sys/kern/kern_idle.c

   1 /*-
   2  * Copyright (C) 2000-2004 The FreeBSD Project. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   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.
  12  *
  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
  23  * SUCH DAMAGE.
  24  */
  25
  26 #include <sys/cdefs.h>
  27 __FBSDID("$FreeBSD$");
  28
  29 #include <sys/param.h>
  30 #include <sys/systm.h>
  31 #include <sys/kernel.h>
  32 #include <sys/kthread.h>
  33 #include <sys/lock.h>
  34 #include <sys/mutex.h>
  35 #include <sys/proc.h>
  36 #include <sys/resourcevar.h>
  37 #include <sys/sched.h>
  38 #include <sys/unistd.h>
  39 #ifdef SMP
  40 #include <sys/smp.h>
  41 #endif
  42
  43 static void idle_setup(void *dummy);
  44 SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL);
  45
  46 /*
  47  * Set up per-cpu idle process contexts.  The AP's shouldn't be running or
  48  * accessing their idle processes at this point, so don't bother with
  49  * locking.
  50  */
  51 static void
  52 idle_setup(void *dummy)
  53 {
  54 #ifdef SMP
  55         struct pcpu *pc;
  56 #endif
  57         struct proc *p;
  58         struct thread *td;
  59         int error;
  60
  61         p = NULL; /* start with no idle process */
  62 #ifdef SMP
  63         SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
  64 #endif
  65 #ifdef SMP
  66                 error = kproc_kthread_add(sched_idletd, NULL, &p, &td,
  67                     RFSTOPPED | RFHIGHPID, 0, "idle", "idle: cpu%d", pc->pc_cpuid);
  68                 pc->pc_idlethread = td;
  69 #else
  70                 error = kproc_kthread_add(sched_idletd, NULL, &p, &td,
  71                     RFSTOPPED | RFHIGHPID, 0, "idle", "idle");
  72                 PCPU_SET(idlethread, td);
  73 #endif
  74                 if (error)
  75                         panic("idle_setup: kproc_create error %d\n", error);
  76
  77                 p->p_flag |= P_NOLOAD;
  78                 thread_lock(td);
  79                 TD_SET_CAN_RUN(td);
  80                 td->td_flags |= TDF_IDLETD;
  81                 sched_class(td, PRI_IDLE);
  82                 sched_prio(td, PRI_MAX_IDLE);
  83                 thread_unlock(td);
  84 #ifdef SMP
  85         }
  86 #endif
  87 }