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A comment on Io_uring and Networking in 2023 [pdf]. Parent comment

Re:Io_uring and Networking in 2023 [pdf] by WJW on Friday February 17, 2023 @08:58AM (#34834687)
The "u" in "uring" has nothing to do with its size but rather with it being a "userspace ring". The ring buffers used by this particular API reside in userspace rather than in kernel memory.
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Re:Io_uring and Networking in 2023 [pdf] by loeg on Friday February 17, 2023 @11:09AM (#34836373)
> The ring buffers used by this particular API reside in userspace rather than in kernel memory.

More specifically, the physical pages backing these ring buffers are pinned and mapped into both address spaces. (The kernel needs to be able to read submissions (sqes) off of it and write completions (cqes) into it, and could not do that if it were only mapped in userspace, or could be paged out.)

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Re:Io_uring and Networking in 2023 [pdf] by axboe on Friday February 17, 2023 @04:28PM (#34840800)
This is correct, the "u" is for userspace/usermapped. The memory is actually allocate by the kernel, but it's mapped into the applications address space.
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