2 * Copyright (C) 2000-2004 The FreeBSD Project. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
32 #include <sys/kthread.h>
34 #include <sys/mutex.h>
36 #include <sys/resourcevar.h>
37 #include <sys/sched.h>
38 #include <sys/unistd.h>
43 static void idle_setup(void *dummy);
44 SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL)
46 static void idle_proc(void *dummy);
49 * Set up per-cpu idle process contexts. The AP's shouldn't be running or
50 * accessing their idle processes at this point, so don't bother with
54 idle_setup(void *dummy)
64 SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
65 error = kthread_create(idle_proc, NULL, &p,
66 RFSTOPPED | RFHIGHPID, 0, "idle: cpu%d", pc->pc_cpuid);
67 pc->pc_idlethread = FIRST_THREAD_IN_PROC(p);
68 if (pc->pc_curthread == NULL) {
69 pc->pc_curthread = pc->pc_idlethread;
70 pc->pc_idlethread->td_critnest = 0;
73 error = kthread_create(idle_proc, NULL, &p,
74 RFSTOPPED | RFHIGHPID, 0, "idle");
75 PCPU_SET(idlethread, FIRST_THREAD_IN_PROC(p));
78 panic("idle_setup: kthread_create error %d\n", error);
81 p->p_flag |= P_NOLOAD;
82 mtx_lock_spin(&sched_lock);
83 td = FIRST_THREAD_IN_PROC(p);
85 td->td_flags |= TDF_IDLETD;
86 sched_class(td->td_ksegrp, PRI_IDLE);
87 sched_prio(td, PRI_MAX_IDLE);
88 mtx_unlock_spin(&sched_lock);
96 * The actual idle process.
99 idle_proc(void *dummy)
110 mycpu = PCPU_GET(cpumask);
111 mtx_lock_spin(&sched_lock);
112 idle_cpus_mask |= mycpu;
113 mtx_unlock_spin(&sched_lock);
116 mtx_assert(&Giant, MA_NOTOWNED);
118 while (sched_runnable() == 0)
121 mtx_lock_spin(&sched_lock);
123 idle_cpus_mask &= ~mycpu;
125 mi_switch(SW_VOL, NULL);
127 idle_cpus_mask |= mycpu;
129 mtx_unlock_spin(&sched_lock);