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 int error; 44 45 #ifdef SMP 46 SLIST_FOREACH(pc, &cpuhead, pc_allcpu) { 47 error = kthread_create(idle_proc, NULL, &p, 48 RFSTOPPED | RFHIGHPID, "idle: cpu%d", pc->pc_cpuid); 49 pc->pc_idlethread = FIRST_THREAD_IN_PROC(p); 50 if (pc->pc_curthread == NULL) { 51 pc->pc_curthread = pc->pc_idlethread; 52 pc->pc_idlethread->td_critnest = 0; 53 } 54 #else 55 error = kthread_create(idle_proc, NULL, &p, 56 RFSTOPPED | RFHIGHPID, "idle"); 57 PCPU_SET(idlethread, FIRST_THREAD_IN_PROC(p)); 58 #endif 59 if (error) 60 panic("idle_setup: kthread_create error %d\n", error); 61 62 p->p_flag |= P_NOLOAD; 63 p->p_stat = SRUN; 64 #ifdef SMP 65 } 66 #endif 67 } 68 69 /* 70 * idle process context 71 */ 72 static void 73 idle_proc(void *dummy) 74 { 75 #ifdef DIAGNOSTIC 76 int count; 77 #endif 78 79 for (;;) { 80 mtx_assert(&Giant, MA_NOTOWNED); 81 82 #ifdef DIAGNOSTIC 83 count = 0; 84 85 while (count >= 0 && procrunnable() == 0) { 86 #else 87 while (procrunnable() == 0) { 88 #endif 89 /* 90 * This is a good place to put things to be done in 91 * the background, including sanity checks. 92 */ 93 94 #ifdef DIAGNOSTIC 95 if (count++ < 0) 96 CTR0(KTR_PROC, "idle_proc: timed out waiting" 97 " for a process"); 98 #endif 99 100 #ifdef __i386__ 101 cpu_idle(); 102 #endif 103 } 104 105 mtx_lock_spin(&sched_lock); 106 curproc->p_stats->p_ru.ru_nvcsw++; 107 mi_switch(); 108 mtx_unlock_spin(&sched_lock); 109 } 110 } 111