Kernel News
Zack's Kernel News
This month in Kernel News: Shared Processes with Hyper-Threading; Cleaning Up printk(); and Rust in the Kernel.
Shared Processes with Hyper-Threading
Joel Fernandes wanted to speed up hyper-threading by making it possible for processes on the same CPU that trust each other to share hyper-threads. Hyper-threading is Intel's proprietary form of hardware-based multithreading. Generally in Linux and other operating systems (OSs), the OS is responsible for switching rapidly between processes, so everything on the system seems to be running at once. Hyper-threading does this at the hardware level, saving time for the OS. But the OS can still interact with Intel's hyper-threading features, so folks like Joel can try to eke out performance improvements.
Joel specifically wanted to improve Peter Zijlstra's "core-scheduling" patches, which Peter famously hates the way one hates slowly pulling out their own fingernails. He actually did this once. No, not really. However, the point of the core-scheduling patches is to make each CPU act like two. This way, for moments when one of the virtual CPUs has nothing to do, the other virtual CPU will keep chugging away, making sure the hardware "real" CPU is as fully utilized as possible.
Of course, processes running on those two hyper-threading virtual CPUs have to be treated like potential security threats, the same as all processes everywhere. If a hostile actor gets into a user process on a given system, the kernel wants to limit the amount of damage that actor can do. That's just part of standard Linux procedure. Keep everything isolated, and then nothing can hurt anything else too badly.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.

News
-
System76 Releases COSMIC Alpha 7
With scores of bug fixes and a really cool workspaces feature, COSMIC is looking to soon migrate from alpha to beta.
-
OpenMandriva Lx 6.0 Available for Installation
The latest release of OpenMandriva has arrived with a new kernel, an updated Plasma desktop, and a server edition.
-
TrueNAS 25.04 Arrives with Thousands of Changes
One of the most popular Linux-based NAS solutions has rolled out the latest edition, based on Ubuntu 25.04.
-
Fedora 42 Available with Two New Spins
The latest release from the Fedora Project includes the usual updates, a new kernel, an official KDE Plasma spin, and a new System76 spin.
-
So Long, ArcoLinux
The ArcoLinux distribution is the latest Linux distribution to shut down.
-
What Open Source Pros Look for in a Job Role
Learn what professionals in technical and non-technical roles say is most important when seeking a new position.
-
Asahi Linux Runs into Issues with M4 Support
Due to Apple Silicon changes, the Asahi Linux project is at odds with adding support for the M4 chips.
-
Plasma 6.3.4 Now Available
Although not a major release, Plasma 6.3.4 does fix some bugs and offer a subtle change for the Plasma sidebar.
-
Linux Kernel 6.15 First Release Candidate Now Available
Linux Torvalds has announced that the release candidate for the final release of the Linux 6.15 series is now available.
-
Akamai Will Host kernel.org
The organization dedicated to cloud-based solutions has agreed to host kernel.org to deliver long-term stability for the development team.