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 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