IOPRIO_GET(2)

NAME
ioprio_get, ioprio_set - get/set the I/O priority

LIBRARY
libc

SYNOPSIS
#include <sys/resource.h>
int
ioprio_get(int which, int who);
int
ioprio_set(int which, int who, int prio);

DESCRIPTION
The ioprio_get() and ioprio_set() functions get and set the I/O scheduler priority of a process, process group or all processes of a user.

The which argument specifies what type of resource's priority is to be modified. It can have the following values (as defined in <sys/resource.h>):

PRIO_PROCESS
    A single process

PRIO_PGRP
    A process group

PRIO_USER
    All processes of a user

The who argument specifies, depending on the which argument, either the process ID (if which is PRIO_PROCESS), the process group ID (if which is PRIO_PGRP), or the user ID (if which is PRIO_USER). A value of 0 specifies either the current process, the current process group, or the current user.

For the ioprio_set() function, the prio argument specifies the priority to be set. It can range from 1 to 10, with higher numbers indicating a higher priority.

RETURN VALUES

ERRORS
The ioprio_get() function will fail if:

[EINVAL]
    An invalid value was specified for the which argument

[ESRCH]
    No corresponding process, process group or user could be found for the ID specified in who

The ioprio_set() function will fail if:

[EACCES]
    The caller isn't allowed to access the I/O priority

[EINVAL]
    An invalid value was specified for the which argument

[EPERM]
    The caller doesn't own the specified process or processes

[ESRCH]
    No corresponding process, process group or user could be found for the ID specified in who

SEE ALSO
ioprio(1)

HISTORY
The ioprio_get() and ioprio_set() function calls first appeared in DragonFly 2.7.

AUTHORS
-nosplit Alex Hornung