Linux

After 20 years, Real-Time Linux (PREEMPT_RT) is finally -- finally -- in the mainline kernel. Linus Torvalds blessed the code while he was at Open Source Summit Europe. [...] The real-time Linux code is now baked into all Linux distros as of the forthcoming Linux 6.12 kernel. This means Linux will soon start appearing in more mission-critical devices and industrial hardware. But it took its sweet time getting here. An RTOS is a specialized operating system designed to handle time-critical tasks with precision and reliability. Unlike general-purpose operating systems like Windows or macOS, an RTOS is built to respond to events and process data within strict time constraints, often measured in milliseconds or microseconds. As Steven Rostedt, a prominent real-time Linux developer and Google engineer, put it, "Real-time is the fastest worst-case scenario." He means that the essential characteristic of an RTOS is its deterministic behavior. An RTOS guarantees that critical tasks will be completed within specified deadlines. [...]

So, why is Real-Time Linux only now completely blessed in the kernel? "We actually would not push something up unless we thought it was ready," Rostedt explained. "Almost everything was usually rewritten at least three times before it went into mainline because we had such a high bar for what would go in." In addition, the path to the mainline wasn't just about technical challenges. Politics and perception also played a role. "In the beginning, we couldn't even mention real-time," Rostedt recalled. "Everyone said, 'Oh, we don't care about real-time.'" Another problem was money. For many years funding for real-time Linux was erratic. In 2015, the Linux Foundation established the Real-Time Linux (RTL) collaborative project to coordinate efforts around mainlining PREEMPT_RT.

The final hurdle for full integration was reworking the kernel's print_k function, a critical debugging tool dating back to 1991. Torvalds was particularly protective of print_k --He wrote the original code and still uses it for debugging. However, print_k also puts a hard delay in a Linux program whenever it's called. That kind of slowdown is unacceptable in real-time systems. Rostedt explained: "Print_k has a thousand hacks to handle a thousand different situations. Whenever we modified print_k to do something, it would break one of these cases. The thing about print_k that's great about debugging is you can know exactly where you were when a process crashed. When I would be hammering the system really, really hard, and the latency was mostly around maybe 30 microseconds, and then suddenly it would jump to five milliseconds." That delay was the print_k message. After much work, many heated discussions, and several rejected proposals, a compromise was reached earlier this year. Torvalds is happy, the real-time Linux developers are happy, print_K users are happy, and, at long last, real-time Linux is real.

cross-posted from: https://lemmy.dbzer0.com/post/28037255

Hey hey people. Relatively new Arch user here, but not new to Linux in general. I've been using Arch with KDE Plasma on this HP laptop from 2013, and I've been enjoying it a lot after spending a long time on Mint/Cinnamon.

But, I've noted that KDE is a bit slow on this machine, and is probably a bit too much. Earlier today, I decided to try out something lighter, and installed LXQt on it as a second DE. The experience was okay, with much improved responsiveness, a nice customizable retro look, and overall simpleness that still did the job mostly. But I also ran into a few issues that probably had to do with having two different DEs on the same machine and user. One thing in particular ended up annoying me so much I went back to KDE: The Discover app would just refuse to play nice with setting a dark theme on the rest of the environment, even when I tried setting it up with qt6ct.

So now I'm considering going to XFCE instead, as I probably should have done from the beginning. I just wish it had Wayland support already (I know it's being worked on). Do you have any suggestions or tips for me in regards to this? I'm sure a lot of people will recommend their favorite tiling WM which I'm not sure I want to get into.

Also, other than that, upon returning to KDE, I found that my Discover would crash when trying to update Flatpaks (the only thing I install through it) and started thinking this experiment somehow broke it.... but it's Flatpak itself that seems to have an issue today. Might have to do with the latest curl update? Dunno if I should make a separate thread for that. https://discuss.kde.org/t/kde-discover-broken-with-latest-curl-update/21475

So, I was told you can take any distro, pair it with any desktop environment, and badda bing, badda boom, unique linux in the room!

And a few years ago I tried getting into linux, and it didn't work. I didn't like ubuntu. I want something that's basically like Windows 98.

Closest thing I found was TwisterOS. Well, I had some issue with one program, and I'm an idiot on linux. Have no clue what I'm doing. So the guides tell me to update the thing. So I do that, and the fan in my case stops working. Aye-yi-yi!

I never got it to start working again, and I just said screw it, I'm not dealing with this. Put it in a drawer, and haven't touched it in about a year.

Well, now I'm think I'll just start fresh. Install a new distro, and since Ubuntu seems to be the one with the most support, I'll use that. Then I find out that LXDE visually is more in line with what I want.

So I figure I'll slap on ubuntu, slap on LXDE, and then install retropie. And hopefully the fan will work again. So I start researching this LXDE, and the home page wants you to download the desktop environment already baked into a DIFFERENT distro! Wait, hold on. Am I wrong in thinging you can just download a desktop environment, and slap it on any distro? Because it might be me. I have no clue what I'm doing. And even though this is lemmy, when I searched for "Ubuntu Help", there's no community named that. There's also no community named "Linux help". Which I find very very odd. Lemmy of all places you'd think would have a linux help community! This place loves linux. Does everyone just always know what they're doing at all all times? Or am I just going crazy? I feel like I'm walking blind into a forest and bear traps line the ground. I have no idea how to even start this process....

Here is the needed desktop file

Place it in ~/.local/share/applications/

Right click the Dolphin icon and select a profile!

cross-posted from: https://lemmy.ml/post/20329962

Linus has released the 6.11 kernel. ""I'm once again on the road and not in my normal timezone, but it's Sunday afternoon here in Vienna, and 6.11 is out."" Significant changes in this release include new io_uring operations for bind() and listen(), the nested bottom-half locking patches, the ability to write to busy executable files, support for writing block drivers in Rust, support for atomic write operations in the block layer, the dedicated bucket slab allocator, the vDSO implementation of getrandom(), and more. See the LWN merge-window summaries (part 1, part 2) for more information.

Here is the guide as text

The Linux Mint project has at times forked various open-source projects to evolve them on their own such as the Cinnamon desktop starting out as forks of several GNOME 3 components. While their software forks and focus has mostly been at the desktop-level, they are going a bit further down the stack now to develop forks of several APT components that power package management on Debian/Ubuntu systems.

linked from: https://programming.dev/post/19267200

In its current plan, the EU commission intends to cut €27 million in funding for Free Software. The article has a link to a questionnaire that you can fill out and express your opinion about the plan. I believe non-EU citizens can participate as well.

Radicle is an open source, peer-to-peer code collaboration stack built on Git. Unlike centralized code hosting platforms, there is no single entity controlling the network. Repositories are replicated across peers in a decentralized manner, and users are in full control of their data and workflow.

Linux maintainers are unwilling to get rust into the kernel, so some rust folks decided to start writing a new kernel with same ABI. This allows them to make new architectural decisions. An example being their "frame kernel" (something between a monolithic kernel and a microkernel).

If I may say, it's more legible and the tooling is way better, right off the bat.

Awesome talk by Jay Lacroix:

about his life from a poor boy walking to a payphone in the rain, to call Microsoft to unlock his Laptop - to a Linux sysadmin who uses the time frame for all his certificates as a motivator, because he has ADHD!