| io_uring_register_buffers(3) | liburing Manual | io_uring_register_buffers(3) |
io_uring_register_buffers - register buffers for fixed buffer operations
#include <liburing.h>
int io_uring_register_buffers(struct io_uring *ring,
const struct iovec *iovecs,
unsigned nr_iovecs);
int io_uring_register_buffers_sparse(struct io_uring *ring,
unsigned nr_iovecs);
The io_uring_register_buffers(3) function registers nr_iovecs number of buffers defined by the array iovecs belonging to the ring.
The io_uring_register_buffers_sparse(3) function registers nr_iovecs empty buffers belonging to the ring. These buffers must be updated before use, using eg io_uring_register_buffers_update_tag(3).
After the caller has registered the buffers, they can be used with one of the fixed buffers functions.
Registered buffers is an optimization that is useful in conjunction with O_DIRECT reads and writes, where it maps the specified range into the kernel once when the buffer is registered rather than doing a map and unmap for each IO every time IO is performed to that region. Additionally, it also avoids manipulating the page reference counts for each IO.
On success io_uring_register_buffers(3) and io_uring_register_buffers_sparse(3) return 0. On failure they return -errno.
io_uring_get_sqe(3), io_uring_unregister_buffers(3), io_uring_register_buf_ring(3), io_uring_prep_read_fixed(3), io_uring_prep_write_fixed(3)
| November 15, 2021 | liburing-2.1 |