"idle priority" support. Based on code from Henrik Vestergaard Draboel,

but substantially rewritten by me.

4 files changed, 258 insertions, 115 deletions

diff --git a/usr.sbin/rtprio/Makefile b/usr.sbin/rtprio/Makefile
index 2ca8da9..af159bf 100644
--- a/usr.sbin/rtprio/Makefile
+++ b/usr.sbin/rtprio/Makefile
@@ -1,7 +1,11 @@
 #	from: @(#)Makefile	5.5 (Berkeley) 5/11/90
-#	$Id: Makefile,v 1.2 1993/11/23 00:02:21 jtc Exp $
+#	$Id: Makefile,v 1.1 1994/09/01 12:05:12 davidg Exp $
 
 BINDIR=/usr/sbin
 PROG=	rtprio
+LINKS=  ${BINDIR}/rtprio ${BINDIR}/idprio
+MLINKS= rtprio.1 idprio.1
+MAN1=	rtprio.1
+MAN2=	rtprio.2
 
 .include <bsd.prog.mk>
diff --git a/usr.sbin/rtprio/rtprio.1 b/usr.sbin/rtprio/rtprio.1
index a2cc7dc..5542f12 100644
--- a/usr.sbin/rtprio/rtprio.1
+++ b/usr.sbin/rtprio/rtprio.1
@@ -34,35 +34,50 @@
 .Dt RTPRIO 1
 .Os 
 .Sh NAME
-.Nm rtprio
-.Nd execute, examine or modify a process's realtime scheduling priority
+.Nm rtprio ,
+.Nm idprio
+.Nd execute, examine or modify a utilitys or process realtime 
+or idletime scheduling priority
 .Sh SYNOPSIS
 
-.Nm rtprio
-.Nm rtprio 
+.Nm [id|rt]prio
+.Nm [id|rt]prio 
 .Ar pid
-.Nm rtprio 
+.Nm [id|rt]prio 
 .Ar priority
 .Ar command
 .Op args
-.Nm rtprio 
+.Nm [id|rt]prio 
 .Ar priority
 .Ar -pid
-.Nm rtprio 
+.Nm [id|rt]prio 
 .Ar -t
 .Ar command
 .Op args
-.Nm rtprio 
+.Nm [id|rt]prio 
 .Ar -t
 .Ar -pid
 .Sh DESCRIPTION
 .Nm Rtprio
-is used for controlling realtime process scheduling. A process with a
-realtime priority is not subject to priority degradation, and will only
-be preempted by another process of equal or higher realtime priority.
+is used for controlling realtime process scheduling. 
 
-.Nm Rtprio
-called without arguments, will return the realtime priority
+.Nm Idprio
+is used for controlling idletime process scheduling, and can be called
+with the same options as 
+.Nm Rtprio .
+
+A process with a realtime priority is not subject to priority
+degradation, and will only be preempted by another process of equal or
+higher realtime priority.
+
+A process with an idle priority will run only when no other
+process is runnable and then only if it's idle priority is equal or
+greater than all other runnable idle priority processes.
+
+.Nm Rtprio 
+or
+.Nm Idprio 
+when called without arguments will return the realtime priority
 of the current process.
 
 If
@@ -81,23 +96,27 @@ process.
 
 If
 .Ar -pid
-is specified, the process with that pid will be modified, else
-if 
+is specified, the process with the process identifier "pid" will be
+modified, else if
 .Ar command 
 is specified, that program is run with its arguments.
 
 .Ar Priority
-is an integer between 0 (RTPRIO_MIN) and 31 (RTPRIO_MAX). 0 is the
+is an integer between 0 and RTP_PRIO_MAX (usually 31). 0 is the
 highest priority
 
 .Ar Pid
 of 0 means "the current process".
 
-Only root is allowed to set realtime priorities.
+Only root is allowed to set realtime priorities. Non-root processes may
+set idle priority levels for the current process only.
 .Sh RETURN VALUE
+If
 .Nm rtprio
-returns the (new) realtime priority of the process (see rtprio(2)), or
--1 for all usage errors.
+execute a command, the exit value is that of the command executed.
+In all other cases,
+.Nm
+exits with 0 for success and 1 for all other errors.
 .Sh EXAMPLES
 .\LP
 
@@ -131,16 +150,17 @@ To run \fItcpdump\fP without realtime priority:
 .Ed
 
 .\.LP
-To change the realtime priority of process \fI1423\fP to RTRIO_RTOFF
-(no realtime):
+To change the realtime priority of process \fI1423\fP to RTP_PRIO_NORMAL
+(non-realtime/"normal" priority):
 .Bd -literal -offset indent -compact
 \fBrtprio -t -1423\fP
 .Ed
-.Sh DIAGNOSTICS
-The
-.Nm rtprio
-utility shall exit with value of the (new) realtime priority of the
-program.
+
+.\.LP
+To make depend while not disturbing other machine usage:
+.Bd -literal -offset indent -compact
+\fBidprio 31 make depend\fP
+.Ed
 .Sh SEE ALSO
 .Xr rtprio 2 ,
 .Xr nice 1 ,
@@ -153,13 +173,25 @@ The
 utility appeared in
 FreeBSD 2.0,
 but is similar to the HP-UX version.
+.Sh CAVEATS
+You can lock yourself out of the system by placing a cpu-heavy
+process in a realtime priority.
 .Sh BUGS
-You can lock yourself out of the system by placing a cpu-intensive
-process into realtime priority.
-
 There is no way to set/view the realtime priority of process 0
 (swapper) (see ps(1)).
 
+There is in
+FreeBSD
+no way to ensure that a process page is present in memory therefore
+the process may be stopped for pagein. (See mprotect(2), madvise(2)).
+
+Under
+FreeBSD
+system calls are currently never preempted, therefore non-realtime
+processes can starve realtime procesess, or idletime processes can
+starve normal priority processes.
+
 Others ...
 .Sh AUTHOR
-Henrik Vestergaard Draboel - hvd@terry.ping.dk
+Henrik Vestergaard Draboel - hvd@terry.ping.dk is the original author. This
+implementation in FreeBSD was substantially rewritten by David Greenman.
diff --git a/usr.sbin/rtprio/rtprio.2 b/usr.sbin/rtprio/rtprio.2
new file mode 100644
index 0000000..2c1b4c7
--- /dev/null
+++ b/usr.sbin/rtprio/rtprio.2
@@ -0,0 +1,106 @@
+.\" Copyright (c) 1994, Henrik Vestergaard Draboel
+.\" All rights reserved.
+.\" 
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\" 	This product includes software developed by Henrik Vestergaard Draboel.
+.\" 4. The name of the author may not be used to endorse or promote products
+.\"    derived from this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\" 
+.\" $Id: rtprio.2,v 1.2 1994/09/01 12:09:17 davidg Exp $
+.\"
+.Dd July 23, 1994
+.Dt RTPRIO 2
+.Sh NAME
+.Nm rtprio
+.Nd examine or modify a process realtime or idle priority
+.Sh SYNOPSIS
+.Fd #include <sys/resource.h>
+.Fd #include <sys/rtprio.h>
+.Ft int 
+.Fn rtprio "function" "pid_t pid" "struct rtprio *rtp"
+.Sh DESCRIPTION
+.Fn rtprio
+is used to lookup or change the realtime or idle priority of a process.
+
+.Fa function
+specifies the operation to be performed. RTP_LOOKUP to lookup the current priority, 
+and RTP_SET to set the priority.
+.Fa pid
+specifies the process to be used, 0 for the current process.
+
+.Fa *rtp
+is a pointer to a struct rtprio which is used to specify the priority and priority type. 
+This structure has the following form:
+.Bd -literal
+struct rtprio {
+	u_short	type;
+	u_short prio;
+};
+.Ed
+.Pp
+The value of the
+.Nm 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
+.Nm prio
+field ranges between 0 and  
+.Dv RTP_PRIO_MAX (usually 31) .
+0 is the highest possible priority.
+
+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.
+.Sh RETURN VALUES
+.Fn rtprio
+will return 0 for success and -1 for all errors. The global variable
+.Va errno
+will be set to indicate the error.
+.Sh ERRORS
+.Fn rtprio
+will fail if 
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The specified
+.Fa prio
+was out of range.
+.It Bq Er 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.
+.It Bq Er ESRCH
+The specified process was not found.
+.Sh AUTHOR
+The original author was Henrik Vestergaard Draboel - hvd@terry.ping.dk. This
+implementation in FreeBSD was substantially rewritten by David Greenman.
+.Sh SEE ALSO
+.Xr rtprio 1 ,
+.Xr nice 1 ,
+.Xr ps 1 ,
+.Xr nice 2 ,
+.Xr renice 8
+
diff --git a/usr.sbin/rtprio/rtprio.c b/usr.sbin/rtprio/rtprio.c
index cc66fd4..ab4d085 100644
--- a/usr.sbin/rtprio/rtprio.c
+++ b/usr.sbin/rtprio/rtprio.c
@@ -1,5 +1,6 @@
 /*
- * Copyright (c) 1994 The Regents of the University of California.
+ * Copyright (c) 1994 David Greenman
+ * Copyright (c) 1994 Henrik Vestergaard Draboel (hvd@terry.ping.dk)
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -12,16 +13,16 @@
  *    documentation and/or other materials provided with the distribution.
  * 3. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
- *	This product includes software developed by the University of
- *	California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
+ *	This product includes software developed by Henrik Vestergaard Draboel.
+ *	This product includes software developed by David Greenman.
+ * 4. Neither the names of the authors nor the names of contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
@@ -29,28 +30,15 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
+ *
+ *	$Id$
  */
 
-/* Copyright (c) 1994 Henrik Vestergaard Drabøl (hvd@terry.pping.dk) */
-
-#ifndef lint
-char copyright[] =
-"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
- All rights reserved.\n";
-#endif /* not lint */
-
-#ifndef lint
-/*static char sccsid[] = "from: @(#)rtprio.c	5.4 (Berkeley) 6/1/90";*/
-static char rcsid[] = "$Id: rtprio.c,v 1.2 1993/11/23 00:02:23 jtc Exp $";
-#endif /* not lint */
-
-#include <sys/time.h>
-#include <stdio.h>
+#include <sys/param.h>
 #include <sys/rtprio.h>
-#include <locale.h>
-#include <errno.h>
-#include <err.h>
+#include <sys/errno.h>
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
@@ -60,82 +48,95 @@ static void usage();
 
 int
 main(argc, argv)
-	int argc;
-	char **argv;
+	int     argc;
+	char  **argv;
 {
-	int nrtprio = RTPRIO_RTOFF;
-	int proc=0;
+	char   *p;
+	int     proc = 0;
+	struct rtprio rtp;
+
+	/* find basename */
+	if ((p = rindex(argv[0], '/')) == NULL)
+		p = argv[0];
+	else
+		++p;
 
-	setlocale(LC_ALL, "");
-	errno = 0;
+	if (!strcmp(p, "rtprio"))
+		rtp.type = RTP_PRIO_REALTIME;
+	else if (!strcmp(p, "idprio"))
+		rtp.type = RTP_PRIO_IDLE;
 
 	switch (argc) {
-        case 2:
-	  proc = abs(atoi(argv[1]));
+	case 2:
+		proc = abs(atoi(argv[1]));	/* Should check if numeric
+						 * arg! */
 		/* FALLTHROUGH */
-
 	case 1:
-          nrtprio = rtprio(proc,RTPRIO_NOCHG);
-          fprintf(stderr,"rtprio: %d %s\n",
-            nrtprio,
-            nrtprio==RTPRIO_RTOFF?"(RTOFF)":"");
-          exit(nrtprio); 
-		/* NOTREACHED */
-          
-        default: {
-		switch (argv[1][0]) {
-		case '-':
-		  if (strcmp(argv[1],"-t")==0)
-		       nrtprio = RTPRIO_RTOFF;
-		     else 
-		       usage();
-  		  break;
-
-		case '0':case '1':case '2':case '3':case '4':
-		case '5':case '6':case '7':case '8':case '9':
-		  nrtprio = atoi (argv[1]);
-
-		  if (errno== ERANGE) usage();
-		  break;
-
+		if (rtprio(RTP_LOOKUP, proc, &rtp) != 0) {
+			perror(argv[0]);
+			exit (1);
+		}
+		printf("%s: ", p);
+		switch (rtp.type) {
+		case RTP_PRIO_REALTIME:
+			printf("realtime priority %d\n", rtp.prio);
+			break;
+		case RTP_PRIO_NORMAL:
+			printf("normal priority\n");
+			break;
+		case RTP_PRIO_IDLE:
+			printf("idle priority %d\n", rtp.prio);
+			break;
 		default:
-		  usage(); 
-		  break;
+			printf("invalid priority type %d\n", rtp.type);
+			break;
 		}
-		switch (argv[2][0]) {
-		case '-':
-		  proc = -atoi(argv[2]);
-
-  		break;
+		exit(0);
+	default:
+		if (argv[1][0] == '-' || isdigit(argv[1][0])) {
+			if (argv[1][0] == '-') {
+				if (strcmp(argv[1], "-t") == 0) {
+					rtp.type = RTP_PRIO_NORMAL;
+					rtp.prio = 0;
+				} else {
+					usage(p);
+					break;
+				}
+			} else {
+				rtp.prio = atoi(argv[1]);
+			}
+		} else {
+			usage(p);
+			break;
 		}
-      
-	errno = 0;
 
-        nrtprio = rtprio(proc, nrtprio);
+		if (argv[2][0] == '-')
+			proc = -atoi(argv[2]);
 
-	if (errno) {
-		err (1, "rtprio");
-		/* NOTREACHED */
-	}
+		if (rtprio(RTP_SET, proc, &rtp) != 0) {
+			perror(argv[0]);
+			exit (1);
+		}
 
-	if (proc == 0) {
-          execvp(argv[2], &argv[2]);
-   	  err ((errno == ENOENT) ? 127 : 126, "%s", argv[2]);}
-	  /* NOTREACHED */
-	      }
+		if (proc == 0) {
+			execvp(argv[2], &argv[2]);
+			perror(argv[0]);
+			exit (1);
+		}
 	}
-return(nrtprio);
+	exit (1);
 }
 
 static void
-usage()
+usage(basename)
+	char   *basename;
 {
-	(void)fprintf(stderr, "usage: rtprio\n");
-	(void)fprintf(stderr, "usage: rtprio [-] pid\n");
-	(void)fprintf(stderr, "usage: rtprio priority command [ args ] \n");
-	(void)fprintf(stderr, "usage: rtprio priority -pid \n");
-	(void)fprintf(stderr, "usage: rtprio -t command [ args ] \n");
-	(void)fprintf(stderr, "usage: rtprio -t -pid \n");
-	
+	(void) fprintf(stderr, "usage: %s\n", basename);
+	(void) fprintf(stderr, "usage: %s [-]pid\n", basename);
+	(void) fprintf(stderr, "usage: %s priority command [ args ] \n", basename);
+	(void) fprintf(stderr, "usage: %s priority -pid \n", basename);
+	(void) fprintf(stderr, "usage: %s -t command [ args ] \n", basename);
+	(void) fprintf(stderr, "usage: %s -t -pid \n", basename);
+
 	exit(-1);
 }