2 * Copyright (c) 2005 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Sergey Glushchenko <deen@smz.com.ua>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * $DragonFly: src/sys/kern/kern_usched.c,v 1.2 2006/03/23 14:04:24 drhodus Exp $
37 #include <sys/errno.h>
38 #include <sys/globaldata.h> /* curthread */
40 #include <sys/sysproto.h> /* struct usched_set_args */
41 #include <sys/systm.h> /* strcmp() */
42 #include <sys/usched.h>
44 static TAILQ_HEAD(, usched) usched_list = TAILQ_HEAD_INITIALIZER(usched_list);
47 * Called from very low level boot code, i386/i386/machdep.c/init386().
48 * We cannot do anything fancy. no malloc's, no nothing other then
49 * static initialization.
55 * Add the bsd4 userland scheduler to the system.
57 usched_ctl(&usched_bsd4, USCH_ADD);
65 * Add/remove usched to/from list.
68 * usched - pointer to target scheduler
69 * action - addition or removal ?
76 usched_ctl(struct usched *usched, int action)
78 struct usched *item; /* temporaly for TAILQ processing */
84 * Make sure it isn't already on the list
87 TAILQ_FOREACH(item, &usched_list, entry) {
88 KKASSERT(item != usched);
92 * Optional callback to the scheduler before we officially
95 if (usched->usched_register)
96 usched->usched_register();
97 TAILQ_INSERT_TAIL(&usched_list, usched, entry);
101 * Do not allow the default scheduler to be removed
103 if (strcmp(usched->name, "bsd4") == 0) {
107 TAILQ_FOREACH(item, &usched_list, entry) {
112 if (item->usched_unregister)
113 item->usched_unregister();
114 TAILQ_REMOVE(&usched_list, item, entry);
127 * USCHED_SET(syscall)
130 * Setting up a proc's usched.
133 * name - usched's name
140 usched_set(struct usched_set_args *uap)
142 struct proc *p = curthread->td_proc;
143 struct usched *item; /* temporaly for TAILQ processing */
145 char buffer[NAME_LENGTH];
147 if ((error = suser(curthread)) != 0)
150 if ((error = copyinstr(uap->name, buffer, sizeof(buffer), NULL)) != 0)
153 TAILQ_FOREACH(item, &usched_list, entry) {
154 if ((strcmp(item->name, buffer) == 0))
159 * If the scheduler for a process is being changed, disassociate
160 * the old scheduler before switching to the new one.
162 * XXX we might have to add an additional ABI call to do a 'full
163 * disassociation' and another ABI call to do a 'full reassociation'
165 if (item && item != p->p_usched) {
166 p->p_usched->release_curproc(&p->p_lwp);
168 } else if (item == NULL) {