1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28/*	  All Rights Reserved  	*/
29
30#pragma ident	"%Z%%M%	%I%	%E% SMI"	/* from SVr4.0 1.15 */
31
32#include <sys/types.h>
33#include <sys/param.h>
34#include <sys/sysmacros.h>
35#include <sys/systm.h>
36#include <sys/errno.h>
37#include <sys/cred.h>
38#include <sys/proc.h>
39#include <sys/debug.h>
40#include <sys/class.h>
41#include <sys/mutex.h>
42#include <sys/schedctl.h>
43
44/*
45 * We support the nice system call for compatibility although
46 * the priocntl system call supports a superset of nice's functionality.
47 * We support nice only for time sharing threads.  It will fail
48 * if called by a thread from another class.
49 */
50
51int
52nice(int niceness)
53{
54	int error = 0;
55	int err, retval;
56	kthread_t *t;
57	proc_t *p = curproc;
58
59	mutex_enter(&p->p_lock);
60	t = p->p_tlist;
61	do {
62		err = CL_DONICE(t, CRED(), niceness, &retval);
63		schedctl_set_cidpri(t);
64		if (error == 0 && err)
65			error = set_errno(err);
66	} while ((t = t->t_forw) != p->p_tlist);
67	mutex_exit(&p->p_lock);
68	if (error)
69		return (error);
70	return (retval);
71}
72