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 rtsched(1)							  rtsched(1)




 NAME
      rtsched - execute process with real-time priority

 SYNOPSIS
      rtsched -s scheduler -p priority command [arguments]

      rtsched [ -s scheduler ] -p priority -P pid

 DESCRIPTION
      Rtsched executes command with POSIX or HP-UX real-time priority, or
      changes the real-time priority of currently executing process pid.

      All POSIX real-time priority processes are of greater scheduling
      importance than processes with HP-UX real-time or HP-UX timeshare
      priority.	 All HP-UX real-time priority processes are of greater
      scheduling importance than HP-UX timeshare priority processes, but are
      of lesser importance than POSIX real-time processes.  Neither POSIX
      nor HP-UX real-time processes are subject to degradation.	 POSIX
      real-time processes may be scheduled with one of three different POSIX
      real-time schedulers: SCHED_FIFO, SCHED_RR, or SCHED_RR2.	 See
      rtsched(2) for details.

      Rtsched is a superset of rtprio. See rtprio(1).

    Options
      -s scheduler   Specify the desired scheduler:
			   POSIX real-time schedulers:	 SCHED_FIFO
							 SCHED_RR
							 SCHED_RR2

			   HP-UX real-time scheduler:	 SCHED_RTPRIO

			   HP-UX timeshare scheduler:	 SCHED_HPUX
							 SCHED_NOAGE

      -p priority    Specify priority range; any integer within the
		     inclusive priority range of the corresponding
		     scheduler.	 -p priority is required for all schedulers
		     except SCHED_HPUX.	 If scheduler is SCHED_HPUX, the
		     priority argument is ignored.  The default priority
		     range of each scheduler is as follows:


			scheduler      highest priority	  lowest priority
			_________________________________________________
			SCHED_FIFO		     31			0
			SCHED_RR		     31			0
			SCHED_RR2		     31			0
			SCHED_RTPRIO		      0		      127
			SCHED_NOAGE		    178		      255
			SCHED_HPUX		    N/A		      N/A



 Hewlett-Packard Company	    - 1 -   HP-UX Release 11i: November 2000






 rtsched(1)							  rtsched(1)




		     Note: Higher numerical values for the priority
		     represent higher priorities under POSIX real-time
		     schedulers, whereas lower numerical values for the
		     priority represent higher priorities under HP-UX real-
		     time and timeshare schedulers.

      -P	     Specify an already executing process ID (pid).

      Command is not scheduled, or pid's real-time priority is not changed,
      if the user is not a member of a group having PRIV_RTSCHED access and
      is not the user with appropriate privileges.  When changing the real-
      time priority of a currently executing process, the effective 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
      rtsched returns exit status:

	   0	   if command is successfully scheduled or if pid's real-
		   time priority is successfully changed;

	   1	   if command is not executable, pid does not exist, or
		   priority is not within the priority range for the
		   corresponding scheduler;

	   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; or

	   5	   if rtsched encountered an internal error or if rtsched is
		   not supported by this release.

 EXAMPLES
      Execute file a.out with SCHED_FIFO at a priority of 10:

	   rtsched -s SCHED_FIFO -p 10 a.out

      Execute file a.out with SCHED_RTPRIO at a priority of 127 (this is
      synonymous to rtprio 127 a.out):

	   rtsched -s SCHED_RTPRIO -p 127 a.out

      Execute file a.out with the SCHED_HPUX scheduler:

	   rtsched -s SCHED_HPUX a.out

      This is useful to spawn a timeshare priority command from a real-time
      priority shell.



 Hewlett-Packard Company	    - 2 -   HP-UX Release 11i: November 2000






 rtsched(1)							  rtsched(1)




      Set the currently running process pid 24217 to execute with SCHED_RR2
      at a priority of 20:

	   rtsched -s SCHED_RR2 -p 20 -P 24217

      Now change its priority to 10 using the same scheduler:

	   rtsched -p 10 -P 24217

 WARNINGS
      Priority values used by rtsched may differ from those used by other
      commands.	 For example, ps(1) displays the internal representation of
      priority values.

 AUTHOR
      rtsched was developed by HP.

 SEE ALSO
      rtprio(1), setprivgrp(1M), getprivgrp(2), rtprio(2), rtsched(2).



































 Hewlett-Packard Company	    - 3 -   HP-UX Release 11i: November 2000