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