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Kernel 2.4.17 Out

ThatComputerGuy writes "Linux kernel 2.4.17 is final, with a lot of fixes/updates. Check out the huge changelog. If you're on a desktop machine, you should try using RML's preempt patch, it definitely helps response times."

75 of 350 comments (clear)

  1. Instability with the preempt patch? by Dimensio · · Score: 3, Informative

    I used the preempt patch back when 2.4.14 was released and I kept getting consistent kernel panics. Mind you, I'd also applied an -ac patch, so I can't say for certain that preemption was the cause, but it was troubling and the panics went away once I disabled preemption.

    1. Re:Instability with the preempt patch? by KnightStalker · · Score: 5, Informative

      I had similar problems with 2.4.14 and the kernel preemption patch, but I'm running it against 2.4.16 right now with spectacular results. I can play a DVD full screen when the system load (i/o bound) is greater than 3 on my single-Athlon 900. No skips, pops, jumps, anything. Smooth as silk.

      --
      * And remember, it's spelled N-e-t-s-c-a-p-e, but it's pronounced "Mozilla."
    2. Re:Instability with the preempt patch? by Spoing · · Score: 5, Informative
      Make sure that any kernel modules you load are SMP-safe. While the preempt patch does not magically make a uni-processor system into a multi-processor, it does create an environment where modules that aren't SMP-safe tend to fail or act unusually.

      Rule of thumb: If it's in the base kernel sources, you're OK. If it's a patch to the kernel sources, be careful but not overly concerned. If it's a pre-compiled binary (even if only in part), be very cautious. Remember: Google is your friend.

      Example: The Alcatel external USB DSL modem, for example, has a binary part that isn't fully SMP-safe. Because of that, it can't be used with the preempt patch even on a system with a single main CPU.

      --
      A firewall can not protect you from yourself. Turn off what you do not need. Do not use the firewall to do your work.
    3. Re:Instability with the preempt patch? by Darren+Winsper · · Score: 3, Informative

      May I recommend Benoit's Alcatel Speedtouch driver at http://benoit.papillault.free.fr/speedtouch/index. en.php3 ? It's a user mode driver, but it does need the official drivers for the modem bios object which it uploads to the modem.

      There are many reports that these are far more reliable than the official drivers and since it's entirely usermode it doesn't suffer from the SMP-safeness issues the official drivers have.

    4. Re:Instability with the preempt patch? by KnightStalker · · Score: 2

      I'm using Xine to play, with the d4d and dvdnav plugins. Menus don't always work correctly, but I usually can play the movie decently, with subtitles and alternate soundtracks. I also have a Matrox G400 and XFree86 4.1.0.

      It turns out the preemption patch didn't do much. I rebooted into a kernel without the preemption patch and I could play movies with the same reliability as with the patch. When I played through the Xshm driver (no acceleration) I got perhaps half a frame per second as opposed to one frame per second with the preemption driver enabled.

      The tests I was doing to load the system were:

      while (true); do tar -czv . > /dev/null; done (two of these on two different partitions)
      gzip < /dev/urandom > /dev/null
      cat /dev/urandom > /dev/null

      top reported the load as being around 4.0 with 60% user and 40% system.

      --
      * And remember, it's spelled N-e-t-s-c-a-p-e, but it's pronounced "Mozilla."
    5. Re:Instability with the preempt patch? by Spoing · · Score: 2

      You're right. Thanks for the correction!

      --
      A firewall can not protect you from yourself. Turn off what you do not need. Do not use the firewall to do your work.
  2. Kernel Tree by CaffeineAddict2001 · · Score: 2, Funny

    Ive got dibs on putting the star on top

  3. Wait for Final Preempt patch by pbur · · Score: 3, Informative

    You will want to wait until RML releases the finale preempt patch. It will just be the kernel version (2.4.17) without the rc on the end. His patches are very version specific.

    Pbur

    1. Re:Wait for Final Preempt patch by signe · · Score: 5, Informative

      Actually, there is a final 2.4.17 patch, but it's not on the page linked to. Go to
      http://www.kernel.org/pub/linux/kernel/people/rm l/ preempt-kernel/v2.4/ and grab it from there (or use a mirror).

      -Todd

      --
      "The details of my life are quite inconsequential..."
    2. Re:Wait for Final Preempt patch by devphil · · Score: 2


      Uhhhhh... on the page linked to in the /. article, there is no "rc" on the end. The link there for "2.4.17-1" goes to the same place (kernel.org) as your link.

      --
      You cannot apply a technological solution to a sociological problem. (Edwards' Law)
    3. Re:Wait for Final Preempt patch by pbur · · Score: 3, Informative

      You're right, he seemed to be updating the page when I posted because at the time an "rc" link existed but didn't go anywhere. RML is good like that. :)

  4. Changelog...? by Hiro+Antagonist · · Score: 3, Funny

    I haven't looked at the changelog yet, but I'm sure that there's a line reading something like

    "This time we /promise/ not to corrupt filesystems when you 'umount /mnt/tmp/lifes_work'."

    All the same, many kudos to the kernel guys for giving me something new to play with for the holiday!

    --

    --
    I Hit the Karma Cap, and All I Got Was This Lousy .sig.
  5. It appears to actually be fixes by Anthony+Boyd · · Score: 5, Interesting

    It looks like we're actually seeing 99% bug fixes this time around, rather than new features being added. Yay for having a 2.5 branch, it seems to be getting the experimental code now. This may be the first 2.4 kernel I compile for my system (I'm not saying I'm still stuck in 2.2, just that I've kept the default 2.4 kernels from my Mandrake and SuSE installs). I also see a couple ext3 fixes, which means I'm pretty comfortable having this replace the patched-to-use-ext3 2.4.10 kernel in my SuSE 7.3 box.

    1. Re:It appears to actually be fixes by ansible · · Score: 2

      Well, it's gonna be a while before I try 2.4.anything on a production machine.

      On the one hand, I'm glad to be seeing a lot of bugfixes in the changelog. On the other hand, I'm worried about seeing lots of bugs in the changelog, because I wonder how many more serious ones are lurking in the codebase.

      With 2.2.whatever, the bugfixes there have been recently have mostly been related to specific drivers, which I usually don't care about (unless I'm using that driver). But with 2.4.x I'm still seeing lots of fixes in the main kernel code, because so much fundamental structure has changed since 2.2.

      I guess we'll have to see. Maybe if some decent RAID card support starts showing up in OpenBSD, I'll think about switching my servers to that.

    2. Re:It appears to actually be fixes by josepha48 · · Score: 2
      2.4.10, 2.4.13, 2.4.16 have all been fairly stable on my desktop workstation.

      The fact that 2.4.17 was ALL bug fixes is a good sign. It means that they are fixing the issues that they know about, like parport IEEE1394 seems to work better.

      I see no reason not to use 2.4 at this point on a produciton machine. It is not until people do start doing so that we are going to find out all the kernel issues. I'd recommend trying this release if no other.

      --

      Only 'flamers' flame!

  6. VIA KT133 chipset? by blogan · · Score: 3, Interesting

    Does it work with the KT133a Chipset and Athlons? I looked and google and there were reports of the problem, but no report of a fix anywhere that I could find.

    1. Re:VIA KT133 chipset? by MikeO · · Score: 5, Informative

      A bios upgrade fixed the problem for me. Look for an update on your motherboard vendor's website.

    2. Re:VIA KT133 chipset? by KidSock · · Score: 2, Informative

      Does it work with the KT133a Chipset and Athlons?

      This was a long standing motherboard/BIOS issue. I think VIA actually found and acknowledged that some register was getting scrambled inadvertantly but I could be thinking of another peice of hardware. It's so hard to find these messages in the lkml archives even after only a few days. At any rate, I have this board. At one time I had problems but it was difficult for me to tell if it was the VIA board or the infamous IBM Deskstar 30GB drive I had that was failing. So I RMA'd the drive, bought another SCSI drive and put my 2940UW on there with the latest BIOS update. I have not had any problems since and I tortured it pretty hard. Of coure all of this is off topic because I'm using Red Hats 2.4.7 but again, this is/was a hardware/BIOS issue.

    3. Re:VIA KT133 chipset? by josepha48 · · Score: 2
      how do you upgrade a bios in Linux??

      Also does anyone know if they fixed the parport problems?

      To answer your question about KT133, there is a bug on the VIA chipset that causes some people problems.

      In my case and a few others there are IDE bugs. IDE IOMEGA zip 100 and VIA686B don't go togeather to well.

      Also some people have had problems with using the ECC/ECP part of the parport. Again, in my case it was my webcam did not work. It stopped working in 2.4.13 or 14 not sure. I had a fix for it and explained on the lkml what the problem was, but not sure if that was ever acknowledged.

      Well now I have a very good testing mechanism for testing kernels like this. I have a foo.test kernel and a foo.custom kernel. The custom kernel is the current kernel and the test is, well a test kernel. Nice thing about lilo is you can have multiple kernels. I can then boot the test kernel and make sure all works on my system. I'll be doing that tonight...

      --

      Only 'flamers' flame!

    4. Re:VIA KT133 chipset? by jmv · · Score: 2

      I have a board (ASUS A7V133) with a KT133A+T-Bird 1.33 and haven't experienced problems with any kernel I tried so far (2.4.5, 2.4.7, 2.4.8, 2.4.10 and 1.4.16). The only problem I've heard (never experienced it) with my bord was actually the VIA (866B?) southbridge.

    5. Re:VIA KT133 chipset? by josepha48 · · Score: 2
      Thanks, I do have dos disks still. I was hoping I would not have to do that again though,but I was able to upgrade my BIOS. It had fixes for several issues.

      Also it seems that between my biios update and 2.4.17 the parport issues has gone away. I think it was that they finally fixed the IEEE1394_ops.c code. Yes there were changes in this file that now makes my web cam work again ;-)

      --

      Only 'flamers' flame!

    6. Re:VIA KT133 chipset? by Karpe · · Score: 2

      The fix was included somewhere before 2.4.16. It disables a single bit in a undocumented PCI register, fixing most problems.

  7. Re:Wow by sam@caveman.org · · Score: 3, Insightful

    you don't HAVE to upgrade your linux box, either. but at least you have the OPTION of upgrading for FREE, instead of paying year after year if you want to upgrade.

    as you said, you are happy with win98, more power to you. but many people are not happy with windows and have to shell out big bucks every couple years to upgrade.

    yeah, i know, the post was flamebait. but hey, i'm a sucker for anything this obvious.

    -sam

    --
    burn the computers. go back to the abacus.
  8. New Maintainer by krackbebe · · Score: 4, Insightful

    Looks like the new kernel maintainer is really working out. I enjoy seeing these kind of detailed changelogs, to determine whether there is anything critical enough to upgrade my system.

    Seems like Alan and Linux lately haven't been all that hot about doing the drudge detail work. This arrangement seems to be the best solution for everyone.

    1. Re:New Maintainer by krmt · · Score: 4, Insightful

      Yeah, and after all the flack everyone gave him here for being terse with his interview, it's great to see his changelog speaking for him instead. Much kudos.

      --

      "I may not have morals, but I have standards."

  9. Re:I haven't finished downloading the last release by Ranger+Rick · · Score: 2, Informative

    get the patch

    --

    WWJD? JWRTFM!!!

  10. patch mirror by noodlez84 · · Score: 3, Informative

    I have mirrored the patch and signature:

    patch-2.4.17.bz2 (388KB): http://home.earthlink.net/~noodlez84/patch-2.4.17. bz2
    patch-2.4.17.bz2.sign (1KB): http://home.earthlink.net/~noodlez84/patch-2.4.17. bz2.sign

    1. Re:patch mirror by hpa · · Score: 4, Insightful

      If so, he would have to possess the kernel.org secret keys. If he does, we have some really nasty security problems that we didn't know about :-/

      This isn't just an md5sum, it's a gpg signature. You can verify it as long as you have the public key, which is widely available.

  11. Preempt Patch? by jasno · · Score: 2

    Has anyone actually tried this and noticed a difference? I was under the impression that a lot of people thought this was useless.

    --

    http://www.masturbateforpeace.com/
    1. Re:Preempt Patch? by itarget · · Score: 3, Informative

      The patch makes a big difference for me when using latency-sensitive software (xmms) while I'm really pummeling my system (big compile).

      xmms usually skips a bit while I'm compiling something large, but it hasn't even once after applying the preempt patch.

      I haven't noticed performance degredation from any effects on throughput, so it's all good here.

      --

      "Where shall the word be found, where will the word resound? Not here, there is not enough silence." -T.S. Eliot
    2. Re:Preempt Patch? by Anonymous Coward · · Score: 2, Informative

      It definitely makes a difference on my (400Mhz) system. I suspect, however, the faster your system, the less noticeable the effects will be, since it'll take less time inside the kernel regardless of whether the kernel can be pre-empted or not.

      That said, the patch is, architecturally, a good thing, as making it work better automatically makes SMP work better, and vice versa. I think it should go into the offical kernel in the 2.5 cycle, personally - even on servers, it often matters that clients are responded to quickly, to keep people at a website, say, rather than sending the absolute max amount of data down the line - so even if the preempt patch has a slight negative impact on total throughput, it's a win for responsiveness.

    3. Re:Preempt Patch? by Legion303 · · Score: 2
      Preempt made my system (around 2.4.9 or so) noticeably slower.

      -Legion

    4. Re:Preempt Patch? by PD · · Score: 2

      I installed it on 2.4.14 and I didn't notice a single bit of difference.

      BUT, I'm also not doing anything that can really take advantage of it. I don't play music or movies. The most I will ever do is run vi and gcc at the same time.

      So, it depends on what you do with your machine. The patch seems to work for people who want to play video on a machine with a high load.

    5. Re:Preempt Patch? by LinuxGeek8 · · Score: 2

      Good question.

      I never used the preempt patch, because I'm on a smp system, and it would make it rather unstable.

      But from what I hear, it helps with latency problems, but has a decrease on throughput.
      So I'm wondering, just increasing the latency does do exactly the same, doesn't it?
      I mean, I increased the latency on the pci bus, and my mp3's are almost never skipping anymore. Which is the same claim made by lovers of the preempt patch.
      I never use video stuff though, so I can't comment on that.

      For changing the latency, you can find a good read here:
      Latency

      --
      Well, don't worry about that. We can get you back before you leave. (Dr. Who)
  12. 2.4.x bigger than 2.2.y by valentyn · · Score: 2, Funny

    Ha! 2.2.18 on december 11, 2000. 2.4.0 in january, 2001. That means, roughly, 1.5 versions of 2.4 per month, while we have only 1 version of 2.2 in 6 months.
    Somewhere in april we'll have 2.4.21 and 2.2.21 and one month later, 2.4.22 will be out. Hooray!

    --
    my other sig is a 500 page novel
    1. Re:2.4.x bigger than 2.2.y by GigsVT · · Score: 2

      That's the way it is supposed to work. As a program matures, there will be less updates, and things to fix. I thought this was a pretty basic concept...

      --
      I've had enough abrasive sigs. Kittens are cute and fuzzy.
  13. Misguided versioning? by kurtras · · Score: 4, Interesting

    After several of the last few kernels being released with major bugs, I thought the consensus on LKML was to use -rc versions for bugfixes, and then release a 'final' without making any changes in it. Yet, when I read this changelog, I see that changes were made in the final version. A lot of people will only download a 'final' kernel, because they think that it contains only tested, stable code. That is what the -rc system was to ensure, but releasing a 'final' with changes means that a partially untested kernel is being released to the unsuspecting public. Now, I will admit that there's a very good solution that any user can implement - just don't upgrade. However, these recent quality control problems have given Linux something of a black eye in the public's mind. Therefore, it just seems common sense to not release a kernel with code that hasn't been in for at least one -pre or -rc revision. So, if I were a kernel maintainer, about to release kernel 2.4.18, and I received a 'critical' patch from a project maintainer, I'd make one last -rc release to ensure that the code gets tested before I release it. However, I'm not a kernel maintainer, so take this as you will. I don't mean it as a flame, and I think that Linus and Marcelo have done a wonderful job so far with Linux 2.4.

    1. Re:Misguided versioning? by be-fan · · Score: 2

      Basically, you have for each kernel version you have several -preX kernels. Once you get the thing stable, you rename the line to -rcX kernels. From here, you accept only bug-fixes. When the -rcX kernel gets really stable, you rename it to -final, without changing anything else.

      --
      A deep unwavering belief is a sure sign you're missing something...
  14. My favourite change: by schon · · Score: 2, Funny

    From pre1:

    - Speeling fix for rd.c

    Gotta love that sense of humor (at least I HOPE it was intentional :o)

  15. NTFS bug fixes? by Mr.+McGibby · · Score: 2, Interesting

    Any word on what the NTFS bug fixes involved? Any closer to a usable readwrite mode?

    --
    Mad Software: Rantings on Developing So
    1. Re:NTFS bug fixes? by Mr.+McGibby · · Score: 2, Informative

      Lack of solid documentation and licensing issues as I remember.

      --
      Mad Software: Rantings on Developing So
    2. Re:NTFS bug fixes? by Anonymous+DWord · · Score: 3, Insightful

      You remember right. Lack of *any* documentation, more like it. Licensing I don't think is a problem, as everything is done blind. MS changes NTFS every time they put out a new OS though, so that kind of complicates things.

      --
      "If he thinks he can hide and run from the United States and our allies, he's sorely mistaken." Bush on bin Laden
  16. AMD K7 SSE by BrookHarty · · Score: 3, Interesting

    in the changelong I noticed...
    pre5 - Enable K7 SSE (John Clemens)

    So we now have SSE for the K7 cpu? Does any programs on linux even take the extra speed of SSE/MMX/3D NOW? I have always wondered since these type of optimizations are only visible when the software application lists it, and most software is for windows.

    1. Re:AMD K7 SSE by Algorithm+wrangler · · Score: 4, Insightful

      SSE requires some extra effort on the OS on context-switch, since the SSE registeres are not normally saved/restored (they are only available on SSE-enabled CPUs). So SSE has been unusable on K7 up until now since you might have your programs screwed up by a context switch.

      --
      -._''_.-
  17. Re:Wow by alen · · Score: 2

    I guess then they will be just like Apple charging for OSX upgrades.

  18. Re:How stable is the preempt patch? by MindStalker · · Score: 2

    Well, why don't you try the source provided for you by your distro, it should have all the distro changes, in it. Then see if you can get the patch to work. If you can't, find a linux guru who can do it for you, and publish the patch, many people will love you :)

  19. loopback deadlocks by Anonymous Coward · · Score: 2, Interesting

    final:

    - Fix more loopback deadlocks (Andrea Arcangeli)

    the very first line of the changelog is scaring my ass of. this sounds like there are some / an unknown number of loopback deadlocks still lurking and nobody knows where, until it jumps out to rip your head off.

  20. Re:What is "preemtive" for ? by itarget · · Score: 3, Informative

    Having a preemptive kernel just means that the kernel will allow itself to be interrupted by other programs and give them some cpu time.

    This improves response time for your programs as now they won't get stuck waiting for the kernel to finish doing something time-consuming (like disk I/O) before they get some cpu cycles.
    In most cases this isn't a big deal, but you'd definitely notice when your mp3 player skips because it's stuck in line behind the kernel.

    --

    "Where shall the word be found, where will the word resound? Not here, there is not enough silence." -T.S. Eliot
  21. Re:What is "preemtive" for ? by agrapa · · Score: 2, Informative

    When a process starts a kernel call, it will not be context-swapped until it finishes executing the call. That is, the kernel will not change the executing process as long as it is kernel code that is in execution. There are many reasons for this. The patch makes it OK to to context swapping in the middle of kernel execution, helping all processes get an equal amount of CPU time.

  22. Re:Wow by __past__ · · Score: 2, Insightful

    In fact, *only* Linux users have to upgrade their kernel every so often.

    Users of proprietary OSes don't have a chance to, and users of about
    any other Free OS - well most other free OSes kernels just aren't
    broken every second week.

  23. Re:Preempt Patch? - have not noticed a difference by Darren+Winsper · · Score: 2, Informative

    My MP3s stopped skipping under heavy(ish) load. For example, when checking out the Mozilla tree, there is a lot of hard disk access for up to a minute. During this time, XMMS would often skip and crackle, whereas with the preempt patches this no longer occurs.

    Xine also seems to like the patches. I can often have two compiles going on in the background with a fair bit of swapping and DVD playback is still smooth. This was not the case without the preempt patches.

    In general, the preempt patches help if you use your system as a desktop/workstation, it could actually harm system performance if it's primarily a server.

  24. Re:Wow by rseuhs · · Score: 2
    Of course Windows users don't have to face the task of recompiling their kernel every so often.

    Neither have Linux users.

    Did I miss something? Did Bill Gates redefine the english language so that "be able to" and "have to" mean the same thing? Why don't Windroids understand the difference then?

  25. Re:bios flashing, not just from DOS anymore by thing12 · · Score: 2, Informative

    You should try out /dev/bios. It's a very cool little kernel module. I recently used it to flash the bios on one of my linux boxes that didn't have a floppy installed. Just cat the file out to /dev/bios and reboot. It's a beautiful thing, though obviously you probably wouldn't want to have it installed all the time :-)

  26. KT266A by green+pizza · · Score: 2

    I noticed someone else asking about VIA KT133 support, so I thought I'd inquire about the KT266A...
    We have two new office-brew systems, one mobo from Asus and one from Abit, both are based on the KT266A and neither will boot any flavor of kernel 2.4.x that we've thrown at it. I've done the normal google and usenet searches, but haven't found much other than a few "works for me" posts. Anyone have some pointers or patches?

  27. Re:I haven't finished downloading the last release by vrws · · Score: 2, Insightful

    damn, man! Why is this rated 'funny' with _every_ kernel release? Or am I the only one noticing/nagging?

  28. BZ2 vs GZ by jquirke · · Score: 4, Interesting

    Something I feel like asking as 2.4.17 (bz2) trickles down the connection at 0.2K/sec from Australia's Planetmirror...

    The kernel's are posted in both GZ and BZ2 formats. What do you guys mostly use? I can't see much point these days with having the Gzip format, I mean is there still a point to downloading it? Or even having them available in that format?

    From what I can see, removing the Gzipped versions

    *reduces network congestion
    *saves space on the mirrors
    *saves space on local storage (yeah only a couple megs)

    Of course, it requires more processing time to extract, but that seems to be no big deal these days. I'm pretty sure everyone has bzip2 installed , and those who don't can easily get it, so that can't be a problem.

    So is it really just traditional reasons it's posted in Gzipped format? Tell me if I've missed something. It would be interesting to know what everyone thinks about this.

    1. Re:BZ2 vs GZ by damiam · · Score: 2

      Tradition, some people don't have bunzip2, and BZ2 takes longer to decompress (a real issue on slower systems).

      --
      It's hard to be religious when certain people are never incinerated by bolts of lightning.
    2. Re:BZ2 vs GZ by TaliesinWI · · Score: 3, Insightful

      I'm sure I'm going to be showing my age when I say that I remember the Big Switch from .Z (Compress format) to .gz on most FTP sites. Is .bz2 really becoming that common? The only place I'm really exposed to it are the kernel sites, most other source code repositories are either just .gz or still have legacy .Z stuff lying around...

    3. Re:BZ2 vs GZ by Gregg+Alan · · Score: 2, Interesting

      I only use bz2 for the kernel. Seems to me that processing power is cheaper than bandwidth (lucky for me I have plenty of both.)

      If the extra time to decompress a bz2 over a gz is that great a factor, why would you even want to compile a kernel on that particular machine? Compile it on your fast box and just copy it over. That's what I do.

      --
      Here before all but 8486 of you.
    4. Re:BZ2 vs GZ by Ed+Avis · · Score: 2, Interesting

      If you're worried about download time, just get the patches!

      (Okay that only works if you've got the previous version - you can download a whole sequence of patches for bigger jumps, but after a while it gets bigger than the kernel itself. I'd like to see a general patch generator where you type in what version you currently have and it generates the smallest patch file just for you. Alternatively some way of using rsync would save on bandwidth.)

      --
      -- Ed Avis ed@membled.com
    5. Re:BZ2 vs GZ by bconway · · Score: 2

      You realize you can re-use your old .config, right? There's even an option to load or save old non-.config files in the various menuconfig/xconfig/whatever menus.

      --
      Interested in open source engine management for your Subaru?
  29. Re:3DNow! by TeknoHog · · Score: 2, Informative

    MPlayer makes use of MMX and 3Dnow! if they are available. Makes my K6-III+, 400 MHz, play DivX quite well :-)

    --
    Escher was the first MC and Giger invented the HR department.
  30. Re:What is "preemtive" for ? by be-fan · · Score: 4, Informative

    There are two things here. Preemptive in userspace, and preemptive in kernel space. Linux is preemptive in user space, meaning that when a process is running application code, it can be preempted. When it is running kernel code, however (ie. during a system call) the scheduler will not preempt the thread, even if a higher priority one becomes available. Essentially (on a single processor) the kernel code is cooperatively multitasked. Kernel code runs until schedule() is called to invoke the scheduler. Some kernel code paths are very long, which leads to long periods where the current process cannot be preempted, which kills latency.

    Also, to expand on the original question, there are a couple objections to the patch: It has the potential total throughput, because more locking must be used since the kernel can be preempted at any time, not just at specified points. However, in practice, the effect on throughput seems to be negligible. It also increases complexity, due to additional locking, but most of the complexity is there anyway, in the form of the SMP locks.

    --
    A deep unwavering belief is a sure sign you're missing something...
  31. can anyone compile it? by seandarcy · · Score: 2, Interesting

    I've got it. I'm trying to compile it. It fails at make bzImage compiling network.o. See the snippet.

    Anyone know how to fix it?

    ld -m elf_i386 -T /opt/kernel/linux-2.4.17/arch/i386/vmlinux.lds -e stext arch/i386/kernel/head.o arch/i386/kernel/init_tas
    k.o init/main.o init/version.o \
    --start-group \
    arch/i386/kernel/kernel.o arch/i386/mm/mm.o kernel/kernel.o mm/mm.o fs/fs.o ipc/ipc.o \
    drivers/char/char.o drivers/block/block.o drivers/misc/misc.o drivers/net/net.o drivers/media/media.o drivers/char
    /agp/agp.o drivers/ide/idedriver.o drivers/scsi/scsidrv.o drivers/cdrom/driver.o drivers/sound/sounddrivers.o drivers/pci/d
    river.o drivers/pnp/pnp.o drivers/video/video.o drivers/md/mddev.o \
    net/network.o \
    /opt/kernel/linux-2.4.17/arch/i386/lib/lib.a /opt/kernel/linux-2.4.17/lib/lib.a /opt/kernel/linux-2.4.17/arch/i386/
    lib/lib.a \
    --end-group \
    -o vmlinux
    net/network.o: In function `__rpc_schedule':
    net/network.o(.text+0x49a0d): undefined reference to `rpciod_tcp_dispatcher'
    make: *** [vmlinux] Error 1

    1. Re:can anyone compile it? by skriefal · · Score: 2, Informative

      Appears to be a known problem when compiling with RedHat's prerelease of the GCC 3.1 compiler.

      Here is some more information. In general, I recommend that you do not attempt to compile the Linux kernel using any version of GCC newer than 2.96.

  32. Another RML? by RML · · Score: 3, Funny

    "RML"? Robert M. Love stole my initials! Now I have to worry about people confusing me with someone who knows what he's doing.

    --
    Human/Ranger/Zangband
  33. 2.4 by Arjuna+Theban · · Score: 2, Interesting

    I've been using linux since the very early 2.0.* days and for the most part I keep up with every kernel released. Since I've moved to 2.4.*, I've notices an incredible slowdown on my machine, even in post-2.4.13 kernels which supposedly did something to improve performance.

    Personally I'm about ready to go back to good old fast&stable&reliable 2.2 tree. I wonder if we really need to make the kernel this sluggish for the sake of introducing new stuff in the kernel level though. I know I'm not the only one who noticed the performance drop with 2.4.*.

    --

  34. Re:What is "preemtive" for ? by UnknownSoldier · · Score: 3, Informative

    > I don't understand the difference between preemtive and the normal way (btw: which?).

    The normal (old) way is "cooperative" -- meaning you don't yield a task until you're ready.

    Pre-emptive means you can be forced to give up your task.

  35. Re:What is "preemtive" for ? by ASM · · Score: 2, Insightful

    That's not *quite* right. Linux has been pre-emptive since the beginning, but in userspace, not kernelspace. IE, system calls, driver code, and other kernel stuff couldn't be preempted, but user code could.

    Windows, on the other hand (9x, I don't know about NT) is fully cooperative, meaning that userland isn't preempted either. That, and poor memory protection, is why buggy windows programs can bring the system down, Whereas in linux, only kernel space stuff can lock up the system.

    The preempt patch, then just makes the kernel preemptable, so that Linux is fully preemptive, instead of just in userland.

    --
    Fish
  36. Re:This is fixed by Sits · · Score: 2, Informative

    This guy is right - the workaround for the problem has been about for a while. For more information on the problem take a look at the Via Hardware FAQ. The whole via problem has been known about for sometime (a search on Kernel Traffic for KT133 turned up a few references. The most recent reference was 2.4 Kernel freezes on VIA KT133.

    As mentioned in other comments, motherboard makers were encouraged to workaround this at bios level.

  37. Preempt patch and 3rd party modules by loftwyr · · Score: 2, Interesting

    I installed the patch, recompiled and both ALSA 5.12a and nvidia's kernel module were broken. I got unresolved symbols.

    It would be nice if there was some way to exempt these two from the optimization or there was a doc explaining what I would need to change

  38. Re:What's the point? by be-fan · · Score: 2

    Because they have a sane versioning system and don't try to be all 'leet and artificially keep their version numbers down! What is it about OSS developers that makes them dispise version numbers above 1.0?

    --
    A deep unwavering belief is a sure sign you're missing something...
  39. Re:What is "preemtive" for ? by be-fan · · Score: 3, Informative

    Ah! Partially right! But sorry, no dice. The only cooperative multitasking that is done in Windows 9x is with 16 bit applications, since all 16-bit apps are run in the same virtual machine. All 32-bit apps are fully preemptively (userspace multitasked. As for memory protection, that's only partially true. Application memory is indeed protected from each other. However, there is a big 1GB region of shared memory that is unprotected. Apps that use this region and asking to hose the system. Also, some bits of kernel memory are unprotected because DOS apps need access to them.

    As for NT, it is a fully preemptible kernel, both in userspace and kernel space. Like all preemptive kernels, of course, it is not preemptible when interrupts are disabled (since the clock interrupt can't happen). The main reason why NT has always been preemptive is because its always been SMP. The locking requirements on SMP are similar to to locking requirements for a preemptible kernel, so you can get both together for the price of one. Indeed, the preemptive patch for Linux is very small because it uses the existing SMP locking mechanism.

    --
    A deep unwavering belief is a sure sign you're missing something...
  40. Re:What is "preemtive" for ? by be-fan · · Score: 2

    Hey, I love BeOS as much as the next fanatic, but (as much as I would love to) I can't use it because its compiler is old and there is no support for the rear-channel on my SB Live!

    --
    A deep unwavering belief is a sure sign you're missing something...
  41. Re:Wow by sam@caveman.org · · Score: 2

    lately try using win 95 as a firewall/dns/router on a 386?

    have fun.

    -sam

    --
    burn the computers. go back to the abacus.