Linux

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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

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The Linux kernel has been accidentally hardcoded to a maximum of 8 cores for the past 15 years and nobody noticed (thehftguy.com)

submitted 11 months ago by [email protected] to c/[email protected]

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"The min_granularity setting was renamed to base_slice in this commit in v6 kernel.

The comment says it scales with CPU count and the comment is incorrect. I wonder whether kernel developers are aware of that mistake as they are rewriting the scheduler!

Official comments in the code says it’s scaling with log2(1+cores) but it doesn’t.
All the comments in the code are incorrect.
Official documentation and man pages are incorrect.
Every blog article, stack overflow answer and guide ever published about the scheduler is incorrect."

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[–] [email protected] 19 points 11 months ago (1 children)

Isn't there quite some information missing? Which scheduler is affected? What are the are the exact consequences since we're talking about latency in the first part of the article. Did it affect the AMD Epyc processors that run all the VPS?

[–] [email protected] 7 points 11 months ago* (last edited 11 months ago)

Nothing is affected. The headline is largely bullshit. A minor optimization for high core-count systems did not go as far as originally planned, and that may or may not have made a barely noticable difference.