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Operating Systems Software BSD

ULE Now The Default Scheduler On FreeBSD 138

Posted by timothy from the ule-stole-my-prom-date dept.
Dan writes "FreeBSD's Jeff Roberson says that the ULE scheduler has entered into its probationary period as the default scheduler on FreeBSD. He says that if all goes well, it will remain the default through the rest of FreeBSD 5.* releases. He is requesting you to switch over and test it. The ULE scheduler was designed to address the growing needs of FreeBSD on SMP/SMT platforms and under heavy workloads. It supports CPU affinity and has constant execution time regardless of the number of threads."
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ULE Now The Default Scheduler On FreeBSD More

ULE Now The Default Scheduler On FreeBSD

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  • Good news (Score:5, Funny)

    by Zork the Almighty ( 599344 ) on Sunday January 25, 2004 @04:57PM (#8083100) Journal
    This is great news. The O(1) scheduler in Linux is awesome, and it's good to see FreeBSD keeping up. Now if we just had an O(1) way to squash *BSD trolls, Slashdot would be saved.

    • Re:Good news (Score:5, Interesting)

      by Bobas ( 581631 ) on Sunday January 25, 2004 @06:02PM (#8083414) Homepage
      I'm testing this scheduller now (option SCHED_ULE in kernel config) on GNOME desktop. You can really tell the difference, feels much "smoother" and "faster".

      Just my 2c.

    • Re:Good news (Score:3, Funny)

      by Homology ( 639438 )
      Now if we just had an O(1) way to squash *BSD trolls, Slashdot would be saved.

      There are fewer *BSD trolls than people inhabiting this planet. Thus there is indeed an O(1) way to squash them, albeith with a high coefficient baked into the O(1).

      However, the weak point of the above argument is the implicit assumption that trolls are people. Well, in a way they are, but they are somehow more like rabbits. And as we all know, a rabbit population is modelled by a Fibonacci serie, that, alas, is not even li

  • "a pathological case" (Score:5, Interesting)

    by bersl2 ( 689221 ) on Sunday January 25, 2004 @05:24PM (#8083238) Journal
    Quoted from the ULE paper (p.11):
    Figure 6 illustrates a pathological case for the Linux
    scheduler which early versions of ULE fell victim to.
    The setup is 5 nice -5 processes each attempting to use
    25% of the CPU. This over-commits the CPU by 25%,
    which should not be a problem. However, since Linux
    gradually reduces the priority until it hits the minimum,
    the nice value is enough to prevent even normal
    interactive tasks from running with reasonable latency.
    This was solved in ULE by using the interactivity
    scoring algorithm presented above.
    I didn't follow the development of the O(1) scheduler very closely. Has this been looked at since 2.5.56 (the version of Linux they cite)? Is this even true?
    • According to my understanding of the O(1) scheduler, this
      pathological case does not exist. However, my understanding
      is pretty weak, so could someone who knows please answer
      the parent post?

  • Does everyone know about GNU/KFreeBSD? (Score:5, Interesting)

    by ciaran_o_riordan ( 662132 ) on Sunday January 25, 2004 @05:31PM (#8083270) Homepage

    GNU/KFreeBSD [debian.org] is a project that doesn't get enough press.

    Most GNU systems use Linux as their kernel, but this doesn't have to be the case. The porting of GNU to the FreeBSD kernel is almost complete. (the project name changed from GNU/FreeBSD to GNU/KFreeBSD after a trademark discussion with some FreeBSD folks.)

    FreeBSD people say that their kernel is rock solid, has the best uptimes, most robust networking, and now it's getting an improved scheduler. So it would make sense for GNU users to considering using the FreeBSD kernel instead of Linux.

    Having everyone using the same kernel just makes life easier for worm writers, and corporate attacks such as the SCO fiasco.

    Of course, adoption will be hampered by the marketing mistake of calling the whole OS "Linux", but I hope that choice of kernels will become more normal in the future. It would also help if they came up with a friendlier name than "GNU/KFreeBSD" (8 sylabyls!).

    Anyway, I hope to start using the FreeBSD kernel soon.

    • Re:Does everyone know about GNU/KFreeBSD? (Score:2, Insightful)

      by Anonymous Coward
      uhhhh. why not just use FreeBSD? I mean, seriously, does every piece of software have to have GNU/before it? If you like the kernel so much, why do you assume the rest of the userland must suck? Any GNU tools you specifically need you can install from ports or packages anyway. Projects like this GNU/KFreeBSD are just a waste of developer time to make someones ego feel better. well, whatever.

      • Re:Does everyone know about GNU/KFreeBSD? (Score:5, Informative)

        by anthonyrcalgary ( 622205 ) on Sunday January 25, 2004 @08:59PM (#8084632)
        Well, they actually *do* help keep the GNU toolset portable and clean. Even if they aren't used, using the same stuff on more than one OS exposes problems before they become a remote root exploit.

        Sure I like BSD. Says so in my sig. But if someone else does things right, I'm not going to yell at them.

        Besides, with the GNU toolset on the FreeBSD kernel, you can set up a jail on the FreeBSD side, and then if you want both you can have both. There are differences, it's annoying sometimes, I'm sure some people want both.

        • Re:Does everyone know about GNU/KFreeBSD? (Score:5, Interesting)

          by scrytch ( 9198 ) <chuck@myrealbox.com> on Monday January 26, 2004 @10:34AM (#8087997)
          Besides, with the GNU toolset on the FreeBSD kernel, you can set up a jail on the FreeBSD side, and then if you want both you can have both. There are differences, it's annoying sometimes, I'm sure some people want both.

          Are you aware that /compat/linux will work just fine in a jail, and that the Linux distribution in there (you get your choice of redhat or debian) runs a rull suite of GNU utilities? And it's all at native speed, not emulated, it's going through the same syscall mapping layer that BSD itself uses.

          I'm all for porting the GNU toolchain to BSD, and so are a lot of other people, which is why it's already been done and is available in ports. Are you seriously talking about porting bloatsome abominations like glibc or something? (Oh wait, /compat/linux again, been done)

          • Re:Does everyone know about GNU/KFreeBSD? (Score:4, Interesting)

            by anthonyrcalgary ( 622205 ) on Monday January 26, 2004 @05:47PM (#8093596)
            Are you aware that /compat/linux will work just fine in a jail, and that the Linux distribution in there (you get your choice of redhat or debian) runs a rull suite of GNU utilities? And it's all at native speed, not emulated, it's going through the same syscall mapping layer that BSD itself uses.
            a) Going through the compatability layer won't do anything to keep GNU more portable. We're probably headed in the direction of every major OS having a Linux compatability layer... but that's just because Linux programmers don't think portable. That should be discouraged.

            b) Keeping the code portable means no porting is necessary, the makefiles will take care of it. Except for making it fit properly into the ports tree that is, but that's relatively trivial.

            c) Linux code can't use BSD specific stuff like kqueue. Portable code would handle that with ifdef's and so forth.
      • There is one big difference: here you have a Debian operating system running FreeBSD.

        Some people just love Debian, yet may be interested in running a FreeBSD kernel.

    • Why? (Score:5, Interesting)

      by bluGill ( 862 ) on Sunday January 25, 2004 @06:23PM (#8083550)

      I uise freeBSD everyday, and I have to ask why you would care about GNU/freeBSD. The utilities are essentially equivelent. There is a little more bloat (read features) in some of the GNU stuff. Nothing really significant though.

      Sure it is neat that they can do it. However to say everyone should want to run it? I don't get it.

      • Re:Why? (Score:4, Interesting)

        by CentrX ( 50629 ) on Monday January 26, 2004 @12:22PM (#8089290)
        Aside from being an experimental exercise, this is a part of the universal notion of Debian. In the future, one will be able to use a Debian system with the Linux and Free-, Net-, or OpenBSD kernels. Thus, Debian will offer a more universal set of options, and by the same processes that produce Linux-based Debian and its quality, stability, and security.
    • I have always wanted the software incompatibilities of the FreeBSD kernel with the nightmare that is the Linux userland. This project has answered my prayers!

      Seriously though, why on earth would you use this project? The biggest selling point of FreeBSD is that it is a tightly integrated system. Why would you want to break that up? More importantly, why would you want the more restrictive license included with Debian?

      -sirket
      • Yes, you like *BSD, I'm not trying to convert you or question your *BSD loyalty.

        I'm saying that the kernel of FreeBSD might be superior to Linux. And since GNU users consider both to be Free Software, they should consider giving the FreeBSD kernel a try.

        There's also a GNU/KNetBSD project, but it has less momentum.
    • You are aware that OpenBSD is working hard to get rid of all GPL code from userland since they don't concider GPL to be free enough? Similar sentiments you may find in the other *BSD.

      I see little benefit of this project, except trying to shove GPL down the troat of those that think that BSD license is good enough.

    • It would also help if they came up with a friendlier name than "GNU/KFreeBSD"

      Considering how little the FSF cares about how clumsy the "GNU/Linux" moniker is, I rather doubt we'll be seeing a different name anytime until the project dies from the awesome lack of interest from both BSD and Linux users.

      Some tools in the GNU toolchain are indeed superior to their BSD counterparts and are the default on BSD because of this (tar) or simply because there's no credible alternative (gcc, gzip). Others are avai

      • Re:Does everyone know about GNU/KFreeBSD? (Score:4, Informative)

        by phoenix_rizzen ( 256998 ) on Monday January 26, 2004 @12:33PM (#8089469)
        Most of these tools are being removed/replaced from the OpenBSD source tree. Several of these are also being removed/replaced from the FreeBSd source tree. Not sure if there are any projects along these line for NetBSD.

        Check out libtar, the BSD replacement for GNU tar. BSD awk and sed are also in the works, as is a BSD grep.

        • I totally agree with that OpenBSD is doing regarding the removal of GNU software. It seems as though the other BSD's are doing this, but I haven't read about that elsewhere do I don't know for sure. Although, I do hope they are following OpenBSD's lead. It would be nice to have a truely "free" (free in every sense of the word) Operating System.

        • most of your "in the works" projects have been around for a long time. you can easily use bsd pax as tar, as openbsd has done for years. awk and sed have always been from bsd. grep, diff, and gzip replacements are newer (for being included as default) however.
    • Anyone else besides me find it ironic to talk about GNU/{K}FreeBSD when RMS hated the (old) BSD license because of the "obnoxious advertising clause?"

      "Yeah, I hated that old obnoxious advertising clause, made binaries clunky" I wrote in an email on my Apache/mod_perl/PostgreSQL/CyrusIMAPD/XFree86/GNOM E/glibc/GNU/KFreeBSD machine....
  • According to this [kerneltrap.org], Con Kolivas suggests that the ULE scheduler is prone to the same problems that the Linux O(1) scheduler faced initially. Can someone with a more detailed knowledge of the workings of the ULE scheduler throw some light on this?

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