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User: tuxlove

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  1. Responsiveness vs. throughput on Linux 2.2 and 2.4 VM Systems Compared · · Score: 4, Informative

    He notes in his commentary that the 2.2 kernel "felt faster" or something to that effect, while still performing much worse in actual numbers. This is probably the manifestation of the a well-known effect in the world of performance: responsiveness and throughput are often mutually exclusive.

    In other words, given fixed parameters, it's usually not the case that you can improve both responsiveness and throughput at once. If you don't change memory, CPU speed or I/O bandwidth, and your code is devoid of excess baggage which effectively reduces one of the above, it is almost a given that the two are a tradeoff. I've personally experienced this numerous times in my own performance work, and have read the research of others that corroborate it.

    Here are some really interesting fundamental examples. One company I worked at lived and died by disk performance benchmarks, in particular the Neal Nelson benchmark. This test ran multiple concurrent processes, each of which read/wrote its own file. The files were prebuilt to be as contiguous on disk as possible so that sequential I/O operations wouldn't cause disk seeks. By the nature of the test, though, seeking would happen a lot because you had N processes each reading/writing a different contiguous file. So, you lost the benefit of the contiguousness. Until, that is, we came up with a way of scheduling disk I/Os which, given a choice of many pending I/Os in a queue, favored starting I/Os which were close to where the disk head happened to be. This wasn't your father's elevator sort! The disk head would hover in one spot for extended periods, even going backwards if necessary to avoid long seeks. It was a bit more sophisticated than that, but those are the basics.

    The effect was, if a process started a series of sequential I/O operations, such as reading a file from beginning to end, no other process could get much of anything through until it was done. So what did this do to performance? Well throughput shot through the roof because disk seeks were nonexistent. The test performed beautifully, as it only measured throughput, and we consistently won the day. However, I/O latency for the processes that had to wait was extremely high, sometimes on the order of minutes.

    Needless to say, these "enhancements" were only useful for benchmarking, or perhaps for a filesystem on which the only thing running were batch processes of some kind. It would feel slow as molasses to actual human users, verging on unusable if anyone started pounding the disk. You can't wait 60 seconds for your editor to crank up a one-page file (well, okay, we didn't use MS office in those days :). On paper it was fast as hell, in practice it seemed very slow.

    One paper I read on the subject of process scheduling postulated that by increasing the max time slice of a process you could improve performance. The idea was that you would context switch less, would improve the benefits of the CPU cache, and so on. They increased the time slice to something above 5 seconds and ran some tests. Of course, the throughput improved by some nontrivial amount. Predictably, though, the system became unusable by actual human users for the same reason as in my disk test example.

    The other extreme would be absolute responsiveness, in which you spend all your time making people happy but not getting any real work done. An example of this would be "thrashing", where the kernel spends most of its time context switching and not actually running any one process for an appreciable amount of time.

    The sweet spot for the real world is somewhere inbetween, perhaps a little closer to the throughput side of the spectrum. It sounds like this may be the direction they've gone with the 2.4 kernel, though I'm sure they've done a lot of optimizing and rearchitecting to improve performance overall.

  2. Free spyware!! on GNU Carnivore With Perl Data Lookup · · Score: 2, Interesting

    While I suppose this software could be used for legitimate security purposes, much as programs like Snort which monitor your network, the potential for abuse is great. By providing network administrators with a tool for sifting through network traffic for fun tidbits like email messages and other personal communications, the bar has been raised in the battle for privacy. Tools like this will make it that much easier for your ISP or employer to spy on you unless you take great precautions like encrypting everything. Since that's not always feasible, I guess we need to accept that there's no such thing as privacy on the net.

    Of course that was always the case, but in the past it's been similar to the "school of fish" mode of defense. By schooling, fish reduce their chance of being singled out by predators. In a group of a million fish, the chance of any particular one of them getting eaten by a shark is small. One could liken this scenario to the millions of Internet users. But now, with tools like Carnivore, you can catch all of the fish at once and devour them at your leisure.

    I think I see why it's named Carnivore.

  3. Re:Can someone enlighten me? on XOSL, an alternative to Lilo and Grub · · Score: 1

    You sound like some M$ guy asking: "Why would someone install anything but Windows?"

    If Windows was GNU, had a Linux kernel, and came with a bash shell prompt and all the usual Linux utilities, I might just ask that question. However, your analogy is a poor one for obvious reasons. I think i've asked a legitimate question because it's not at all clear to me what the differences between these bootloaders are, and why I would choose one over the other.

    My final point in my previous posting, while admittedly a bit rhetorical, is that it seems like the newer bootloaders may be going a bit overboard in the feature department. I fully believe in the KISS philosophy (Keep It Simple, Stupid), and that gratuitous functionality just adds bloat to something that's supposed to be simple.

    I'm waiting for someone to add "rogue" to the bootloader so I can play games while deciding which partition to boot from. :)

  4. Can someone enlighten me? on XOSL, an alternative to Lilo and Grub · · Score: 1

    Why do we need yet another bootloader? Lilo seems to be able to boot any OS you might want to run. Grub does the same, apparently (don't know much about it yet), but gives some additional functionality for controlling SMP boots, has a graphical interface, etc. Why didn't someone just modify Lilo to do that?

    What does XOSL bring to the table that other bootloaders don't have, or couldn't be made to have with some development?

    Pretty soon our bootloaders will be OSes in themselves.

  5. This is a bunch of whining on EFF speaks out against MAPS · · Score: 1

    The EFF can go to hell on this. MAPS is awesome. It stops spam-factories and their lazy ISPs in their tracks (even more cool is ORBS, which programmatically blocks open SMTP relays).

    Do you really want to know why the EFF is doing this? Because Dan Gillmore, one of the founders, runs an open relay himself and has been nailed for it. Never mind that his open relay has been used by spammers for nefarious purposes, and that his anti-spam measures have failed - he wants the right to have a spam-friendly SMTP server.

    My right to have a spam-relay is more important than your right not to be spammed, isn't it? That's a rhetorical question, of course. *Everyone*, that is *everyone*, except spammers themselves, feel they have the right to not be spammed. You hear that argument constantly on slashdot and elsewhere, but when it's the EFF saying that a perfectly good anti-spam measure is evil, well then, by golly, it must be evil!

    The EFF needs to get its head on straight. Like so many of the causes the EFF and Mr. Gillmore take on, this one is based on a personal problem rather than a widespread injustice. That's a poor basis for taking a stance such as the one they've taken here. It detracts from the legitimacy of the EFF.

    To fill in the details a little, Mr. Gillmore has an open relay so his friends will have a known SMTP server they can use to send mail when they're travelling and are plugging into the net on different networks/ISPs. There are numerous solutions to this problem that don't involve having an open SMTP relay. I have to wonder why Mr. Gillmore doesn't utilize one of them rather than choosing to fight a silly battle. Possible solutions might include settin up a VPN for his friends with a secure SMTP server behind it, or even having them use Yahoo mail accounts. I'm sure there are also authenticating SMTP servers out there, or similar solutions.

    MAPS is one of the best tools around for fighting spam. I would hate to see it go away.

  6. ALICE is a joke on ALICE Takes Medal At AI Competition · · Score: 1

    This is not true "AI", in any of the commonly-accepted senses. And frankly, the Loebner contest is really only a challenge to make the best "artificial conversationalist" rather than "intelligence". But nits aside, after looking at the code to ALICE, it seems that we still haven't progressed too far beyond the original "Eliza method" of comparing user input to a database of keywords/phrases/fragments to decide on an appropriate response. That's really sad.

    I'm not sure we'll ever get beyond this point without a major breakthrough in programming languages and methods. Until an "AC" (artificial conversationalist) can come closer to actually analyzing sentences and grokking them, remembering threads of a conversation and using them in formulating its statements (i.e. a stateful back-and-forth conversation, like a human would do unless on drugs), and having at least a rudimentary ego or sense of existence, we'll still be in the stone age of "computer intelligence". The pie in the sky of the Turing Test is still as far away from us as the moonshot is from the Flintstones.

  7. Some consolation on Bush Administration Stops Microsoft Breakup · · Score: 1

    The DOJ's decision not to pursue the MS breakup is disheartening, but I'm not sure it's the end of the world. Whether or not that's the case depends completely on what business restrictions they will push to have slapped on MS.

    Breakup would have been the ultimate punishment for MS, but in the end what is the suit against them all about? It's about stopping their evil business practices, which properly-designed sanctions might still be able to do something about. Granted, the Bush administration is not likely to push for strong sanctions. (Okay, they're almost certainly not going to, but one can hope.) In the off chance that they do, then the real goal here has been accomplished - protecting everyone from MS predation.

  8. No, I don't trust government employees... on Big Brother To Watch Judges? · · Score: 2, Interesting

    The Electronic Frontier Foundation (EFF) believes that if we can't trust judicial employees to use computers appropriately, then we shouldn't trust them to administer our courts. -- The EFF

    While I'm not advocating that Judges be subject to surveillance, I have to say that I do *not* trust judicial employees in the slightest. The US legal system is scary. It has very little to do with actual justice or fairness. And these are *government* employees we're talking about. The same government that runs the IRS, FBI, CIA, etc., and in the case of state governments the DMV, the state police, and so on. Does the thought of these organizations instill you with confidence in the abilities of our government workers?

    I would agree that employees in the judicial branch of government (especially judges) are probably of higher caliber than, say, your average DMV worker, that doesn't change the fact that they are government employees and are therefore highly susceptible to bouts of extreme incompetence.

    I think the EFF's rhetoric here only hurts their cause.

  9. Re:Protecting the Evil on Roxio Countersues Gracenote · · Score: 2

    This is kind of strange, we're all up in arms about Roxio.

    I have to agree. To add to your comment, they're the ones buying up or destroying all the competition. For example, they bought Toast and Cequadrat, two major competitors. They sued Prassi, a smaller competitor, for using their intellectual property (i.e. patents), and extracted $2 million dollars from them, as well as the source code to their products that use "Roxio technology". And on top of it all, they make low-quality software which has the tendency to toast computers it's installed on (pun intended).

    In short, Roxio is everything slashdotters hate. Why all the love then?

  10. Not enforcible on Microsoft EULA stokes crusade · · Score: 1

    This cannot be legal. I am quite sure they have no right to dictate how you develop software just because you use their SDK. They can dictate how you use their SDK itself, but that's it.

    I am constantly nauseated by MS and their licensing agreements that make illegal pronouncements like this. They've *all* got obviously illegal stipulations of one sort or another, but nobody's got the wherewithal or drive to fight them, it seems.

    For example, the "you can't give negative reviews to our software" clause that keeps magazines from publishing bad reports about MS software.

    Another example, the clause they use for their apps which states that the software can only be run on an MS operating system, a clause intended to thwart efforts like Wine. I don't know if they still have clauses like this in their software, but they used to.

    And the list goes on. How can they continue to get away with it?

  11. Re:Nice essay! on Harm From The Hague · · Score: 1

    clear, concise, to the point, as always from RMS.

    Too bad the GPL isn't so clear. I'm still waiting for the next rewrite that removes the vagaries.

  12. Re:No works of fantasy since Tolkien are original? on Lord of the Geeks · · Score: 1

    Obviously there's none. Yes, all stories get ideas from others, and none is *totally* original, agreed. But, there is borrowing, and then there is *borrowing*!

  13. No works of fantasy since Tolkien are original? on Lord of the Geeks · · Score: 1

    I've seen a lot of people claiming that all fantasy since Tolkien is simply an (often poor) rehashing of fundamental elements of LOTR and other Tolkien works. While I think this is quite often the case (see Sword of Shanarra and other Shanarra trash, the Wheel of Time Harlequin romance series, ad nauseum), there are many examples of highly original fantasy that don't pilfer from Tolkien.

    Two wonderful examples are the "Nine Princes in Amber" series by Roger Zelazny (especially the first 5 originals, I'm not so keen on the sequels), and the "Black Company" series by Glen Cook (once again, the first 5 are best, but all are very good).

    These, along with Tolkien, are by far my favorite books of all times. They are all fantasy, but although they supposedly occupy the same genre classification, they are very different. They are all masterworks of a very different kind, and are the products of genius which you won't find in your run-of-the-mill fantasy author.

    On an aside, if you like Zelazny, read "Lord of Light." Yet another totally original SF/fantasy novel that you will never see the likes of which again.

  14. Re:This isn't a troll, and not that rare an opinio on Lord of the Geeks · · Score: 1

    Not so. See "The King of Elfland's Daughter" by Lord Dunsany. The concept of a hard, warrior elf dwelling in the forest may have started here. Even if this was not the first, it predates Tolkien's first book in the genre, and it influenced him heavily.

    Tolkien was also influenced heavily by George Macdonald, etc. However, I generally agree that the world wouldn't be the same without Tolkien's works. He fused a lot of existing fairy-tale lore (along with a huge volume of original work) into a tale the likes of which nobody had ever created to that date or since. It's simply disingenuous to say that there was nothing special or different about Tolkien's work and that someone would have filled the gap had he not been there.

  15. You're supposed to pay for listings?! on TiVo Upgrade Isn't · · Score: 2

    I don't own a Tivo, so I don't know for sure, but aren't you supposed to *pay* for the directory listings? It's no wonder the Tivo folks made that go away for non-paying customers. As for the one-touch recording going away with version 2.0 of the software, that does sound a bit draconian. Can't see why that would require a data subscription.

    I have a friend who's a project manager at Tivo, and she tells me that they make no money on the hardware itself. They depend on subscriptions to the service to make money, which probably explains why they're starting to crack down. I've got to ask her about the other issues, now that my curiosity is piqued.

  16. Re:Virus, per 18 USC 1030 on TiVo Upgrade Isn't · · Score: 1

    I still haven't seen anyone explain what the fine print in the manual says regarding their right to change the software on your box... Might have just missed it. In any case, your whole argument goes out the window if they state in the terms that come inside the Tivo packaging that they reserve the right to change the software on the box. It just might well say something to that effect.

  17. For most people, this may actually be a good thing on Napster Going Legit · · Score: 2

    Why will a monthly fee be such a bad thing? Isn't this what everyone's been whining for? A new paradigm for buying music in which you don't pay for stuff you don't like. You don't have to buy that entire Britney album any more, you can just download the one song you like.

    From what I understand, the scheme will be a flat rate of some sort, in which case you can download as much stuff as you'd like for one fee. That seems reasonable, so long as the flat fee isn't exorbitant. Even if it is a pay-per-download fee, it's still a good thing so long as it's fair.

    I mean, kripes, isn't this what everyone's been screaming for? You can download anything, on demand, for a (presumably) reasonable cost. You get only what you want. It may seem like a loss for Napster on the surface, but it really seems like a win to me because the labels are slowly agreeing to the unheard-of model of Internet music sales w/o a "secure" music format. So in a sense Napster has won.

    Assuming the selection of music on Napster is as broad as it once was when this new scheme kicks in, the only users who will stop using it are those who just want free music, or people who don't buy enough music to justify paying a monthly fee. I hope they've thought the business model through well enough to address the latter case.

    Also, rumor has it that they will discount the rate for users who make their MP3 files available for download by other Napster users. Could be a false rumor, but it would address the issue of people giving away their bandwidth to help out Napster.

  18. Above.net no longer uses MAPS RBL on Above.net Blackholes, Unblackholes Macromedia · · Score: 3

    I'm a little confused. As a customer of Above.net, I received a notice from them stating they were no longer going to use MAPS RBL. I found this a little surprising, considering that Paul Vixie was one of the founders of MAPS and is the CTO or VP of Something at Above.net.

    In light of this, I'm confused. Is Above.net using MAPS or not? This notice came a couple of weeks ago.

  19. Re:Alternatives to MAPS/RBL, please? on Above.net Blackholes, Unblackholes Macromedia · · Score: 1

    Try ORBS, the Open Relay Behavior-modification System. It is a cool service that looks for open relays on the Internet and adds them to a their database when found. This is far less political than MAPS, as it is automated and affects ANYONE who runs an open relay. It's easy to secure a mailserver appropriately, so anyone with an open relay is either ignorant, doesn't care or is simply unaware that their server is open. ORBS takes care of that one way or another.

    My problem is that certain admins of companies I converse with are too f****** lazy to fix their servers (even though it would take 5 minutes) and are listed in ORBS. SO, I can't use it. :P

    The mechanism is similar to MAPS, utilizing DNS, so if your software can be made to do hostname lookups, then you can use ORBS.

  20. Re:Doesn't Matter. on Supreme Court To Review Child Online Protection Act · · Score: 1

    Some good insights above. Obviously you're somehow close to the issue.

    However, I have to disagree with you on one of the issues. Yes, our legislators have a lot of power, but the more they exercise it in ignorant and incompetent ways, the sooner other parts of the world will gain power over the net. If they piss off enough people and it becomes hard enough to do business in the US, you will see cheap, affordable hosting outside the US. I would not be surprised to see Mexico or Canada going for lost business.

    And yes, I know, just having a server outside the US is not the answer for a US-based company, but there are TONS of non-US porn companies who would use them.

  21. What if the pr0n site is outside the US? on Supreme Court To Review Child Online Protection Act · · Score: 2

    I wonder how they intend to make ex-US porn sites comply with an adult verification scheme? This silly law wouldn't do anything at all except kill the US online porn industry. Oh, there is one thing it would do - make someone rich, probably whoever runs the verification service. Gee, I wonder if they're part of the lobby?

    How come our wonderful US legislators still don't understand that the Internet is a worldwide network they can't control?

  22. Re:I really like TLG on Lone Gunmen Get the Axe From Fox · · Score: 1

    I hate TV shows about "dumb, average people", so I can't stand Simpsons, Family Guy, etc.

    Yeah, but these are shows about "really dumb, below-average people".

  23. "IIS sucks" is news? on Microsoft Admits To Backdoor In IIS [updated] · · Score: 1

    I think it's well established that IIS is a hunk of Internet Swiss cheese. This story just reinforces that yet again. Yada Yada.

    Anyone using IIS for actual important stuff and making it publically accessible is either extremely ignorant or very stupid. You can't secure IIS, so if you use it you are simply acknowledging to the world that you don't care about the sanctity of your host system.

  24. Re:wtf on Interview with Monte Davidoff · · Score: 1

    +5? what the hell are you talking about previous life? christ this post is lame!

    I.e. a previous job. Troll.

  25. I think this is hilarious on Gracenote Sues Roxio Over Switch to Free Song Database · · Score: 1

    We all have about 5 paragraphs of text from both parties, Gracenote and Roxio, and a bunch of IANALs trying to interpret patents and the DMCA. And here we are drawing conclusions about who's evil and who's not, whose lawsuit is frivolous and whose isn't.

    It makes for entertaining reading, which I guess is what slashdot is all about. There are absolutely 0 facts, however, which makes most of this ranting completely useless short of fun reading.