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
-
CachyOS Now Lets Users Choose Their Shell
Imagine getting the opportunity to select which shell you want during the installation of your favorite Linux distribution. That's now a thing.
-
Wayland 1.24 Released with Fixes and New Features
Wayland continues to move forward, while X11 slowly vanishes into the shadows, and the latest release includes plenty of improvements.
-
Bugs Found in sudo
Two critical flaws allow users to gain access to root privileges.
-
Fedora Continues 32-Bit Support
In a move that should come as a relief to some portions of the Linux community, Fedora will continue supporting 32-bit architecture.
-
Linux Kernel 6.17 Drops bcachefs
After a clash over some late fixes and disagreements between bcachefs's lead developer and Linus Torvalds, bachefs is out.
-
ONLYOFFICE v9 Embraces AI
Like nearly all office suites on the market (except LibreOffice), ONLYOFFICE has decided to go the AI route.
-
Two Local Privilege Escalation Flaws Discovered in Linux
Qualys researchers have discovered two local privilege escalation vulnerabilities that allow hackers to gain root privileges on major Linux distributions.
-
New TUXEDO InfinityBook Pro Powered by AMD Ryzen AI 300
The TUXEDO InfinityBook Pro 14 Gen10 offers serious power that is ready for your business, development, or entertainment needs.
-
LibreOffice Tested as Possible Office 365 Alternative
Another major organization has decided to test the possibility of migrating from Microsoft's Office 365 to LibreOffice.
-
Linux Mint 20 Reaches EOL
With Linux Mint 20 at its end of life, the time has arrived to upgrade to Linux Mint 22.