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>
45 #include <sys/mplock2.h>
47 #include <machine/smp.h>
49 static TAILQ_HEAD(, usched) usched_list = TAILQ_HEAD_INITIALIZER(usched_list);
51 cpumask_t usched_mastermask = CPUMASK_INITIALIZER_ALLONES;
54 * Called from very low level boot code, i386/i386/machdep.c/init386().
55 * We cannot do anything fancy. no malloc's, no nothing other then
56 * static initialization.
63 defsched = kgetenv("kern.user_scheduler");
66 * Add various userland schedulers to the system.
68 usched_ctl(&usched_bsd4, USCH_ADD);
69 usched_ctl(&usched_dfly, USCH_ADD);
70 usched_ctl(&usched_dummy, USCH_ADD);
71 if (defsched == NULL )
73 if (strcmp(defsched, "bsd4") == 0)
75 if (strcmp(defsched, "dfly") == 0)
77 kprintf("WARNING: Running dummy userland scheduler\n");
78 return(&usched_dummy);
85 * Add/remove usched to/from list.
88 * usched - pointer to target scheduler
89 * action - addition or removal ?
96 usched_ctl(struct usched *usched, int action)
98 struct usched *item; /* temporaly for TAILQ processing */
104 * Make sure it isn't already on the list
107 TAILQ_FOREACH(item, &usched_list, entry) {
108 KKASSERT(item != usched);
112 * Optional callback to the scheduler before we officially
113 * add it to the list.
115 if (usched->usched_register)
116 usched->usched_register();
117 TAILQ_INSERT_TAIL(&usched_list, usched, entry);
121 * Do not allow the default scheduler to be removed
123 if (strcmp(usched->name, "bsd4") == 0) {
127 TAILQ_FOREACH(item, &usched_list, entry) {
132 if (item->usched_unregister)
133 item->usched_unregister();
134 TAILQ_REMOVE(&usched_list, item, entry);
147 * Called from the scheduler clock on each cpu independently at the
148 * common scheduling rate. If th scheduler clock interrupted a running
149 * lwp the lp will be non-NULL.
152 usched_schedulerclock(struct lwp *lp, sysclock_t periodic, sysclock_t time)
156 TAILQ_FOREACH(item, &usched_list, entry) {
157 if (lp && lp->lwp_proc->p_usched == item)
158 item->schedulerclock(lp, periodic, time);
160 item->schedulerclock(NULL, periodic, time);
165 * USCHED_SET(syscall)
168 * Setting up a proc's usched.
177 * EFBIG - error (invalid cpu#)
178 * EPERM - error (failed to delete cpu#)
179 * EINVAL - error (other reasons)
184 sys_usched_set(struct usched_set_args *uap)
186 struct proc *p = curthread->td_proc;
187 struct usched *item; /* temporaly for TAILQ processing */
189 char buffer[NAME_LENGTH];
194 if (uap->pid != 0 && uap->pid != curthread->td_proc->p_pid)
197 lp = curthread->td_lwp;
201 case USCHED_SET_SCHEDULER:
202 if ((error = priv_check(curthread, PRIV_SCHED_SET)) != 0)
204 error = copyinstr(uap->data, buffer, sizeof(buffer), NULL);
207 TAILQ_FOREACH(item, &usched_list, entry) {
208 if ((strcmp(item->name, buffer) == 0))
213 * If the scheduler for a process is being changed, disassociate
214 * the old scheduler before switching to the new one.
216 * XXX we might have to add an additional ABI call to do a 'full
217 * disassociation' and another ABI call to do a 'full
220 /* XXX lwp have to deal with multiple lwps here */
221 if (p->p_nthreads != 1) {
225 if (item && item != p->p_usched) {
227 p->p_usched->release_curproc(ONLY_LWP_IN_PROC(p));
228 p->p_usched->heuristic_exiting(ONLY_LWP_IN_PROC(p), p);
230 } else if (item == NULL) {
235 if ((error = priv_check(curthread, PRIV_SCHED_CPUSET)) != 0)
237 if (uap->bytes != sizeof(int)) {
241 error = copyin(uap->data, &cpuid, sizeof(int));
244 if (cpuid < 0 || cpuid >= ncpus) {
248 if (CPUMASK_TESTBIT(smp_active_mask, cpuid) == 0) {
252 CPUMASK_ASSBIT(lp->lwp_cpumask, cpuid);
253 if (cpuid != mycpu->gd_cpuid) {
254 lwkt_migratecpu(cpuid);
255 p->p_usched->changedcpu(lp);
259 /* USCHED_GET_CPU doesn't require special privileges. */
260 if (uap->bytes != sizeof(int)) {
264 error = copyout(&(mycpu->gd_cpuid), uap->data, sizeof(int));
267 if ((error = priv_check(curthread, PRIV_SCHED_CPUSET)) != 0)
269 if (uap->bytes != sizeof(int)) {
273 error = copyin(uap->data, &cpuid, sizeof(int));
276 if (cpuid < 0 || cpuid >= ncpus) {
280 if (CPUMASK_TESTBIT(smp_active_mask, cpuid) == 0) {
284 CPUMASK_ORBIT(lp->lwp_cpumask, cpuid);
287 /* USCHED_DEL_CPU doesn't require special privileges. */
288 if (uap->bytes != sizeof(int)) {
292 error = copyin(uap->data, &cpuid, sizeof(int));
295 if (cpuid < 0 || cpuid >= ncpus) {
299 lp = curthread->td_lwp;
300 mask = lp->lwp_cpumask;
301 CPUMASK_ANDMASK(mask, smp_active_mask);
302 CPUMASK_NANDBIT(mask, cpuid);
303 if (CPUMASK_TESTZERO(mask)) {
306 CPUMASK_NANDBIT(lp->lwp_cpumask, cpuid);
307 if (CPUMASK_TESTMASK(lp->lwp_cpumask,
308 mycpu->gd_cpumask) == 0) {
309 mask = lp->lwp_cpumask;
310 CPUMASK_ANDMASK(mask, smp_active_mask);
311 cpuid = BSFCPUMASK(mask);
312 lwkt_migratecpu(cpuid);
313 p->p_usched->changedcpu(lp);