Canonical announces the general availability of an enterprise-grade real-time Ubuntu kernel for Ubuntu 24.04 LTS (Noble Numbat) systems.

To get started with the real-time kernel for Ubuntu 24.04, check out the official documentation. One thing to keep in mind if you’re an NVIDIA GPU user is that the real-time Ubuntu kernel does not support the proprietary NVIDIA graphics drivers.

  • atzanteol@sh.itjust.worksEnglish
    0·
    5 months ago

    So, contrary to what it seems a single CPU core can only execute a single “thing” at a time. Modern operating systems do something called “preemptive multitasking” to give the illusion that more than one things are running at a time. The OS will start your task, then after a while save its state and start another task running, then switch back. It does this fast enough that each job seems to be running concurrently.

    Now if you’re running on a RaspberryPI your program might be waiting for input from a GPIO pin. And when you get that input you want to turn on some switch. Maybe an important switch. BUT It could be that your application is in the “paused” state when that pin gets input which will cause a delay between when the pin is trying to send you input and when you actually process it.

    A real-time OS minimizes such delays (latency) so that you can respond quickly.

    • applepie@kbin.social
      0·
      5 months ago

      I guess i am still skipping on how real time kernel address the pause? it just never pauses or it no longer needs to be paused?

      as a side note, is this similar technology they use in high precision manufacturing?

      • gorysubparbagel@lemmy.world
        2·
        5 months ago

        Think of it like a club with a max capacity of 10 people, where some people have VIP cards. If a person with a VIP card wants to get into the club, the bouncer will kick out one of the people inside that doesn’t have a VIP card to make space for them.

        For a more technical explanation:

        There are several processors on computers and each can be in use by 1 process at a time. Different processes can get different amounts of time based on their priority (called niceness in Linux) and they’ll be removed from the processor once their time is up until their next share of time.

        On a real-time kernel some processes are marked as real-time (certain range of niceness values, can’t remember the exact range). If a process that is real-time says it needs some processor time, a process that isn’t real-time that’s currently running will be immediately ripped off the processor to make room for the real-time process.