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Torvalds Explains Scheduler Decision 411

Posted by kdawson
from the it's-the-guy-not-the-code dept.
Firedog writes "There's been a lot of recent debate over why Linus Torvalds chose the new CFS process scheduler written by Ingo Molnar over the SD process scheduler written by Con Kolivas, ranging from discussing the quality of the code to favoritism and outright conspiracy theories. KernelTrap is now reporting Linus Torvalds' official stance as to why he chose the code that he did. 'People who think SD was "perfect" were simply ignoring reality,' Linus is quoted as saying. He goes on to explain that he selected the Completely Fair Scheduler because it had a maintainer who has proven himself willing and able to address problems as they are discovered. In the end, the relevance to normal Linux users is twofold: one is the question as to whether or not the Linux development model is working, and the other is the question as to whether the recently released 2.6.23 kernel will deliver an improved desktop experience."
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Torvalds Explains Scheduler Decision

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  • by Anonymous Coward on Saturday July 28, 2007 @03:46PM (#20025457)
    As it seems many others don't agree to his opinions of Con, http://lkml.org/lkml/2007/7/27/426 [lkml.org]
  • by acidrain (35064) on Saturday July 28, 2007 @03:51PM (#20025491)

    Having had my fair share disagreements with customers over technical issues, it just isn't worth trying to "win." The damage to your working relationships is still there even if you are shown to be 100% right. Try and help them address their problems as much as you possibly can, while trying to compromise as little as possible of the design. It's called diplomacy, and it's the difference between being given huge amounts of responsibility, and wanting to quit. You don't even have to agree with them, you just have to make them think you care.

    Finally, it is common for programmers to try to avoid a subset of the problems in an area because it gives them the ability to write something "correct." Certainly a very satisfying experience for a programmer. However, that is exactly why it can be a bad idea to let a programmer rewrite a messy module. Very soon you can find the users of that module asking why a laundry list of things don't work anymore and an idealist developer trying to argue that they shouldn't... And it is exactly those idealists that like to rewrite working code. Not that major rewrites are bad, just that they have to be approached by someone mature enough to both expect a list of things they overlooked, and be willing to work with customers to resolve them.

  • by heinousjay (683506) on Saturday July 28, 2007 @03:57PM (#20025545) Journal
    The guy walked away. It's like quitting the Internet. Obviously if your reaction is to take your ball and go home (and I know, the ball is everybody's in this situation, but go with it) then you aren't mature enough to handle the responsibility Linus requires.
  • Re:good for you (Score:3, Insightful)

    by whoever57 (658626) on Saturday July 28, 2007 @04:00PM (#20025575) Journal

    nobody cares about the scheduler. I do care about the lack of ZFS support.
    Get over your personal issues already. I was able to improve the performance of a file server by changing the I/O scheduler from the default. I care!
  • by MBCook (132727) <foobarsoft@foobarsoft.com> on Saturday July 28, 2007 @04:04PM (#20025619) Homepage

    Number one can't be done some times. You may want Linux on the desktop, but at this point it is big on the server. It is used for a LOT of important stuff. If a scheduler makes games better but hurts general server performance, they just can't put that in without people eithe forking or switching. Now if it improved games and other desktop usage quite a bit but had a tiny effect on servers, that could be tennable. But if the effect wasn'nt tiny, they just couldn't blindly merge it.

    All that said Linus makes a good argument. If the guy wasn't addressing problems well and was just arguing "that's not my scheduler's fault" or "prove that's a big problem" etc instead of working with people, there is a very good reason not to merge the code. Ingo wrote his quick and has spent lots of time with people since he did that working with others to find and fix problem workloads. He just seems to have been much more responsible about maintaining his scheduler and it's good performace.

    There are trade-offs in evertying, and it sounds like Linus made a perfectly valid one here.

  • by realdodgeman (1113225) on Saturday July 28, 2007 @04:13PM (#20025687) Homepage
    I find Linus' comments very interesting, and very honest. He has good arguments, and to me it seems like he did the right thing. He is even open to change scheduler if someone can prove that SD does a better job than CFS, and get someone reliable to maintain it.
  • by Anonymous Coward on Saturday July 28, 2007 @04:24PM (#20025779)
    Like a guy can't be convinced of a good idea after some thought and debate?
  • by Anonymous Coward on Saturday July 28, 2007 @04:28PM (#20025811)
    It's an interesting set of emails. In addition to admitting that he actually didn't have any problem with the SD code, Linus points out that he made a gut call that Con is difficult to deal with without even looking into it because, apparently on near religious grounds, he doesn't believe in reading "specialized" mailing lists. What i find of concern is that he'd express such strong opinions about people basically without having even spent an hour or two browsing some list archives. Further, he seems perfectly aware that he may have heard just one side of the story, and yet he STILL doesn't feel he needs to look into it further or to soften his view? WTF ?

    Has Linux kernel development always been this ... arbitrary ?

    From TFA (actually form the quoted emails) after several mails where Linus has been bashing this Con Kolivas guy for not taking feedback and being argumentative, and then offers some statements about the virtues of a good maintainer some guy "Kasper Sandberg" asks him:

    "Okay, i wasn't going to ask, but i'll do it anyway, did you even read the
    threads about SD?"

    to which Linus responds:

    "I don't _ever_ go on specialty mailing lists. I don't read -mm, and I
    don't read the -fs mailing lists. I don't think they are interesting.

    And I tried to explain why: people who concentrate on one thing tend to
    become this self-selecting group that never looks at anything else, and
    then rejects outside input from people who hadn't become part of the 'mind
    meld'.

    That's what I think I saw - I saw the reactions from where external people
    were talking and cc'ing me.

    And yes, it's quite possible that I also got a very one-sided picture of
    it. I'm not disputing that.
    "

  • Re:Nerds (Score:5, Insightful)

    by Tadrith (557354) on Saturday July 28, 2007 @04:31PM (#20025837) Homepage
    That's not really fair. Slashdot pretty much covers all things science, be it computer science, or quantum physics. There are frequently articles posted which I, being in the field of computer science, do not necessarily understand or comprehend. I'm not going to tell all of the quantum physicists out there that "slashdot is not the place for them" because Slashdot IS for them. While it might have a technical slant to it, I think it's a place for anyone more interested in hearing news of advancements in various scientific fields, rather than what prison Paris Hilton is going to next.

    For that matter, even when I don't understand what an article is talking about, I am still usually more than interested to read about it.
  • by Anonymous Coward on Saturday July 28, 2007 @04:35PM (#20025877)
    Whatever way you want to paint it, that's exactly what he did.

    He believes that Ingo is a more reliable maintainer, so he chose Ingo's few-day old hack instead of Con's very mature and well tested scheduler.

    Personally, I think that the person who is at fault here is Ingo, because he has a "Not Invented Here / By Me" mentality, and instead of developing Con's scheduler further, he totally objected to Con's work for ages (which prevented it from getting into mainline), and then suddenly saw the light and wrote his own quick hack based on the same design.

    Ingo may be a good developer and maintainer, but he sure as hell isn't a friendly co-developer.
  • by arivanov (12034) on Saturday July 28, 2007 @04:46PM (#20025991) Homepage
    Well...

    If we look at the core linux developers every single one of them has been flamed into a crisp by Linus on the average every few years (and some of them flamed back in turn). Every single one of them has had something turned down in flames and an alternative merged as well (in some cases Linus admitting that he made the wrong choice later). And I cannot recall anyone of them behaving like such a hissy primadonna.

    Similarly, I have flamed people in a crips at work, I have been flamed back and I still work with this people 8+ years later. In some cases we have even come again to the same company and the same team to work together. It is just software, it is just a job and any code you have ever written can and would be ripped out by the project leader one day to be replaced by something else. Accepting this as a given is a sign of maturity. If you cannot do that, you are not mature enough to maintain a critical part of a software project. You should go away and play with toys in the sandpit for a while until you grow up.

    Sorry, the guy does not get a bit of my sympathy.
  • by 3seas (184403) on Saturday July 28, 2007 @04:49PM (#20026015) Journal
    ... I find a bit of hypocrisy.

    Three is right, as its Con and an email exchange between Linus and another.

    Whooo hooo..

    That settles it.... everybody is accounted for..... right??

    Its open source but with all the talk about having a maintainer of certain character as a part of the consideration of .... consideration about inclusion of code they wrote.. Uhhh did I forget to say its "Open Source"?
    Its not uncommon for pioneers to be forgotten as what comes next, takes over...
    Or does this mean that when a maintainer dies, so does what they were maintaining?

    The general message Con seemed to be expressing was more interesting as a general observation than of specific code.

    The response from Linus suggest that although Linus does not frequent specific topic lists because of inherent bias, he has his bias none the less.

    There is a general across the board bias, proprietary and open source, and it is one of exclusion of the end users.
    And it comes across as arrogance motivated by money and/or ego.

    To explain, programming is an act that includes creating functionality that is then accessible thru an easier to use interface such as a function call with arguements and expected return value. The general concept is common knowledge in coding regardless of what programming language you are using,

    However, this concept is not typically provided to the end user, but instead kept away from the user and certainly not provided to the user, when some distortion of it is provided the user, in any sort of easy common consistent manner.

    To clarify, users access programs typically via a command line or GUI. Neither of which are so conducive to allowing teh users to put things together for themselves. All the functionality if available to the user via the programs GUI or command line. But the same functionality is not available in an mode that allows user to call the functionality in the program and make use of the results outside of teh programs command line or GUI interface.

    Con mentioned the Amiga. The Amiga had all three user interfaces. The command Line, The GUI and the missing user interface an every other system today, The IPC port interface, most commonly known as the AREXX port but did not need AREXX running in order to use the port for "user putting things together for themselves".

    SO YOU DON'T LET USER PUT THINGS TOGETHER FOR THEMSELVES! WHY NOT?

    Cause you can dumb down the user and get ideas from them and sell those ideas implemented, back to them.

    But when you take away from the users, the ability to put things together for themselves, then that makes you a hypocrite when you then call them ignorant, armchair coders or any other demeaning term. As it is you who have created that self supported dependency of trying to justify your lack of inclusion of others.

    Con outright stated how he got started.

    Maybe You linus and a whole world of other coders, need to pull you head out of your asses and SERIOUSLY realize, THERE ARE OTHERS you are not considering.

    Ultimately, if people want to optimize their system for their needs, they should be able to. But there is serious prevention of that across the board.

  • by Bin Naden (910327) on Saturday July 28, 2007 @05:01PM (#20026107)
    As Linus explained, he has tough decisions to make and the fact that CFS beat out SD this time, doesn't mean it will remain that way in future releases. Con should have sucked it up and worked harder on his scheduler.
  • by Anonymous Coward on Saturday July 28, 2007 @05:08PM (#20026187)
    Linus takes his position as "benevolent dictator" too seriously. Specifically, he seems to root out strong personalities who aren't directly beneath him in the feudal order. All ego is his, all political judgment is his, all technical judgment is his. If you don't subjugate yourself to Linus and receive his personal blessing, then you aren't allowed to wield any of these things, because they all flow from him.
  • by Anonymous Coward on Saturday July 28, 2007 @05:32PM (#20026377)
    From the discussion it seems that Con Kolivas tried very hard to do what you're describing and ultimately had to tell off a single guy who kept harassing him after receiving much, much reasonable treatment and accomodation. Businesses do this all the time.

    It also seems that Linus was tricked into torpedoing Con by people who gave him a very warped account of Con's actions. Either Linus got played and turned into a political tool of some anti-ck people, or he's making it appear that way to seem like an innocent victim. Linus evidently screwed up big-time here... but that should be expected from time to time.
  • by forgoil (104808) on Saturday July 28, 2007 @05:33PM (#20026387) Homepage
    Start profiling the damn thing! Write performance tests, good ones, write really evil stress tests, stress the crap out of it, and then you will know what is *wrong*. Might not be the kernel at all, in fact, I think that a lot will be because of applications (always a huge source for problems), the UI/Graphics subsystem (again, huge source for trouble, X11, drivers, UI toolkits, they all tend to be far from perfect) and such.

    But pissing and moaning won't do you any good. At least Con did try to write stuff, but not being a professional software engineer hurt his efforts I'm assuming. The guy would probably make a good technical manager though. It is a shame he felt he had to quit, it would have been much better if he could have gotten a few other kernel hackers on with him to go on. I think he ended up with a lot of users backing him, but no coders :(

    Not that I am a Linux person, but I always find it sad to see people who are really into something quitting for bad reasons (bad in the sense that the shouldn't have to, not that he did something unwise).
  • Re:Why not both? (Score:3, Insightful)

    by r_jensen11 (598210) on Saturday July 28, 2007 @05:34PM (#20026395)
    I'm voting for keeping it selectable when compiling the kernel.

    You talk about a program favoring one scheduler over another or using generic calls. There are tons of programs out there already, without this new scheduler in mind, and they are running better than with the old scheduler. After this scheduler becomes common-placed, I'm sure the then-new programs will have some examples of running better with the old scheduler.

    Keep both schedulers in the kernel, but only allow the users or the distributions to build one into the running kernels. This way it's the best of both worlds.
  • by TheRaven64 (641858) on Saturday July 28, 2007 @05:48PM (#20026523) Journal
    There's nothing wrong with having multiple schedulers in the tree. FreeBSD has two. 4BSD is stable, provides excellent throughput and is ideal for server workloads. ULE is newer, less tested (only been in use for about three years), and much better for latency-sensitive workloads, such as desktops. Both are actively developed. Users can pick the one they want as a compile-time option (4BSD is the default, since it has a decade more testing, and FreeBSD users tend to prefer 'stable' to 'shiny').

    The situation for Linux is even simpler, since hardly anyone actually uses the stock kernel. Most Linux users use a kernel supplied by a distribution, which is compiled with a specific set of options and typically a few hundred patches. If one scheduler is good for desktops, and one good for servers, then merge them both and let desktop-focussed distros pick one and server-focussed ones pick the other.

  • by Professor_UNIX (867045) on Saturday July 28, 2007 @05:58PM (#20026593)
    If you don't like the way he's running the project you're free to fork the kernel and assemble your own team. Sound like too much work for too little in return? Welcome to his world.
  • by Anonymous Coward on Saturday July 28, 2007 @06:18PM (#20026739)
    This is a nonsense idea of a way of life. Life's too short to carry on with a task that is thankless, has lost its enjoyment, and has taken a toll on your health and relationships. Have you even read Con's side?

    There is no taking of balls home, just a clash with the monster egos of the Linux kernel. Don't question Con's maturity because he's made a decision to change his life. This in itself makes you sound seventeen and with no experience of life. There may be two sides to this story, so I won't make a judgement yet, but Linus has hardly shown himself to be broad and balanced in the past, has he?

    The uncontrollable ego and senseless flaming that is associated with programming is nothing to be proud of and a block to new blood and new personality types (like Con's) getting involved, leaving us with this self-perpetuating industry of arrogant computer scientists attracting nothing but other arrogant computer scientists who are unmoved in by, and ignorant of, what their users want. Fine if you live in a bubble, but doomed by natural selection.
  • Re:Nerds (Score:5, Insightful)

    by tloh (451585) on Saturday July 28, 2007 @06:48PM (#20026959)
    Furtunately, you're offering just an uninformed (and trivial at that) opinion. Unfortunately, you opinion seems to resonate with a large segment of similarly narrow-minded slashdot users. It is particularly tragic when folks here gravitate toward one steep world view without any desire to explore anything else outside of their comfort zone. It is a good thing that vocal narrow-minded elitist views (irritating as they are) are easy to ignore. The fact that diverse stories make it onto slashdot for all to discuss speaks volumes about that kind of site Slashdot actually is. We choose which stories we wish to participate in. The reality is that no one person (or even groups of persons) gets to define what slashdot is or isn't. Instead of helping to insulting others for not knowing much about the inner workings of the kernel, wouldn't it be more instructive to educate them on a subject which you (presumably) are more knowledgeble of? Instead of pushing your own agenda on a public community, why not take the time to look around and listen to what others may have to offer and then make the effort to make *your* contribution to other who need it? Please understand, I am not trying to attack you personally. I'm sure you're a decent upstanding guy. But the perspective of the opinion you've just expressed comes from a direction that hails from the most unsavory part of this great community, one that insults inteligent people and gives us all a bad name.
  • by Vellmont (569020) on Saturday July 28, 2007 @07:32PM (#20027271)

    Having lurked on http://www.lkml.org/ [lkml.org] for several years, I find Linus to be rather rude.

    I think you mistake brutal honesty for rudeness. The post referenced is a bit harsh, but it's honest and to the point about how he feels. Politeness can often get in the way of expressing a point. That's not to say politeness isn't a valueable skill at all, it certainly is for a salesman or customer service person. I can be for many jobs, but being to the point is often more valueable in science and technology.

    I don't read lkml very often, but from what I've read I think Linus is just strong willed about the things he has strong feelings for. Politeness has the potential to spill over into letting "bad" code into the kernel. Politeness can also hide peoples true intentions, which for anyone that just wants to understand the value system used to judge an idea can be maddening.

    Imagine a scenario where there's a pushy person who overwhelms a person with a polite instinct. The polite person might just eventually give in instead of stating harsh realities defending what they believe to be the best idea. The pushy person might never learn why the polite person won't just accept what they think is right. It's not the best option for an honest discussion.

    Anyway, I think you need to look at the situation as a discussion about what the best code is, and who does the best job at producing that code. Falling in love with your code (or anything you produce really) is a bad idea. It seems the kernel maintainer of the SD scheduler did just that, and Linus is only pointing that out.
  • by Frankie70 (803801) on Saturday July 28, 2007 @07:45PM (#20027371)

    Con should have sucked it up and worked harder on his scheduler.

    And what would have been his reward for that.
  • by MrNaz (730548) on Saturday July 28, 2007 @08:10PM (#20027541) Homepage
    Why are people so willing to say "deal with Linux and its failures or make use of one of your many alternatives" in response to genuine missteps by the Linux Dev community, yet people carry on about MS in some masochistic self-inflicted orgy of bitchiness.

    If you're so hell bent on bringing MS's flaws into the bright light of community awareness, then stand up, be a fucking man, and apply that same attitude to Linux, or one day you'll wake up and Linux will be just as big a bug ridden piece of shit thanks to you stripping away the very system of honest objective peer review that has kept both the codebase and community bug free.
  • Re:Why not both? (Score:3, Insightful)

    by bersl2 (689221) on Saturday July 28, 2007 @08:22PM (#20027609) Journal
    I really don't understand why Linus didn't take this approach*. He could have merged SD with the stipulation that he'd rip it out if he ever wanted to. I'm sure this would have kept Con around, instead of chasing off an important resource to the kernel's development.

    Of course, I get the distinct impression that Linus' impression of Con is not nearly as favorable as others'. I wonder why that is...

    * I mean, I know why he didn't, but...
  • by Tran (721196) on Saturday July 28, 2007 @08:45PM (#20027743)
    over MS ones any day.
    Sounds to me either scheduler will do the job just fine.
    The decision between two good alternatives is always a difficult decision - someone, no matter how good the ideas, will feel slighted.
  • by MrCopilot (871878) on Saturday July 28, 2007 @10:11PM (#20028339) Homepage Journal
    I say this because, As a practical matter Linus is right again.

    One only has to look at the reaction of a programmer who quits because his pet project didn't get into the mainline kernel. He obviously was not the best choice for a long term maintainer.

    Arguements over which code was superior are irrelevant at this point. The decision was made and will be made again when next revisited, after extensive testing and reporting. Right now the independent reports recieved by Linus were that they were pretty much equal. That only left him with the decision of who would be the better maintainer. He is the guy who gets to choose and I think he chose wisely. No offense to Con. I wish him all the best and hope he reconsiders as he matures.

    I play games under Linux and I appreciate Con's efforts, but I understand that it is not the OS only focus. He didn't, Ingo does.

    All Hail the Benovolent Dictator Linus. May his pragmatic glory shine upon thee.

  • by paleshadows (1127459) on Saturday July 28, 2007 @10:19PM (#20028405)

    A few months before Ingo wrote the O(1) scheduler, he flamed anyone who dared to suggest that an O(n) scheduler is a bad idea. He was *very* aggressive about it, going on and on about why O(n) is best and how O(1) would be worthless. Using Linus's words (about Con), Ingo "ended up arguing against people who reported problems [scheduler linearity], rather than trying to work with them". It therefore seems a bit strange that Linus uses this statement to describe Con, arguing this is why he favors Ingo...

    Importantly, Ingo was dead wrong back then (indeed, this is why months after, Ingo came up with the O(1), announcing it as if it was his idea and as if nothing ever happened, not *ever* saying something like "I was wrong, sorry for the flames").

    In contrast, Con was right in refusing to pollute the design of SD with Ingo's unfairness discipline. (This is what Linus referred to when he made the "arguing against" statement.) And what do you know? A few years after, Ingo comes up with a "Completely Fair Scheduler"...

    I'm in scheduling research for many years. I followed the long Linux scheduling saga, which actually started way before Con was in business. Please believe when I tell you: Linus comments about Con are ludicrous, and petty. This is not Linus's finest hour.

    Note however that this does not mean that Linus made the wrong decision: Even though SD is somewhat better than CFS, Ingo is orders of magnitude a better programmer than Con, orders of magnitude more knowledgeable, he gets paid to do the work, has gotten along with Linus for years, and will eventually make CFS as good as SD and even better. This is the real reason for Linus's decision. (Or at least, it should be.)

    But the stuff Linus said about Con... well, that's just Linus being small.

  • by Anonymous Coward on Saturday July 28, 2007 @10:19PM (#20028407)
    Don't worry, there are enough non-knowledgeable people here to mod you down. I must admit that this debate really boils down to Linus and Ingo taking a long time to reach Con's conclusions, and then not being as gracious about it as they could be. Con, of course, was insulted by this (who wouldn't be?) and all the while we had two major camps of Linux users: the pro-CK one (holy crap! My system works with this patchset!) and the anti-CK one (damn! My server doesn't need this, wtf?).

    In the end this just demonstrates that having egotistical bastards running the show isn't always going to yield the best results. Linus and Ingo do fantastic work, and they do sub-par work. But when someone points the sub-par stuff out, head for the hills! They will always have a legion of fans defending them, more than willing to dumb-down the real issue in favor of pretending their infallible leaders are never wrong.
  • by Anonymous Coward on Saturday July 28, 2007 @10:22PM (#20028431)
    It's not that they are rude, its just that they don't care so much about being polite.

    Um, no. It's that their definition of polite is not the same as yours.
  • by jurgen (14843) on Saturday July 28, 2007 @10:36PM (#20028525)
    This whole situation reminds me a lot of devfs. The developer of devfs (Richard Gooch) was maybe a bit of an outsider with good ideas and strong opinions that sometimes clashed with those of kernel developers that were more insiders or closer to Linus. The story is a little different in that devfs had actually made it into the mainline kernel, but then later was replaced by udev (the first draft of which was by Greg KH in a day or so... again very much like Ingo's whipping up the first draft of CFS).

    Then as now with CK, eventually Richard stopped doing linux kernel work altogether. I thought it was a sad loss of a talented kernel hacker, and I had been a devfs user, but I must say that in retrospect I do think udev is a better solution. It is simpler, has less impact on the rest of the kernel, but has proven itself to solve all the problems devfs tried to solve that actually mattered.

    What's the moral of the story? That both sides are right... on the one hand, there's something sad here, because at least several times in linux history an outsider had to fight for innovation and in the end was pushed away even as his innovation was grudgingly adopted by reinventing it. On the other hand the actual results do seem to indicate that linux is NOT resistant to change, and maybe that the better, more maintainable solution tends to win out.

    There's also another thing to keep in mind... it is a pattern in this history of technology that the first attempt to solve a problem is rarely the one that becomes dominant. Both Con Kolivas and Richard Gooch should be recognized for the innovators that they are... and if they were wise they should also not begrudge the fact that it wasn't their exact solution which eventually got adopted by the mainstream. I know this is difficult... they both put a /lot/ of energy into their work. But that energy was not lost to the rest of us, as without the experience of their groundbreaking we would not have gotten the solutions we eventually did. Even if Greg KH's udev and Ingo's CFS share no appreciable amount of code or algorithms with devfs and SD, if they are honorable, I'm sure they would admit that they could not have so quickly whipped up their solutions without the example and inspiration of RG and CK's work.

    Finally, I would like to add that although the way I see all this, it has little if anything to do with Linus's personality, nevertheless I think Linus could have handled these cases better. /Maybe/ instead of losing them in the long run we could have gotten some more innovation from talented developers like RG and CK. The problem, I think, wasn't the decision adopt CFS instead of SD. Rather, regardless of whether or not is true, the problem is Linus's public judgement that CK is not a "responsive maintainer". I didn't follow the CK or the lkml lists in that time frame enough to know if he is right... but a really good leader would not have made such a judgement public even if hed believed it, and instead would have worked to find a way to keep such talented persons contributing.

  • by QuantumG (50515) <qg@biodome.org> on Saturday July 28, 2007 @11:06PM (#20028743) Homepage Journal

    Con finished what he started. He produced a bunch of code and people can choose to take it or leave it.
    hehe, that's not the way the kernel works. If you don't wanna stick around and maintain it, they don't want it.
  • by Anonymous Coward on Saturday July 28, 2007 @11:08PM (#20028767)
    I love it when web denizens who know only how to code 'html' love to bring in their views of someones motives.

    Con didnt take his ball and go home, he finished what he started, did a damn fine job and is now moving to something else in his life which is going to be hard for computer geeks to understand.
    The man does not live and breath technology, its just a hobby. By profession he is a doctor; a specialist in anaesthesia.

    I got to know him when he was working on a benchmarking tool called Contest and truly is a renaissance man. I appreciate Stallman's knowledge of french, spanish, and of literature but he is a computer geek first and foremost.
    Con will probably take up some other intellectual challenge like he did coding and be good at it too. He doesnt NEED to do just this and many cannnot grasp that.

    Life is really too short to deal with egos when you are talented and have full of interests.

    Doctor Colivas will do just fine.
  • by IGnatius T Foobar (4328) on Saturday July 28, 2007 @11:45PM (#20028975) Homepage Journal
    And so it becomes obvious what has happened here. There were two schedulers competing for inclusion in the mainline Linus kernel. Linus evaluated both and selected one. Having lost this race, Con declared Linux a failure and stormed off in a huff.

    In other words: nothing to see here, move along, the increase in desktop Linux adoption will continue its slow but steady pace.
  • by SEE (7681) on Sunday July 29, 2007 @02:31AM (#20029853) Homepage
    Somebody directing a large effort does not have the ability to fully investigate every subsidiary dispute fairly without the effort grinding to a halt. Shorthand criteria are a necessity, as are rules of thumb as to what sources to bother investigating. This will inevitably lead to a number of less-than-optimum technical decisions along the way, but the results will be markedly superior to those where the manager stops everything to thoroughly investigate every aspect of every decision.

    Con Kolivas's reaction to "losing" was not to continue to maintain SD and try to get it in later, or to try to improve CFS, but to quit kernel-hacking entirely. Which means he is not of a temperament that can accept that large projects will have arbitrary decisions that go against him, which means he would be a bad choice for the maintainer of a major kernel system. His actions in retrospect justify Torvalds's judgment that he couldn't trust him as a maintainer. Kolivas proved Torvalds correct on the management question, even if Torvalds is wrong on the technical one.
  • by Hal_Porter (817932) on Sunday July 29, 2007 @02:43AM (#20029899)
    He said Con wasn't following up on bug reports wheras Ingo did. In commercial terms he sacked Con and moved hi responsibilities to Ingo who he trusts.

    And he was right to do so - if people don't want to support their code it's useless no matter how elegant it is.
  • by Just Some Guy (3352) <kirk+slashdot@strauser.com> on Sunday July 29, 2007 @03:26AM (#20030085) Homepage Journal

    I think you mistake brutal honesty for rudeness. [...] Imagine a scenario where there's a pushy person who overwhelms a person with a polite instinct.

    I think you mistake politeness for submissiveness. For example:

    • Rude: This code sucks.
    • Blunt: I don't like this code.
    • Submissive: Well, I could see why you like it, but I'm not sure...
    • Polite: That's an interesting idea, but doesn't quite fit with the approach we're taking. Thank you for your input, though.

    You can be polite and respectful without being a pushover. This is also commonly referred to as "tact".

  • by miffo.swe (547642) <daniel.hedblom@ g m a il.com> on Sunday July 29, 2007 @03:41AM (#20030157) Homepage Journal
    It would be perfectly possible to have ten different schedulers and just choose at compile time. The question is, is it really worth it? The performance benefits are pretty small compared to if you have better optimized code in the games or better drivers for the graphics card. A better scheduler doesnt solve buggy drivers, bad coding or bad ports. If i understand Linux correctly he is more than fine with people using whatever sheduler they want in their own trees. Hes just not that hot for maintaning more than one in the vanilla tree because its not just worth it. Again, there are much bigger improvements to get in other places that people tend to completely forget.
  • by SerpentMage (13390) <[ChristianHGross] [at] [yahoo.ca]> on Sunday July 29, 2007 @11:59AM (#20032379)
    >Even though SD is somewhat better than CFS

    Ah ok a solution is better... We use that solution, right? Because after all is that not what Open Source is all about? (http://en.wikipedia.org/wiki/Meritocracy)

    Meritocracy is a system of government or other organization based on demonstrated ability (merit) and talent rather than by wealth (plutocracy), family connections (nepotism), class privilege, cronyism, popularity (as in democracy) or other historical determinants of social position and political power.

    >Ingo is orders of magnitude a better programmer than Con, orders of magnitude more knowledgeable, he gets paid to do the work, has gotten along with Linus for years, and will eventually make CFS as good as SD and even better.

    Ok so demonstrated was a scheduler that was better, but chosen was somebody who is perceived as being more knowledgeable, and gets along with Linus and EVENTUALLY will make CFS as good or better... And until EVENTUALLY hits I should wait around and suffer the problems? And how is this different from say Microsoft who refuses to fix bugs?

    Let's call this what it is! Corporatism at the open source level with Linus's nepotism!
  • by SerpentMage (13390) <[ChristianHGross] [at] [yahoo.ca]> on Sunday July 29, 2007 @12:27PM (#20032581)
    I would add:

        * Constructive: I looked at your code. Here is what is good. And here are the reasons why I am apprehensive about it. The problem that I have is that if I included the code there would be some serious ramifications namely XYZ.

    Here is what most people cannot do. They cannot be constructive because using the arguments they proposed in the constructive it would imply that they would have to change their opinion. Thus people resort to "This code sucks."

    Having written code and looked at code it is hard to have to change your opinion. We all too often fall into a trap, "this is how I did it and thus this is how everyone will do it." I suspect Linus feel into this trap because Con annoyed him personally....
  • Re:Nerds (Score:3, Insightful)

    by HeroreV (869368) on Sunday July 29, 2007 @12:29PM (#20032587) Homepage
    I'm only 19, and I've never contributed a single patch to any software project, but even I know exactly what this is about. The worry here is that the Linux kernel developers are acting like snobby elitists, and that they care more about patting each other on the back than they care about improving the kernel. They're rather shit up the kernel than listen to someone who isn't part of their inner circle. It's pretty major stuff.
  • by arivanov (12034) on Sunday July 29, 2007 @01:03PM (#20032805) Homepage
    I recall him admitting being wrong after coming on the side of Al Viro in some of the legendary Viro vs devfs and similar flamewars. As far as links, I need to remember the actual case to search for it, but I clearly remember him admitting being wrong on more than one occasion and apologising.

    Sorry for not being able to be more exact, I have stopped following LKM around Y2K and the last time I have had any brush up with lk-?? lists was when reporting the fundamental bind/connect/send vs bind/sendto cockup in ipv4/udp.c 3-4 years ago.

    Which by the way reminds me that Linus has one more point here. Selfselecting lists on one special subject suck. Based on trying to report the aforementioned ipv4/udp.c bogousity to linux-net I would absolutely agree with him here. It all went /dev/null as some "nobody" from outside the special selected club was reporting something not worthy of the divine attention of the deities. I did not get flamed "ab persona", I just got ignored. That hardly ever happens when posting questions or bug reports on lkm. You may get flamed, but someone generally looks at it.
  • by microbee (682094) on Sunday July 29, 2007 @04:06PM (#20034201)
    Con HAS sucked it up for many years - he has maintained his scheduler work out of mainline tree for a very long time. The fact is that to merge any work that touches Ingo's code, you need Ingo's bless, and Ingo simply wasn't interested or convinced that his scheduler was worse by design, and as such he refused to replace his code with Con's and always wanted to "improve the existing code".

    Then one day SD appears and Ingo suddently announced his version of a fair scheduler, and after so many years of hard work Con simply found out that it was impossible to get his work merged or acknowledged respectively. He was pretty much bypassed by the Linus - Ingo DirectMerge feature.

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