rtprio(1) [hpux man page]

rtprio(1)						      General Commands Manual							 rtprio(1)

NAME

       rtprio - execute process with real-time priority

SYNOPSIS

       priority command [arguments]

       priority

       command [arguments]

DESCRIPTION

       executes  command  with	a  real-time priority, or changes the real-time priority of currently executing process pid.  Real-time priorities
       range from zero (highest) to 127 (lowest).  Real-time processes are not subject to priority degradation, and are all of	greater  (schedul-
       ing) importance than non-real-time processes.  See rtprio(2) for more details.

       If  is specified instead of a real-time priority, executes command with a timeshare (non-real-time) priority, or changes the currently exe-
       cuting process pid from a possibly real-time priority to a timeshare priority.  The former is useful to spawn a timeshare priority  command
       from a real-time priority shell.

       If  is  not  specified, command is not scheduled, or pid's real-time priority is not changed, if the user is not a member of a group having
       access and is not the user with appropriate privileges.	When changing the real-time priority of a currently executing process, the  effec-
       tive  user  ID of the calling process must be the user with appropriate privileges, or the real or effective user ID must match the real or
       saved user ID of the process to be modified.

RETURN VALUE

       returns exit status 0 if command is successfully scheduled or if pid's real-time priority is successfully changed, 1 if command is not exe-
       cutable	or pid does not exist, and 2 if command (pid) lacks real-time capability, or the invoker's effective user ID is not a user who has
       appropriate privileges, or the real or effective user or the real or effective user ID does not match the real or  saved  user  ID  of  the
       process being changed.

EXAMPLES

       Execute file at a real-time priority of 100:

       Set the currently running process pid 24217 to a real-time priority of 40:

AUTHOR

       was developed by HP.

SEE ALSO

       setprivgrp(1M), getprivgrp(2), rtprio(2).

																	 rtprio(1)

RTPRIO(2)						      BSD System Calls Manual							 RTPRIO(2)

NAME

     rtprio -- examine or modify a process realtime or idle priority

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/types.h>
     #include <sys/rtprio.h>

     int
     rtprio(int function, pid_t pid, struct rtprio *rtp);

DESCRIPTION

     The rtprio() system call is used to lookup or change the realtime or idle priority of a process.

     The function argument specifies the operation to be performed.  RTP_LOOKUP to lookup the current priority, and RTP_SET to set the priority.
     The pid argument specifies the process to be used, 0 for the current process.

     The *rtp argument is a pointer to a struct rtprio which is used to specify the priority and priority type.  This structure has the following
     form:

     struct rtprio {
	     u_short type;
	     u_short prio;
     };

     The value of the type field may be RTP_PRIO_REALTIME for realtime priorities, RTP_PRIO_NORMAL for normal priorities, and RTP_PRIO_IDLE for
     idle priorities.  The priority specified by the prio field ranges between 0 and RTP_PRIO_MAX (usually 31).  0 is the highest possible prior-
     ity.

     Realtime and idle priority is inherited through fork() and exec().

     A realtime process can only be preempted by a process of equal or higher priority, or by an interrupt; idle priority processes will run only
     when no other real/normal priority process is runnable.  Higher real/idle priority processes preempt lower real/idle priority processes.
     Processes of equal real/idle priority are run round-robin.

RETURN VALUES

     The rtprio() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate
     the error.

ERRORS

     The rtprio() system call will fail if

     [EINVAL]		The specified prio was out of range.

     [EPERM]		The calling process is not allowed to set the realtime priority.  Only root is allowed to change the realtime priority of
			any process, and non-root may only change the idle priority of the current process.

     [ESRCH]		The specified process was not found.

SEE ALSO

     nice(1), ps(1), rtprio(1), setpriority(2), nice(3), renice(8)

AUTHORS

     The original author was Henrik Vestergaard Draboel <hvd@terry.ping.dk>.  This implementation in FreeBSD was substantially rewritten by David
     Greenman.

BSD
								   July 23, 1994							       BSD