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
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
-
Kali Linux Waxes Nostalgic with BackTrack Mode
For those who've used Kali Linux since its inception, the changes with the new release are sure to put a smile on your face.
-
Gnome 50 Smooths Out NVIDIA GPU Issues
Gamers rejoice, your favorite pastime just got better with Gnome 50 and NVIDIA GPUs.
-
System76 Retools Thelio Desktop
The new Thelio Mira has landed with improved performance, repairability, and front-facing ports alongside a high-quality tempered glass facade.
-
Some Linux Distros Skirt Age Verification Laws
After California introduced an age verification law recently, open source operating system developers have had to get creative with how they deal with it.
-
UN Creates Open Source Portal
In a quest to strengthen open source collaboration, the United Nations Office of Information and Communications Technology has created a new portal.
-
Latest Linux Kernel RC Contains Changes Galore
Linux kernel 7.0-rc3 includes more changes than have been made in a single release in recent history.
-
Nitrux 6.0 Now Ready to Rock Your World
The latest iteration of the Debian-based distribution includes all kinds of newness.
-
Linux Foundation Reports that Open Source Delivers Better ROI
In a report that may surprise no one in the Linux community, the Linux Foundation found that businesses are finding a 5X return on investment with open source software.
-
Keep Android Open
Google has announced that, soon, anyone looking to develop Android apps will have to first register centrally with Google.
-
Kernel 7.0 Now in Testing
Linus Torvalds has announced the first Release Candidate (RC) for the 7.x kernel is available for those who want to test it.