io_uring_setup_buf_ring(3) — Linux manual page

io_uring_setup_buf_ring(3)   liburing Manual  io_uring_setup_buf_ring(3)

NAME

       io_uring_setup_buf_ring - setup and register buffer ring for
       provided buffers

SYNOPSIS

       #include <liburing.h>

       struct io_uring_buf_ring *io_uring_setup_buf_ring(struct io_uring *ring,
                                   unsigned int nentries,
                                   int bgid,
                                   unsigned int flags,
                                   int *ret);

DESCRIPTION

       The io_uring_setup_buf_ring(3) function registers a shared buffer
       ring to be used with provided buffers. For the request types that
       support it, provided buffers are given to the ring and one is
       selected by a request if it has IOSQE_BUFFER_SELECT set in the
       SQE flags, when the request is ready to receive data. This allows
       both clear ownership of the buffer lifetime, and a way to have
       more read/receive type of operations in flight than buffers
       available.

       The ring argument must pointer to the ring for which the provided
       buffer ring is being registered, nentries is the number of
       entries requested in the buffer ring. This argument must be a
       power-of 2 in size.  bgid is the chosen buffer group ID, flags
       are modifier flags for the operation, and *ret is is a pointer to
       an integer for the error value if any part of the ring allocation
       and registration fails.

       The flags argument is currently unused and must be set to zero.

       Under the covers, this function uses
       io_uring_register_buf_ring(3) to register the ring, and handles
       the allocation of the ring rather than letting the application
       open code it.

       To unregister and free a buffer group ID setup with this
       function, the application must call io_uring_free_buf_ring(3).

       Available since 5.19.

RETURN VALUE

       On success io_uring_setup_buf_ring(3) returns a pointer to the
       buffer ring. On failure it returns NULL and sets *ret to -errno.

NOTES

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

SEE ALSO

       io_uring_register_buf_ring(3), io_uring_buf_ring_init(3),
       io_uring_buf_ring_add(3), io_uring_buf_ring_advance(3),
       io_uring_buf_ring_cq_advance(3)

COLOPHON

       This page is part of the liburing (A library for io_uring)
       project.  Information about the project can be found at 
       ⟨https://github.com/axboe/liburing⟩.  If you have a bug report for
       this manual page, send it to io-uring@vger.kernel.org.  This page
       was obtained from the project's upstream Git repository
       ⟨https://github.com/axboe/liburing⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-06-03.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

liburing-2.4                  Mar 07, 2023    io_uring_setup_buf_ring(3)

Pages that refer to this page: io_uring_buf_ring_init(3), io_uring_free_buf_ring(3), io_uring_register_buf_ring(3), io_uring_setup_buf_ring(3)

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