1 /*- 2 * Copyright (c) 2000, All rights reserved. See /usr/src/COPYRIGHT 3 * 4 */ 5 6 #include <sys/cdefs.h> 7 __FBSDID("$FreeBSD$"); 8 9 #include <sys/param.h> 10 #include <sys/systm.h> 11 #include <sys/kernel.h> 12 #include <sys/kthread.h> 13 #include <sys/lock.h> 14 #include <sys/mutex.h> 15 #include <sys/proc.h> 16 #include <sys/resourcevar.h> 17 #include <sys/sched.h> 18 #include <sys/unistd.h> 19 20 static void idle_setup(void *dummy); 21 SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL) 22 23 static void idle_proc(void *dummy); 24 25 /* 26 * Set up per-cpu idle process contexts. The AP's shouldn't be running or 27 * accessing their idle processes at this point, so don't bother with 28 * locking. 29 */ 30 static void 31 idle_setup(void *dummy) 32 { 33 #ifdef SMP 34 struct pcpu *pc; 35 #endif 36 struct proc *p; 37 struct thread *td; 38 int error; 39 40 #ifdef SMP 41 SLIST_FOREACH(pc, &cpuhead, pc_allcpu) { 42 error = kthread_create(idle_proc, NULL, &p, 43 RFSTOPPED | RFHIGHPID, 0, "idle: cpu%d", pc->pc_cpuid); 44 pc->pc_idlethread = FIRST_THREAD_IN_PROC(p); 45 if (pc->pc_curthread == NULL) { 46 pc->pc_curthread = pc->pc_idlethread; 47 pc->pc_idlethread->td_critnest = 0; 48 } 49 #else 50 error = kthread_create(idle_proc, NULL, &p, 51 RFSTOPPED | RFHIGHPID, 0, "idle"); 52 PCPU_SET(idlethread, FIRST_THREAD_IN_PROC(p)); 53 #endif 54 if (error) 55 panic("idle_setup: kthread_create error %d\n", error); 56 57 PROC_LOCK(p); 58 p->p_flag |= P_NOLOAD; 59 mtx_lock_spin(&sched_lock); 60 td = FIRST_THREAD_IN_PROC(p); 61 td->td_state = TDS_CAN_RUN; 62 td->td_flags |= TDF_IDLETD; 63 mtx_unlock_spin(&sched_lock); 64 PROC_UNLOCK(p); 65 #ifdef SMP 66 } 67 #endif 68 } 69 70 /* 71 * The actual idle process. 72 */ 73 static void 74 idle_proc(void *dummy) 75 { 76 struct proc *p; 77 struct thread *td; 78 79 td = curthread; 80 p = td->td_proc; 81 for (;;) { 82 mtx_assert(&Giant, MA_NOTOWNED); 83 84 while (sched_runnable() == 0) 85 cpu_idle(); 86 87 mtx_lock_spin(&sched_lock); 88 td->td_state = TDS_CAN_RUN; 89 mi_switch(SW_VOL); 90 mtx_unlock_spin(&sched_lock); 91 } 92 } 93