Zack's Kernel News
Zack's Kernel News
Chronicler Zack Brown reports Opcode life cycles and naming conventions.
Opcode Life Cycles
In the Mariana Trench of Linux kernel development swims the elusive yet luminescent creature, the opcode. Rarely seen by user eyes, the opcode forms the basis of the elaborate computer ecosystem upon which rests the digital life and productivity of our entire planet.
Opcodes exist at the hardware level. They are implemented by the actual AND, OR, and other silicon-based logic gates that exist by the millions on chips that run nearly every CPU in the known universe. Quantum computers, Babbage difference engines, and Antikythera devices are something else again – Linux support coming soon.
Steven Rostedt recently caught a glimpse of the rare and elusive cmpxchg opcode. This opcode compares and then potentially exchanges two values with one another, without allowing anything to interrupt it during the moment between the comparison and the actual data exchange. Ordinarily, in Linux and other multithreaded systems, operations are routinely interrupted by the kernel to provide that smooth and seamless feel of everyone using the system at the same time. The cmpxchg opcode makes this easier by preventing the interruption coming at an inconvenient moment, when the data might be in an inconsistent state. Otherwise, the kernel would have to implement a more complex and robust batch of code to do the same operation safely.
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
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
-
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.
-
Linux Kernel 6.14 Released
The latest Linux kernel has arrived with extra Rust support and more.