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 "opt_ktrace.h" 10 11 #include <sys/param.h> 12 #include <sys/systm.h> 13 #include <sys/kernel.h> 14 #include <sys/ktr.h> 15 #include <sys/kthread.h> 16 #include <sys/lock.h> 17 #include <sys/mutex.h> 18 #include <sys/pcpu.h> 19 #include <sys/proc.h> 20 #include <sys/resourcevar.h> 21 #include <sys/sched.h> 22 #include <sys/smp.h> 23 #include <sys/unistd.h> 24 #ifdef KTRACE 25 #include <sys/uio.h> 26 #include <sys/ktrace.h> 27 #endif 28 29 static void idle_setup(void *dummy); 30 SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL) 31 32 static void idle_proc(void *dummy); 33 34 /* 35 * Setup per-cpu idle process contexts. The AP's shouldn't be running or 36 * accessing their idle processes at this point, so don't bother with 37 * locking. 38 */ 39 static void 40 idle_setup(void *dummy) 41 { 42 #ifdef SMP 43 struct pcpu *pc; 44 #endif 45 struct proc *p; 46 struct thread *td; 47 int error; 48 49 #ifdef SMP 50 SLIST_FOREACH(pc, &cpuhead, pc_allcpu) { 51 error = kthread_create(idle_proc, NULL, &p, 52 RFSTOPPED | RFHIGHPID, 0, "idle: cpu%d", pc->pc_cpuid); 53 pc->pc_idlethread = FIRST_THREAD_IN_PROC(p); 54 if (pc->pc_curthread == NULL) { 55 pc->pc_curthread = pc->pc_idlethread; 56 pc->pc_idlethread->td_critnest = 0; 57 } 58 #else 59 error = kthread_create(idle_proc, NULL, &p, 60 RFSTOPPED | RFHIGHPID, 0, "idle"); 61 PCPU_SET(idlethread, FIRST_THREAD_IN_PROC(p)); 62 #endif 63 if (error) 64 panic("idle_setup: kthread_create error %d\n", error); 65 66 PROC_LOCK(p); 67 p->p_flag |= P_NOLOAD; 68 mtx_lock_spin(&sched_lock); 69 p->p_state = PRS_NORMAL; 70 td = FIRST_THREAD_IN_PROC(p); 71 td->td_state = TDS_CAN_RUN; 72 td->td_flags |= TDF_IDLETD; 73 mtx_unlock_spin(&sched_lock); 74 PROC_UNLOCK(p); 75 #ifdef SMP 76 } 77 #endif 78 } 79 80 /* 81 * idle process context 82 */ 83 static void 84 idle_proc(void *dummy) 85 { 86 #ifdef DIAGNOSTIC 87 int count; 88 #endif 89 struct thread *td; 90 struct proc *p; 91 92 td = curthread; 93 p = td->td_proc; 94 for (;;) { 95 mtx_assert(&Giant, MA_NOTOWNED); 96 97 #ifdef DIAGNOSTIC 98 count = 0; 99 100 while (count >= 0 && sched_runnable() == 0) { 101 #else 102 while (sched_runnable() == 0) { 103 #endif 104 /* 105 * This is a good place to put things to be done in 106 * the background, including sanity checks. 107 */ 108 109 #ifdef DIAGNOSTIC 110 if (count++ < 0) 111 CTR0(KTR_PROC, "idle_proc: timed out waiting" 112 " for a process"); 113 #endif 114 115 #ifdef __i386__ 116 cpu_idle(); 117 #endif 118 } 119 120 mtx_lock_spin(&sched_lock); 121 p->p_stats->p_ru.ru_nvcsw++; 122 td->td_state = TDS_CAN_RUN; 123 mi_switch(); 124 mtx_unlock_spin(&sched_lock); 125 } 126 } 127