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 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/sysmacros.h>
33 #include <sys/systm.h>
34 #include <sys/errno.h>
35 #include <sys/cred.h>
36 #include <sys/proc.h>
37 #include <sys/debug.h>
38 #include <sys/class.h>
39 #include <sys/mutex.h>
40 #include <sys/schedctl.h>
41
42 /*
43 * We support the nice system call for compatibility although
44 * the priocntl system call supports a superset of nice's functionality.
45 * We support nice only for time sharing threads. It will fail
46 * if called by a thread from another class.
47 */
48
49 int
nice(int niceness)50 nice(int niceness)
51 {
52 int error = 0;
53 int err, retval;
54 kthread_t *t;
55 proc_t *p = curproc;
56
57 mutex_enter(&p->p_lock);
58 t = p->p_tlist;
59 do {
60 err = CL_DONICE(t, CRED(), niceness, &retval);
61 schedctl_set_cidpri(t);
62 if (error == 0 && err)
63 error = set_errno(err);
64 } while ((t = t->t_forw) != p->p_tlist);
65 mutex_exit(&p->p_lock);
66 if (error)
67 return (error);
68 return (retval);
69 }
70