/*-
* Copyright (C) 2000-2004 The FreeBSD Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/unistd.h>
#ifdef SMP
#include <sys/smp.h>
#endif
static void idle_setup(void *dummy);
SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL)
static void idle_proc(void *dummy);
/*
* Set up per-cpu idle process contexts. The AP's shouldn't be running or
* accessing their idle processes at this point, so don't bother with
* locking.
*/
static void
idle_setup(void *dummy)
{
#ifdef SMP
struct pcpu *pc;
#endif
struct proc *p;
struct thread *td;
int error;
#ifdef SMP
SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
error = kthread_create(idle_proc, NULL, &p,
RFSTOPPED | RFHIGHPID, 0, "idle: cpu%d", pc->pc_cpuid);
pc->pc_idlethread = FIRST_THREAD_IN_PROC(p);
if (pc->pc_curthread == NULL) {
pc->pc_curthread = pc->pc_idlethread;
pc->pc_idlethread->td_critnest = 0;
}
#else
error = kthread_create(idle_proc, NULL, &p,
RFSTOPPED | RFHIGHPID, 0, "idle");
PCPU_SET(idlethread, FIRST_THREAD_IN_PROC(p));
#endif
if (error)
panic("idle_setup: kthread_create error %d\n", error);
PROC_LOCK(p);
p->p_flag |= P_NOLOAD;
mtx_lock_spin(&sched_lock);
td = FIRST_THREAD_IN_PROC(p);
TD_SET_CAN_RUN(td);
td->td_flags |= TDF_IDLETD;
td->td_priority = PRI_MAX_IDLE;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
#ifdef SMP
}
#endif
}
/*
* The actual idle process.
*/
static void
idle_proc(void *dummy)
{
struct proc *p;
struct thread *td;
#ifdef SMP
cpumask_t mycpu;
#endif
td = curthread;
p = td->td_proc;
#ifdef SMP
mycpu = PCPU_GET(cpumask);
mtx_lock_spin(&sched_lock);
idle_cpus_mask |= mycpu;
mtx_unlock_spin(&sched_lock);
#endif
for (;;) {
mtx_assert(&Giant, MA_NOTOWNED);
while (sched_runnable() == 0)
cpu_idle();
mtx_lock_spin(&sched_lock);
#ifdef SMP
idle_cpus_mask &= ~mycpu;
#endif
mi_switch(SW_VOL, NULL);
#ifdef SMP
idle_cpus_mask |= mycpu;
#endif
mtx_unlock_spin(&sched_lock);
}
}
