Linux Kernel 6.12 Has Been Released

Slashdot unixbhaskar writes: Linus has released a fresh Linux kernel for public consumption. Please give it a try and report any glitches to the maintainers for improvement. Also, please do not forget to express your appreciation to those tireless folks who did all the hard work for you.
The blog OMG Ubuntu calls it "one of the most biggest kernel releases for a while," joking that it's a "really real-time kernel." The headline feature in Linux 6.12 is mainline support for PREEMPT_RT. This patch set dramatically improves the performance of real-time applications by making kernel processes pre-emptible — effectively enabled proper real-time computing... Meanwhile, Linus Torvalds himself contributes a new method for user-space address masking designed to claw back some of the performance lost due to Spectre-v1 mitigations.

You might have heard that kernel devs have been working to add QR error codes to Linux's kernel panic BSOD screen (as a waterfall of error text is often cut off and not easily copied for ad-hoc debugging). Well, Linux 6.12 adds support for those during Direct Rendering Manager panics...

A slew of new RISC-V CPU ISA extensions are supported in Linux 6.12; hybrid CPU scaling in the Intel P-State driver lands ahead of upcoming Intel Core Ultra 2000 chips; and AMD P-State driver improves AMD Boost and AMD Preferred Core features.
More coverage from the blog 9to5Linux highlights a new scheduler called sched_ext, Clang support (including LTO) for nolibc, support for NVIDIA's virtual command queue implementation for SMMUv3, and "an updated cpuidle tool that now displays the residency value of cpuidle states for a clearer and more detailed view of idle state information when using cpuidle-info." Linux kernel 6.12 also introduces SWIG bindings for libcpupower to make it easier for developers to write scripts that use and extend the functionality of libcpupower, support for translating normalized error addresses reported by an AMD memory controller into system physical addresses using a UEFI mechanism called platform runtime mechanism (PRM), as well as simplified loading of microcode patches on AMD Zen and newer CPUs by using the family, model, and stepping encoded in the patch revision number...

Moreover, Linux 6.12 adds support for running as a protected guest on Android as well as perf and support for a bunch of new interconnect PMUs. It also adds the final conversions to the new Intel VFM CPU model matching macros, rewrites the PCM buffer allocation handling and locking optimizations, and improves the USB audio driver...

"Please give it a try..."

[Valgrus Thunderaxe]

"...and report any glitches to the maintainers for improvement."

If you want to get publicly flamed, just try that.

PREEMPT_RT

[VaccinesCauseAdults]

Why not call it PREEMPT_REALTIME? What’s with the 1970s C abbreviations?

Re:

[fahrbot-bot]

Why not call it PREEMPT_REALTIME?

That one's used to cut-off Bill Maher [wikipedia.org]. :-)

Re:

[VaccinesCauseAdults]

Okay I’ll pay that.

Re:

[backslashdot]

Memory is expensive .00000000001 cents per byte these days. That quickly adds up when you have billions of devices.

Re:

[VaccinesCauseAdults]

It is a kernel build-time configuration flag for enabling or disabling code paths via conditional compilation (preprocessor macro). It doesn’t ship on billions of devices.

Re:

[bn-7bc]

Is is really this cheap when uou neeed/want a TB+ in a single server?

Linux Preempting

[TheRealMindChild]

Robert Love created and released realtime patches way back in the 2.4 kernel days. There was nothing wrong with them, either.

https://www.kernel.org/pub/lin... [kernel.org]

Re:

[NoWayNoShapeNoForm]

And his patches were not brought into the Linux kernel "mainline"?

I guess rml got no love from the larger Linux development world, eh?

Re:

[drinkypoo]

Robert Love created and released realtime patches way back in the 2.4 kernel days. There was nothing wrong with them, either.

Turning on preempt with no other changes will often cause problems. I've tried it a few times and every time something got worse. Sometimes audio latency, sometimes a driver would start crapping out. The same kinds of stuff it's supposed to fix, in fact. Having preempt mainlined means more users which means more discovery of and fixes for these glitches.

https://bbs.archlinux.org/view... [archlinux.org]
https://forums.ni.com/t5/LabVI... [ni.com]
https://forums.debian.net/view... [debian.net]
https://community.vcvrack.com/... [vcvrack.com]

Only some of these probl

Re:

[thegarbz]

So to be clear, your theory is that someone with malicious intent goes in to compromise a critical piece of infrastructure at a root level to plant a bit of code in the hope that it causes an administrator to scan a QR code and not notice that it contains a malicious link instead of the crash report, all for the hope of what ... compromising a critical piece of infrastructure?

What's you're next plan? Break a window in someone's house and wait there with a gun for them to show up just so you can ask them for

Intel/AMD whatever, how is Apple Silicon improved?

[drnb]

Enough about legacy CPUs. What does this update mean for ARM and in particular Apple Silicon?

Re:

[ArchieBunker]

Sir this is slashdot, you’re not supposed to like Apple.

Windows ARM binaries are out

[drnb]

Sir this is slashdot, you’re not supposed to like Apple.

I actually like Windows, Linux and macOS. Different tools for different jobs.

Plus Windows is once again not limiting itself to x86, ARM binaries are out.

Re:

[DrMrLordX]

Apple needs to play nice and open up their hardware to alternative operating systems. Asahi makes do as best it can, supporting only M1 and M2.

Re:Intel/AMD whatever, how is Apple Silicon improv

[vbdasc]

Apple doesn't need that. They don't give a rat's azz about alternative operating systems, and never did. What they really need is to keep their users locked in the pen, walled garden or whatever. And they excel in that art.

Linux can't support something whose owner doesn't want it supported by Linux. At best, you get hackers who reverse-engineer the closed parts and create something like Asahi Linux, but it's not a sustainable solution and can't be officially supported.

Old Macs run Linux just fine

[drnb]

Apple doesn't like that they want you to throw away that old Mac and buy a new one when they tell you to do it!

Old Macs that no longer receive macOS updates boot and run Linux very well. I'm confident Linux will have the M4 figured out by the time they no longer receive macOS updates.

Re:

[DrMrLordX]

If drnb wants Linux kernel developers to start taking Apple hardware seriously, then Apple absolutely needs to open up their hardware.

Re:

[drnb]

If drnb wants Linux kernel developers to start taking Apple hardware seriously, then Apple absolutely needs to open up their hardware.

The roadblock is the Linux developers. They won't sign an NDA like Microsoft, so they don't get boot camp support like Microsoft did. Note MS's exclusive agreement with Qualcomm would seem to prevent such cooperation for now, that agreement is supposedly about to expire.

Apple also provides a virtualization framework that runs Linux. Linux runs just fine on the Apple Desktop as a result.

Re:

[DrMrLordX]

Why should they need to sign an NDA? They didn't sign NDAs with Intel or AMD.

Re:

[drnb]

Why should they need to sign an NDA?

They want access to proprietary info.

Re:

[drinkypoo]

If Apple wants to sell more hardware, they will make more of it open.

I don't know whether they particularly care right now how many units of hardware they sell, I would think they want more to sell people on a whole ecosystem of stuff. I doubt very much that Linux users will buy as many of their branded accessories as the average if they can use whatever they want with the machine.

Re:

[drnb]

If Apple wants to sell more hardware, they will make more of it open.

Apple's virtualization framework runs Linux quite nicely on the macOS desktop. Booting natively would be a largely niche activity even in the Linux community. Many Linux devs are pretty happy with macOS. Very little FOSS software is Linux specific, it's mostly POSIX and macOS is natively POSIX. Nearly everything builds and runs just fine. Linux more of a test platform than a dev platform as a result. Ubuntu, Debian and Fedora running on the macOS desktop makes this testing pretty convenient.

Re:

[drinkypoo]

Apple's virtualization framework runs Linux quite nicely on the macOS desktop.

whoopee

Booting natively would be a largely niche activity even in the Linux community.

Unless you want an OS that doesn't suck.

Many Linux devs are pretty happy with macOS.

And there are millions of Windows users with even lower standards.

Nearly everything builds and runs just fine.

Apple's approach, which can be summed up as "we get in the way of everything", is actively user-hostile and the enemy of performance. If I want to run Linux, why should I need another OS in between interfering with my access to hardware? If I want to display some graphics, why should it have to be done through Metal?

Linux more of a test platform than a dev platform as a result.

Sure, if you're happy with the inferior UI that resulted from Apple taking a perf

Re:

[drnb]

Apple has the superior interface. Apple's environment delivers both the commercial world and FOSS. Apple only gets in the way of FOSS politics, not end user performance nor experience.

Apple has, and does support, other OS

[drnb]

Apple doesn't need that. They don't give a rat's azz about alternative operating systems, and never did.

Wrong, twice over.

(1) They have offered Boot Camp to boot Windows on Intel for a long time. Supposedly the only reason they are not doing so with ARM for the moment is an exclusive deal with Qualcomm. One that is about to expire.

(2) Their virtualization framework in macOS supported console Linux for a while and more recently GUI Linux.

Re:

[antdude]

Like Apple doesn't care to keep providing Bootcamp for Windows in their ARM Macs. :(

Re:

[Quantum gravity]

How about: https://linuxsimply.com/best-l... [linuxsimply.com] ?

Re:

[vbdasc]

Okay, how about it? Aside from the fact that the article you linked has an informational value close to zero, and looks like it's written by an AI, it contradicts nothing in your parent comment.

The fact is that native Apple Mac hardware at the moment is not open enough to be properly supported by Linux period. You can install ANY Linux distro in a virtual machine on your Mac without major difficulties, but it will use a generic Linux ARM kernel. The guys at Asahi Linux are working hard to reverse-engineer

Re:

[drnb]

Asahi won't sign an NDA like Microsoft did to get access and help.

Apple provides a virtualization framework that runs Linux just fine on the Apple Desktop. Much like the Windows Subsystem for Linux.

Re:

[vbdasc]

Ah, now we're speaking.

Asahi can't sign an NDA and at the same time provide open-source code to the public. The latter would violate the former. It's the same with Linux. That's why Linux will never support Apple silicon directly until Apple changes its policy. Or Linux becomes closed-source, which hopefully will never happen.

Yes, Linux runs in a virtual machine on an ARM Mac. This just means that Linux is a second-class citizen on a Mac, just as it is in the WSL. Conversely, there won't be any specific sup

Re:

[drnb]

Asahi can't sign an NDA and at the same time provide open-source code to the public.

Closed binary blobs for Linux drivers are nothing new. It's more a matter of Asashi won't than can't. It's Asashi's decision.

Or Linux becomes closed-source, which hopefully will never happen.

It already happened. You never selected an option to allow non-open drivers during installation? I have, it was the only way to get Linux dual booting on a school selected Dell laptop I had to use.

Yes, Linux runs in a virtual machine on an ARM Mac. This just means that Linux is a second-class citizen on a Mac, just as it is in the WSL.

Alternatively it runs as a guest rather than a host and better integrates the two operating system desktops. Allowing a user to more seamlessly utilize the commercial and the open source. Co

Re:

[drnb]

Writing drivers, yes, they did so for Microsoft Windows. They probably already have a bit of the code written given that their virtualization framework runs GUI Linux just fine on the Apple Desktop.

Share their internal docs, I'm sure they would if Asashi would sign an NDA like Microsoft did.

Re:

[Bert64]

With intel macs 99% of the hardware was not apple specific, and already had windows drivers. All they did was bundle them together.

Re:

[drnb]

With intel macs 99% of the hardware was not apple specific, and already had windows drivers. All they did was bundle them together.

There were also drivers for Apple specific hardware written by Apple, Boot Camp installs those automatically after Windows is installed. When Microsoft's Qualcomm exclusive deal expires I am expecting to see a Boot Camp for ARM from Apple. Its a minor effort on their part, easily paid for by removing the "PC or Mac" decision from the potential buyers mind.

Re: Intel/AMD whatever, how is Apple Silicon impro

[vbdasc]

Linux is an open collaborative project. You are welcome to participate in improving its ARM support, and in particular, to petition Apple to provide open specifications of their hardware, so it could be properly supported by open-source OSes.

Or petition Asashi to sign an NDA

[drnb]

Or petition Asashi to sign an NDA, like Microsoft, to gain access. 3rd party closed drivers for Linux are a reality.

Re:

[bn-7bc]

Not to mention RISC-V, ARM is not exactly new, or open for that matter

Re:

[drnb]

Not to mention RISC-V, ARM is not exactly new, or open for that matter

Looking forward to it. Bur right now I'm only fooling around with RISC-V via ESP32 and Raspberry Pi Pico.

It would be really interesting if the full Raspberry Pi (an embedded Linux SBC) got some optional RISC-V cores like the Pico microcontroller did. If unfamiliar, Pico 2 has two ARM cores and two RISC-V cores. It recognizes whether the its executable code is ARM or RISC-V and hands the code off to the appropriate cores.

Re:

[test321]

What does this update mean for ARM

According to the merge summary from LWN:
* "The Arm "permission overlay extension" feature is now supported, making memory protection keys available on that architecture." https://lwn.net/Articles/82655... [lwn.net]
* "The Loongarch, 64-bit Arm, PowerPC, and s390 architectures have all gained support for the vDSO implementation of the getrandom() system call." https://lwn.net/Articles/98318... [lwn.net]

Re:

[serafean]

Apple Silicon is mainly updated through a branch https://github.com/AsahiLinux/... [github.com] , ofc with merges back to mainline.
Linux on Apple means Asahi Linux. There are pretty much no other options.

Re:

[drnb]

Linux on Apple means Asahi Linux. There are pretty much no other options.

For bootable Linux. Apple does offer a virtualization framework that runs GUI Linux on the macOS desktop.

Classism!

[Gravis Zero]

Also, please do not forget to express your appreciation to those tireless folks who did all the hard work for you.

I will show my appreciation by purchasing tires for the tireless programmers that have worked on making Linux possible but I have to say, it seems really rude to point out that some kernel programmers can't afford tires to wear. BTW, when did wearing tires become en vogue? Are they like, bicycle tires or should I be walking around with a Goodyear around my waist?

One of the most biggest.

[Gavino]

Bro, do you even grammar?

Re:

[BadgerStork]

It is in the linked article so ...

"Linus Torvalds has announced the release of Linux kernel 6.12, and an eclectic assortment of changes contained within make it one of the most biggest kernel releases for a while"

Thanks to all involved

[2TecTom]

World Class Effort