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
= -1;
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_dummy
, USCH_ADD
);
70 if (defsched
== NULL
)
72 if (strcmp(defsched
, "bsd4") == 0)
74 kprintf("WARNING: Running dummy userland scheduler\n");
75 return(&usched_dummy
);
82 * Add/remove usched to/from list.
85 * usched - pointer to target scheduler
86 * action - addition or removal ?
93 usched_ctl(struct usched
*usched
, int action
)
95 struct usched
*item
; /* temporaly for TAILQ processing */
101 * Make sure it isn't already on the list
104 TAILQ_FOREACH(item
, &usched_list
, entry
) {
105 KKASSERT(item
!= usched
);
109 * Optional callback to the scheduler before we officially
110 * add it to the list.
112 if (usched
->usched_register
)
113 usched
->usched_register();
114 TAILQ_INSERT_TAIL(&usched_list
, usched
, entry
);
118 * Do not allow the default scheduler to be removed
120 if (strcmp(usched
->name
, "bsd4") == 0) {
124 TAILQ_FOREACH(item
, &usched_list
, entry
) {
129 if (item
->usched_unregister
)
130 item
->usched_unregister();
131 TAILQ_REMOVE(&usched_list
, item
, entry
);
144 * USCHED_SET(syscall)
147 * Setting up a proc's usched.
161 sys_usched_set(struct usched_set_args
*uap
)
163 struct proc
*p
= curthread
->td_proc
;
164 struct usched
*item
; /* temporaly for TAILQ processing */
166 char buffer
[NAME_LENGTH
];
171 if (uap
->pid
!= 0 && uap
->pid
!= curthread
->td_proc
->p_pid
)
174 lp
= curthread
->td_lwp
;
178 case USCHED_SET_SCHEDULER
:
179 if ((error
= priv_check(curthread
, PRIV_SCHED_SET
)) != 0)
181 error
= copyinstr(uap
->data
, buffer
, sizeof(buffer
), NULL
);
184 TAILQ_FOREACH(item
, &usched_list
, entry
) {
185 if ((strcmp(item
->name
, buffer
) == 0))
190 * If the scheduler for a process is being changed, disassociate
191 * the old scheduler before switching to the new one.
193 * XXX we might have to add an additional ABI call to do a 'full
194 * disassociation' and another ABI call to do a 'full
197 /* XXX lwp have to deal with multiple lwps here */
198 if (p
->p_nthreads
!= 1) {
202 if (item
&& item
!= p
->p_usched
) {
204 p
->p_usched
->release_curproc(ONLY_LWP_IN_PROC(p
));
206 } else if (item
== NULL
) {
211 if ((error
= priv_check(curthread
, PRIV_SCHED_CPUSET
)) != 0)
213 if (uap
->bytes
!= sizeof(int)) {
217 error
= copyin(uap
->data
, &cpuid
, sizeof(int));
220 if (cpuid
< 0 || cpuid
>= ncpus
) {
224 if ((smp_active_mask
& (1 << cpuid
)) == 0) {
228 lp
->lwp_cpumask
= 1 << cpuid
;
229 if (cpuid
!= mycpu
->gd_cpuid
)
230 lwkt_migratecpu(cpuid
);
233 /* USCHED_GET_CPU doesn't require special privileges. */
234 if (uap
->bytes
!= sizeof(int)) {
238 error
= copyout(&(mycpu
->gd_cpuid
), uap
->data
, sizeof(int));
241 if ((error
= priv_check(curthread
, PRIV_SCHED_CPUSET
)) != 0)
243 if (uap
->bytes
!= sizeof(int)) {
247 error
= copyin(uap
->data
, &cpuid
, sizeof(int));
250 if (cpuid
< 0 || cpuid
>= ncpus
) {
254 if (!(smp_active_mask
& (1 << cpuid
))) {
258 lp
->lwp_cpumask
|= 1 << cpuid
;
261 /* USCHED_DEL_CPU doesn't require special privileges. */
262 if (uap
->bytes
!= sizeof(int)) {
266 error
= copyin(uap
->data
, &cpuid
, sizeof(int));
269 if (cpuid
< 0 || cpuid
>= ncpus
) {
273 lp
= curthread
->td_lwp
;
274 mask
= lp
->lwp_cpumask
& smp_active_mask
& ~(1 << cpuid
);
278 lp
->lwp_cpumask
&= ~(1 << cpuid
);
279 if ((lp
->lwp_cpumask
& mycpu
->gd_cpumask
) == 0) {
280 cpuid
= bsfl(lp
->lwp_cpumask
& smp_active_mask
);
281 lwkt_migratecpu(cpuid
);