io_uring_register_iowq_aff(3)	 liburing Manual   io_uring_register_iowq_aff(3)

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. Ex-
     isting workers may need to hit a schedule point before they are migrated.

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

     Applications  must	 define	 _GNU_SOURCE  to  obtain  the definition of this
     helper, as cpu_set_t will not be defined without it.


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)

liburing-2.2			 March 13, 2022	   io_uring_register_iowq_aff(3)