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Improve buffers documentation #1526

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6 changes: 6 additions & 0 deletions man/io_uring_register_buffers.3
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Original file line number Diff line number Diff line change
Expand Up @@ -95,6 +95,12 @@ return 0.
return number of buffers updated.
On failure they return
.BR -errno .

.SH NOTES
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@axboe axboe Jan 15, 2026

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I'd word this stronger - "Don't use this API for new code. Use the more efficient io_uring_register_buf_ring(3) API instead, see that man page for details."

When possible prefer to use the newer and more efficient
.BR io_uring_register_buf_ring (3)
API.

.SH SEE ALSO
.BR io_uring_register (2),
.BR io_uring_get_sqe (3),
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6 changes: 6 additions & 0 deletions man/io_uring_setup_buf_ring.3
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Expand Up @@ -80,12 +80,18 @@ returns a pointer to the buffer ring. On failure it returns
and sets
.I *err
to -errno.

.SH NOTES
Note that even if the kernel supports this feature, registering a provided
buffer ring may still fail with
.B -EINVAL
if the host is a 32-bit architecture and the memory being passed in resides in
high memory.

Remember that you need to call
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@axboe axboe Jan 15, 2026

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"Use io_uring_buf_ring_add(3) to add buffers to the ring, and io_uring_buf_ring_advance(3) to make these buffers available to the kernel. Refer to those man pages for details."

.BR io_uring_buf_ring_add (3)
to make the allocated buffers available to the kernel.

.SH SEE ALSO
.BR io_uring_register_buf_ring (3),
.BR io_uring_buf_ring_init (3),
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