this post was submitted on 07 Jul 2024
839 points (92.7% liked)

linuxmemes

21172 readers
911 users here now

Hint: :q!

Sister communities:

Community rules (click to expand)

1. Follow the site-wide rules

2. Be civil
  • Understand the difference between a joke and an insult.
  • Do not harrass or attack members of the community for any reason.
  • Leave remarks of "peasantry" to the PCMR community. If you dislike an OS/service/application, attack the thing you dislike, not the individuals who use it. Some people may not have a choice.
  • Bigotry will not be tolerated.
  • These rules are somewhat loosened when the subject is a public figure. Still, do not attack their person or incite harrassment.
    • 3. Post Linux-related content
  • Including Unix and BSD.
  • Non-Linux content is acceptable as long as it makes a reference to Linux. For example, the poorly made mockery of sudo in Windows.
  • No porn. Even if you watch it on a Linux machine.
    • 4. No recent reposts
  • Everybody uses Arch btw, can't quit Vim, and wants to interject for a moment. You can stop now.

    • Please report posts and comments that break these rules!

    founded 1 year ago
    MODERATORS
    poopsmith@lemmy.world
    zephyr@lemmy.world
    rtxn@lemmy.world
    839
    No Mercy (files.catbox.moe)
    submitted 4 months ago by sag@lemm.ee to c/linuxmemes@lemmy.world
    162 comments fedilink hide all child comments
     
    you are viewing a single comment's thread
    view the rest of the comments
    [–] uis@lemm.ee 1 points 3 months ago* (last edited 3 months ago)

    First, this is an argument that derived from first generation microkernels, and in particular, MINIX, which - as a teaching aid OS, never tried to play the benchmark game.

    Indeed, first generation microkernels were so bad, that Jochen Liedtke in rage created L3 "to show how it's done". While it was faster than existing microkernels, it was still slow.

    One paper notes that, once the working code exceeds the L2 cache size, there is marginal advantage to the monolithic structure.

    1. The paper was written in pre-meltdown era.
    2. The paper is about hybrid kernels. And gutted Mach(XNU) is used as example.
    3. Nowdays(after meltdown) all cache levels are usually invalidated during context switch. Processors try to add mechanisms to avoid this, but they create new vulnreabilities.

    A second paper running benchmarks on L^4^Linux vs Linux concluded that the microkernel penalty was only about 5%-10% slower for applications than the Linux monolithic kernel.

      1. Waaaaay before meltdown era.

    I'll mark quotes from paper as doublequotes.

    a Linux version that executes on top of a first- generation Mach-derived µ-kernel.

    1. So, hybrid kernel. Not as bad as microkernel.

    The corresponding penalty is 5 times higher for a co-located in-kernel version of MkLinux, and 7 times higher for a user- level version of MkLinux.

    Wait, what? Co-located in-kernel? So, loadable module?

    In particular, we show (1) how performance can be improved by implementing some Unix services and variants of them directly above the L4 µ-kernel

    1. No surprise here. Hybrids are faster than microkernels. Kinda proves my point, that moving close to monolithic improves performance.

    Right now I stopped at the end of second page of this paper. Maybe will continue later.

    this blog entry

    Will read.