Slashdot Mirror

← Back to Stories (view on slashdot.org)

Preemptible Linux Kernel: Interviews and Info

Posted by michael on from the patch-and-patch-again dept.

An anonymous submitter sends: "MontaVista and Robert Love are developing a patch for the Linux kernel to make it fully preemptible. Lots of users are involved, and tests show huge reductions in latency. Robert's kernel patches are here. Finally, an interview with Robert, on preemption and more."

6 of 238 comments (clear)

  1. needed badly by xah · · Score: 4, Insightful
    A fully preemptible kernel is important to the future of Linux. Everyone knows that the system will lock up a lot if it's misconfigured, or if a piece of hardware is buggy.

    So long as the console driver and the keyboard driver are alive, root should always be able to open a new shell and kill an offending process that is hanging the rest of the system. Right now, this is too frequently a non-option.

    --
    I am not a lawyer. Do not take my words as legal advice. If you need legal advice, consult an attorney.
    1. Re:needed badly by Anonymous Coward · · Score: 1, Insightful

      Confusion again about the terms.. The only way bad software takes down the system right now is if it runs the machine out of an available resource (such as ram)

      Pre emptive kernel will NOT help this case.

    2. Re:needed badly by chabotc · · Score: 5, Insightful

      Actualy 9 out of 10 cases when that happens, and the hardware is locked up, it will have locked up the PCI bridge as well (they have to to communicatie), so this wont do anything.

      Also if the systeem feels locked up, and its not a hardware lock, there's a good chance its the tty/console subsystem thats killed.

      only in a few cases, where a run-away process would deal out so much of a beating to the system, then the better multithreading will help in the way you described.

      (ps, telnetting in is always a good work around for a system with a dead keyboard/console :P)

  2. Re:Microsoft Anthrax attacks by Anonymous Coward · · Score: 1, Insightful
    Is it a Worm, is it a Virus, does it use Outlook?

    Its a Virus.

  3. Re:yes, but why? by Spy+Hunter · · Score: 4, Insightful
    this has nothing to do with audio playback, which has no latency sensitivity (because of buffering)

    Unless you're writing a game, where sounds have to happen at specific times synchronized with events on-screen. Or you're in KDE and you want a "minimize" sound effect to happen when you press the button, not a second afterward. Or you're writing a media player and you want to have an EQ that responds immediately rather than a second from now, making it a tedious chore to adjust the settings.

    Large latency is very noticable in these situations. While it may sound like pointless whining to complain about the "minimize" sound effect being a second late, it really creates a bad perception in the user's mind about the speed of KDE. These things are actually important.

    --
    main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
  4. Re:Preempt Patches in Kernel by richie123 · · Score: 2, Insightful

    No, I thinks its more like Linux is saying he would rather make Linux faster, than make it feel faster.