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;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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 1.9 2007/07/02 17:06:55 dillon Exp $
37 #include <sys/errno.h>
38 #include <sys/globaldata.h> /* curthread */
41 #include <sys/sysproto.h> /* struct usched_set_args */
42 #include <sys/systm.h> /* strcmp() */
43 #include <sys/usched.h>
44 #include <machine/smp.h>
46 static TAILQ_HEAD(, usched) usched_list = TAILQ_HEAD_INITIALIZER(usched_list);
48 cpumask_t usched_mastermask = -1;
51 * Called from very low level boot code, i386/i386/machdep.c/init386().
52 * We cannot do anything fancy. no malloc's, no nothing other then
53 * static initialization.
60 defsched = kgetenv("kern.user_scheduler");
63 * Add various userland schedulers to the system.
65 usched_ctl(&usched_bsd4, USCH_ADD);
66 usched_ctl(&usched_dummy, USCH_ADD);
67 if (defsched == NULL )
69 if (strcmp(defsched, "bsd4") == 0)
71 kprintf("WARNING: Running dummy userland scheduler\n");
72 return(&usched_dummy);
79 * Add/remove usched to/from list.
82 * usched - pointer to target scheduler
83 * action - addition or removal ?
90 usched_ctl(struct usched *usched, int action)
92 struct usched *item; /* temporaly for TAILQ processing */
98 * Make sure it isn't already on the list
101 TAILQ_FOREACH(item, &usched_list, entry) {
102 KKASSERT(item != usched);
106 * Optional callback to the scheduler before we officially
107 * add it to the list.
109 if (usched->usched_register)
110 usched->usched_register();
111 TAILQ_INSERT_TAIL(&usched_list, usched, entry);
115 * Do not allow the default scheduler to be removed
117 if (strcmp(usched->name, "bsd4") == 0) {
121 TAILQ_FOREACH(item, &usched_list, entry) {
126 if (item->usched_unregister)
127 item->usched_unregister();
128 TAILQ_REMOVE(&usched_list, item, entry);
141 * USCHED_SET(syscall)
144 * Setting up a proc's usched.
156 sys_usched_set(struct usched_set_args *uap)
158 struct proc *p = curthread->td_proc;
159 struct usched *item; /* temporaly for TAILQ processing */
161 char buffer[NAME_LENGTH];
165 /* USCHED_GET_CPU doesn't require root privileges. */
166 if ((uap->cmd != USCHED_GET_CPU) && (uap->cmd != USCHED_DEL_CPU) &&
167 (error = priv_check(curthread, PRIV_ROOT)) != 0)
170 if (uap->pid != 0 && uap->pid != curthread->td_proc->p_pid)
173 lp = curthread->td_lwp;
175 case USCHED_SET_SCHEDULER:
176 if ((error = copyinstr(uap->data, buffer, sizeof(buffer),
179 TAILQ_FOREACH(item, &usched_list, entry) {
180 if ((strcmp(item->name, buffer) == 0))
185 * If the scheduler for a process is being changed, disassociate
186 * the old scheduler before switching to the new one.
188 * XXX we might have to add an additional ABI call to do a 'full
189 * disassociation' and another ABI call to do a 'full
192 /* XXX lwp have to deal with multiple lwps here */
193 if (p->p_nthreads != 1)
195 if (item && item != p->p_usched) {
197 p->p_usched->release_curproc(ONLY_LWP_IN_PROC(p));
199 } else if (item == NULL) {
204 if (uap->bytes != sizeof(int))
206 error = copyin(uap->data, &cpuid, sizeof(int));
209 if (cpuid < 0 || cpuid >= ncpus) {
213 if ((smp_active_mask & (1 << cpuid)) == 0) {
217 lp->lwp_cpumask = 1 << cpuid;
218 if (cpuid != mycpu->gd_cpuid)
219 lwkt_migratecpu(cpuid);
222 if (uap->bytes != sizeof(int))
224 error = copyout(&(mycpu->gd_cpuid), uap->data, sizeof(int));
227 if (uap->bytes != sizeof(int))
229 error = copyin(uap->data, &cpuid, sizeof(int));
232 if (cpuid < 0 || cpuid >= ncpus) {
236 if (!(smp_active_mask & (1 << cpuid))) {
240 lp->lwp_cpumask |= 1 << cpuid;
243 if (uap->bytes != sizeof(int))
245 error = copyin(uap->data, &cpuid, sizeof(int));
248 if (cpuid < 0 || cpuid >= ncpus) {
252 lp = curthread->td_lwp;
253 mask = lp->lwp_cpumask & smp_active_mask & ~(1 << cpuid);
257 lp->lwp_cpumask &= ~(1 << cpuid);
258 if ((lp->lwp_cpumask & mycpu->gd_cpumask) == 0) {
259 cpuid = bsfl(lp->lwp_cpumask & smp_active_mask);
260 lwkt_migratecpu(cpuid);