he's talking about...

T

Shock as Alan Cox installs Windows (2)

Martin S. (98249) | more than 12 years ago | (#2532522)


Shock as Alan Cox installs [new double glassed] Windows.

Phew that was close. NOT!!!

ZDNet Advertising (1)

noz (253073) | more than 12 years ago | (#2532538)

I think it's funny that so much attention is paid to your origin (i.e. location and language) in advertising engines, and the fact that it's an article about Linux is ignored. I got a random Windows advert here [zdnet.com]. Check it out.

stable vm at last? (1)

goonda (158626) | more than 12 years ago | (#2532581)

i had been using 2.4.[789] for the past month or two on my stinkpad, and noticed some horrible swappage, especially after the system had been up for several days, with terrible interactive performance. After upgrading to 2.4.13, the problems all seem to have mysteriously vanished -- so I'm glad Linus decided to take the risk with the new VM. Hopefully we can approach something like a stable kernel. sheesh.

Differences between LINUX and FreeBSD VM design? (2, Interesting)

Anonymous Coward | more than 12 years ago | (#2532583)

Can somebody explain the differences between the Andrea Arcangelis and FreeBSD VM desing ?.

I heard a lot of times that the *BSD desing is a lot better than the Linux, is this true ?.

Thanks for comments.

Re:Differences between LINUX and FreeBSD VM design (1)

Art Deco (529557) | more than 12 years ago | (#2532778)

This would be interesting for a high level discussion. One of the reasons I switched from Linux to BSD for servers in the mid 90's was because BSD's VM system was miles ahead of Linux. I know both systems have changed a lot since then. I don't know if Linux has caught up and surpassed FreeBSD or if FreeBSD has maintained its lead.

Rik van Riel on the Future of VM Work (4, Informative)

rmadmin (532701) | more than 12 years ago | (#2532733)

I ran across an archive at OSDN.com that had a video from the 2.5 Kernel Summit (March 30th and 31st 2001). On the list of videos is 'Future VM Work presented by Rik Van Riel. Its a 1 Hour 4 Minute Video clip, but after listening to it for 5 minutes I knew it was WAY too technical for me. =P Anyways, if you want to see what he said about improving VM, head over to:

http://www.osdn.com/conferences/kernel [osdn.com]

They have Real format in both 56K and 128K streams, Mpeg, and Mp3 of his speach. Looks interesting if you've got the bandwidth and the time.

My biggest problem with Linux was the old VM. (5, Informative)

TurboRoot (249163) | more than 12 years ago | (#2532844)

We run on alot of small systems, we are talking 8-16 megs of ram here and pentium 75ish processors. We tried to use linux once, but when linux runs out of memory with the old VM, it sucked HARD. I mean, I had processes being swaped out of memory compleatly that were ACTIVE!

Why do we use such small systems? Because we want them to perform under extream load when placed on larger systems. Its smart really, its easy to benchmark a few functions on a pentium 75, than a 2 ghz pentium. If your application doesn't run peppy with one usuer on a pentirum 75, it sure as hell won't support 1000 users on 2 ghz pentium.

Thats why we have used FreeBSD for all this time, in FreeBSD the VM manager is perfect, and isnt' even slated for upgrade in the near future due to the fact it works like it should. If you are using telnet on a FreeBSD machine, and _one_ applications uses a ton of resources, that one application will run slow. But your telnet will continue on fine. Try putting 12 megs of RAM in your machine, than compiling PostgreSQL while using a telnet session. You won't even notice the compile on FreeBSD, but you will with Linux.

Funny enough, this also ties into the article earlier regarding why Linux isn't used for alot of large scale databases. Databases consume HUGE amounts of RAM and the OS under it has to be peppy about it. Linux in the past has been tuned for desktop/single user performance and not what those databases need. They need TONS of resources, and quick _CONSISTANT_ access to it.

That said, I am very happy to see them getting a better VM. Because my biggest problem with FreeBSD is its crappy java support, the most recent stable JDK it supports is 1.2.2. And thats in Linux emulation mode!

So if things work out, and Linux supports java well, and doesn' crap out when it runs out of resources. We will defiently switch to Linux, and life will be good!

Incorrect memory usage (2, Interesting)

Virtex (2914) | more than 12 years ago | (#2533008)

Has anybody else noticed that, since 2.4.10, the reported memory usage appears to be wrong? I noticed in the change logs that this was supposedly fixed in 2.4.13-pre1, but I still see the problem. Running "free" shows that I'm using up 245MB of RAM on the "-/+ buffers/cache" line (I'd paste it here, except Slashdot is rejecting the post due to "lameness filter encountered. *sigh*). Now I know I'm not using 245 MB of RAM (after subtracting out the buffers and cache), and I can prove it by running a program which allocates about 350MB of ram then frees it. When I do that, my memory usage, including swap, drops to about 70-80 MB. Is anybody else seeing this?
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