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 51 int 52 nice(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