io_uring_buf_ring_add(3) — Linux manual page

io_uring_buf_ring_add(3)     liburing Manual    io_uring_buf_ring_add(3)

NAME

       io_uring_buf_ring_add - add buffers to a shared buffer ring

SYNOPSIS

       #include <liburing.h>

       void io_uring_buf_ring_add(struct io_uring_buf_ring *br,
                                  void *addr,
                                  unsigned int len,
                                  unsigned short bid,
                                  int mask,
                                  int buf_offset);

DESCRIPTION

       The io_uring_buf_ring_add(3) adds a new buffer to the shared
       buffer ring br.  The buffer address is indicated by addr and is
       of len bytes of length.  bid is the buffer ID, which will be
       returned in the CQE.  mask is the size mask of the ring,
       available from io_uring_buf_ring_mask(3).  buf_offset is the
       offset to insert at from the current tail. If just one buffer is
       provided before the ring tail is committed with
       io_uring_buf_ring_advance(3) or io_uring_buf_ring_cq_advance(3),
       then buf_offset should be 0. If buffers are provided in a loop
       before being committed, the buf_offset must be incremented by one
       for each buffer added.

RETURN VALUE

       None

NOTES

       liburing (or the kernel, for that matter) doesn't care about what
       buffer ID maps to what buffer, and in fact when recycling buffers
       after use, the application is free to add a different buffer into
       the same buffer ID location. All that matters is that the
       application knows what a given buffer ID in time corresponds to
       in terms of virtual memory. There's no liburing or kernel
       assumption that these mappings are persistent over time, they can
       very well be different every time a given buffer ID is added to
       the provided buffer ring.

SEE ALSO

       io_uring_register_buf_ring(3), io_uring_buf_ring_mask(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-2.2                  May 18, 2022      io_uring_buf_ring_add(3)

Pages that refer to this page: io_uring_buf_ring_add(3), io_uring_buf_ring_advance(3), io_uring_buf_ring_available(3), io_uring_buf_ring_cq_advance(3), __io_uring_buf_ring_cq_advance(3), io_uring_buf_ring_init(3), io_uring_buf_ring_mask(3), io_uring_prep_read_multishot(3), io_uring_prep_recv(3), io_uring_prep_recvmsg(3), io_uring_prep_recvmsg_multishot(3), io_uring_prep_recv_multishot(3), io_uring_prep_send(3), io_uring_prep_send_bundle(3), io_uring_prep_sendmsg(3), io_uring_prep_sendmsg_zc(3), io_uring_prep_sendto(3), io_uring_register_buf_ring(3), io_uring_setup_buf_ring(3)

---