NAME

       io_uring_register_iowq_aff - register async worker CPU affinities

SYNOPSIS

       #include <sched.h>
       #include <liburing.h>

       int io_uring_register_iowq_aff(struct io_uring *ring,
                                      size_t cpusz,
                                      const cpu_set_t *mask);

       void io_uring_unregister_iowq_aff(struct io_uring *ring);

DESCRIPTION

       The  io_uring_prep_register_iowq_aff(3)  function  registers a set of CPU affinities to be
       used by the io_uring async workers. By default, io_uring async workers are allowed to  run
       on any CPU in the system. If this function is called with ring set to the ring in question
       and mask set to a pointer to a cpu_set_t value and cpusz set to the size of the  CPU  set,
       then async workers will only be allowed to run on the CPUs specified in the mask. Existing
       workers may need to hit a schedule point before they are migrated.

       For  unregistration,  io_uring_unregister_iowq_aff(3)  may  be  called  to   restore   CPU
       affinities to the default.

RETURN VALUE

       Returns 0 on success, or any of the following values in case of error.

       -EFAULT
              The kernel was unable to copy the memory pointer to by mask as it was invalid.

       -ENOMEM
              The kernel was unable to allocate memory for the new CPU mask.

       -EINVAL
              cpusz or mask was NULL/0, or any other value specified was invalid.

SEE ALSO

       io_uring_queue_init(3), io_uring_register(2)