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Linux Kernel Performance How Will 2.6 Measure Up?

An anonymous reader writes "This story offers some interesting performance comparisons between the latest stable Linux kernels (2.4.x) and the latest development Linux kernels (2.5.x), comparing performance on both a single processor and dual processors. These numbers help validate that the upcoming 2.6 kernel will outperform the current 2.4 kernel, at least in some instances..."

16 of 177 comments (clear)

  1. Compile time speedups by IamTheRealMike · · Score: 5, Interesting
    The thing I'm most looking forward to is the better scheduling under heavy disk load. This'll hopefully make Linux a lot more responsive when compiling software, at the moment my machine can get bogged down and jerky when doing this.

    Of course, the real solution would be to not need to compile software (plug plug :)

    1. Re:Compile time speedups by Anonymous Coward · · Score: 3, Interesting

      Amazing, I've been running FreeBSD since 2.8 and I've never had an unresponsive system even while doing a build world; I guess the 2.4 kernel is alot worse than imagined.
      Hopefully it will be solved for you Linux guys in 2.6.

    2. Re:Compile time speedups by cras · · Score: 2, Interesting

      I've tried 2.5.48 and 2.5.49 and gave up both mostly because when compiling software Galeon got horribly slow especially with scrolling, MUCH worse than 2.4 kernels. Giving smaller priority to compiling job made it better but I'm too lazy to type the extra nice command before make..

    3. Re:Compile time speedups by pkplex · · Score: 4, Interesting

      Yep.

      I first tried FreeBSD about a month ago, and thats exactly what I noticed about FreeBSD. Smooooooooth.

      For example in Linux ( 2.2.x and 2.4.18+ ) I found that when something demanding was going on ( like building mozilla, kernel, or such like ), all X11 became all choppy ( Mouse stuttered, typing lagged in bursts ).

      Not so with FreeBSD. Many times ive had GnomeICQ hit a bug and use 100% cpu, but I was unaware of this until days later when looking at top.

      A few days ago I installed FreeBSD onto my p100, with 64Mb of ram. Playing around, I ran many many dnetc's by having thousands of 'nohup ./dnetc &' lines in a file and executing it.

      At a load of 350 the p100 box was still very happy to do what I told it, and with very suprising responsivness. However, once the load got up to 450, my ssh connection to the box was terminated, and I had to restart sshd locally. Which is fair enough, I guess.. one will run out of swap and ram sooner or a later.

      I can recall doing this same dnetc thiwith slackware, running 2.4.something, and after a short while at load 50, I started getting seg faults every time I ran a command.

      Untill Linux shurgs off huge loads effortlessly and in a stable manner like FreeBSD does, its not going to live in my boxen :)

      Tux needs to get fit and learn how to balance on one leg properly :)

  2. Quick question by Anonymous Coward · · Score: 5, Interesting

    What is the weakest specced machine that anyone here is getting productive/useful work with Linux done on? Do people use Linux on 468s at 12mhz? P75s? Just curious.

    1. Re:Quick question by Anonymous Coward · · Score: 1, Interesting

      i am runing redhat 7.0 with a vanilla kernel 2.4.19 on a hp vectra 486 at 66hmz.

      it is not the ultra fastest server in the world, but i use it as a router for my adsl/cable connection. and i am very happy with it.

    2. Re:Quick question by freedom_leffo · · Score: 1, Interesting

      Well, I'm still using my overclocked 486SX/25 (now at 33 MHz) with 16 MB RAM everyday. It's running a distribution built from scratch (http://www.linuxfromscratch.org) and it has got all the speed I need.

    3. Re:Quick question by mvdw · · Score: 2, Interesting

      I have on my network at home the following ancient hardware:

      • 486-DX 33 w/32MB RAM, running as dialup firewall for 2-3 users;
      • 386-DX40 (with 387 co-pro), 20MB RAM, running slackware 8.0 (kernel 2.2.19 I think, although to be honest I don't turn it on all that often). I use this machine basically as a scsi box to format external scsi disks for my HP PA/RISC adventures.

      I also have some other odd hardware on my network, that is so ancient that linux won't even run on it (2 DEC turbochannel machines, one MIPS-based and one Alpha, both running netBSD)...

      I acquired all this hardware when it was being thrown out by various people - bang per buck is essentially infinite

    4. Re:Quick question by Anonymous Coward · · Score: 1, Interesting

      No, but the very first 386s were 14.7MHz. The initial target was 16MHz. They followed soon afterwards. I remember when the 386/25 came out :-) Ah, those were the days :-)

  3. It may be faster... by cperciva · · Score: 4, Interesting

    but will it corrupt my filesystem?

    Performance is important, certainly, but I think some people (*cough* overclockers *cough*) assign it a bit too much importance.

  4. BSD? by pkplex · · Score: 4, Interesting

    I wonder how well it compares to the BSD kernels, in both performance and stability?

    1. Re:BSD? by Xpilot · · Score: 1, Interesting

      I wonder how well it compares to the BSD kernels, in both performance and stability?

      I was wondering that myself. The *BSD's are more or less "distros" complete with userland tools whereas Linux is just a kernel. The complete OS+tools should be called GNU/Linux (as RMS insists).

      Whenever I see posts that say "*BSD is better than Linux", most of the time they are referring to some userland aspect of *BSD compared to some GNU/Linux distro, and not "Linux" the kernel itself. Which isn't really fair IMHO, since most of the time it's not "Linux"'s fault for whatever is being bashed at the time.

      --
      "Backups are for wimps. Real men upload their data to an FTP site and have everyone else mirror it." -- Linus Torvalds
  5. SMP is overrated by g4dget · · Score: 3, Interesting
    Yes, there is some market segment that really swears by SMP. But beyond dual processor machines, the hardware cost and engineering complexity grow disproportionately with the number of processors. Most of the SMP market is driven by companies facing excessive software license costs for multiple machines, or by companies that can't figure out how to get their current architecture ported to a cheaper distributed system.

    When it comes down to it, you only get cost-effective scalability by using distributed systems or clustering. In fact, for really large systems, it's the only possible way at all.

    Something like OpenMosix should really be a standard part of the Linux kernel already, as should other support for simplifying clustering, distributed computing, communications, and distributed shared memory. Distributed systems and clustering is the future, not SMP.

  6. People in glasshouses shouldn't throw stones by marm · · Score: 5, Interesting

    Amazing, I've been running FreeBSD since 2.8 and I've never had an unresponsive system even while doing a build world; I guess the 2.4 kernel is alot worse than imagined.

    This is, by and large, the fault of the scheduler, largely unchanged in 10 years and described by Linus, even whilst he wrote it, as a 'hack'. However, it worked, and Linus, being the extremely sensible and conservative maintainer that he is, kept it until recently - process schedulers are difficult things to get right, and their performance is crucial to the performance of the kernel as a whole. Not to mention that for the tasks that Linux has been used for historically, primarily low-volume server tasks on low-end hardware, it isn't really a bottleneck.

    Still, the scheduler has been gutted and rewritten for 2.6 by Ingo Molnar - the now somewhat-famous O(1) scheduler, which performs much more fairly under load, and dispenses with almost all of the strange pauses and scheduling glitches under load. Current vendor kernels based on 2.4 (Red Hat's and SuSE's at least, I think) have had the O(1) scheduler backported to them as well. In fact, if you're running near enough any current 2.4 kernel other than mainline, you get the O(1) scheduler and your share of scheduling fairness.

    The new scheduler is also a fundamental basis for Linux 2.6's new NPTL 1:1 threading, which has so far proved spectacularly (record-breakingly?) fast. Hmm, on second thoughts, perhaps I probably shouldn't mention threads and FreeBSD in the same post. I mean, isn't this the same FreeBSD that's still waiting for a single half-decent pthread implementation? Oh well, better hope 5.0 is out soon...

  7. Logical Volume Manager? by Hoblin · · Score: 2, Interesting

    I'm looking forward to the network failover and I/O failover features. The Device Manager looks pretty, too. But, when are they going to provide an friggin' LVM? Optimizations are great, but I want features, Damnit!

    1. Re:Logical Volume Manager? by router · · Score: 2, Interesting

      They are working on LVM, and EVMS (userland) is going to work with 2.5/6 like it does for 2.4. If you need more LVM than EVMS, you are crazy. Also, what network failover is new? 2.4 supports channel bonding (read Documentation/networking/bonding.txt) and also supports just about everything you could possibly imagine wrt networking via iptools (read the lartc howto).
      Features are the one thing Linux doesn't lack, its got so many tools that, outside of custom applications with extreme requirements, it can basically do anything. Oh, also, can't run freakish proprietary code from monopolists, but what can?
      In short, these guys are good, and there is so much under the hood that is really incredible (and has been there for so long....) that outside of vendors supporting their own hardware (like they do for Win) with drivers (GPL please) there is little that is necessary to add to the linux kernel. Not that I don't applaud them trying, or would I stand in the way of a cool hack.
      They are even trying to put a generic crash dump capability in that allows userland to dump kernel cores to:
      Filesystem of your choice
      Serial console
      Network device of your choice
      Other server
      etc etc
      Amazing stuff. Just freaking amazing. If you haven't looked over the capabilities of the kernel lately, you owe it to yourself to do so.

      andy