1 /*- 2 * Copyright (c) 2000, All rights reserved. See /usr/src/COPYRIGHT 3 * 4 * $FreeBSD$ 5 */ 6 7 #include "opt_ktrace.h" 8 9 #include <sys/param.h> 10 #include <sys/systm.h> 11 #include <sys/kernel.h> 12 #include <sys/ktr.h> 13 #include <sys/kthread.h> 14 #include <sys/lock.h> 15 #include <sys/mutex.h> 16 #include <sys/pcpu.h> 17 #include <sys/proc.h> 18 #include <sys/resourcevar.h> 19 #include <sys/smp.h> 20 #include <sys/unistd.h> 21 #ifdef KTRACE 22 #include <sys/uio.h> 23 #include <sys/ktrace.h> 24 #endif 25 26 static void idle_setup(void *dummy); 27 SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL) 28 29 static void idle_proc(void *dummy); 30 31 /* 32 * Setup per-cpu idle process contexts. The AP's shouldn't be running or 33 * accessing their idle processes at this point, so don't bother with 34 * locking. 35 */ 36 static void 37 idle_setup(void *dummy) 38 { 39 #ifdef SMP 40 struct pcpu *pc; 41 #endif 42 struct proc *p; 43 struct thread *td; 44 int error; 45 46 #ifdef SMP 47 SLIST_FOREACH(pc, &cpuhead, pc_allcpu) { 48 error = kthread_create(idle_proc, NULL, &p, 49 RFSTOPPED | RFHIGHPID, "idle: cpu%d", pc->pc_cpuid); 50 pc->pc_idlethread = FIRST_THREAD_IN_PROC(p); 51 if (pc->pc_curthread == NULL) { 52 pc->pc_curthread = pc->pc_idlethread; 53 pc->pc_idlethread->td_critnest = 0; 54 } 55 #else 56 error = kthread_create(idle_proc, NULL, &p, 57 RFSTOPPED | RFHIGHPID, "idle"); 58 PCPU_SET(idlethread, FIRST_THREAD_IN_PROC(p)); 59 #endif 60 if (error) 61 panic("idle_setup: kthread_create error %d\n", error); 62 63 p->p_flag |= P_NOLOAD; 64 td = FIRST_THREAD_IN_PROC(p); 65 td->td_state = TDS_RUNQ; 66 td->td_kse->ke_state = KES_ONRUNQ; 67 td->td_kse->ke_flags |= KEF_IDLEKSE; 68 #ifdef SMP 69 } 70 #endif 71 } 72 73 /* 74 * idle process context 75 */ 76 static void 77 idle_proc(void *dummy) 78 { 79 #ifdef DIAGNOSTIC 80 int count; 81 #endif 82 struct thread *td; 83 struct proc *p; 84 85 td = curthread; 86 p = td->td_proc; 87 td->td_state = TDS_RUNNING; 88 td->td_kse->ke_state = KES_RUNNING; 89 for (;;) { 90 mtx_assert(&Giant, MA_NOTOWNED); 91 92 #ifdef DIAGNOSTIC 93 count = 0; 94 95 while (count >= 0 && kserunnable() == 0) { 96 #else 97 while (kserunnable() == 0) { 98 #endif 99 /* 100 * This is a good place to put things to be done in 101 * the background, including sanity checks. 102 */ 103 104 #ifdef DIAGNOSTIC 105 if (count++ < 0) 106 CTR0(KTR_PROC, "idle_proc: timed out waiting" 107 " for a process"); 108 #endif 109 110 #ifdef __i386__ 111 cpu_idle(); 112 #endif 113 } 114 115 mtx_lock_spin(&sched_lock); 116 p->p_stats->p_ru.ru_nvcsw++; 117 mi_switch(); 118 td->td_kse->ke_state = KES_RUNNING; 119 mtx_unlock_spin(&sched_lock); 120 } 121 } 122