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 #if 0 22 #include <vm/vm.h> 23 #include <vm/vm_extern.h> 24 #endif 25 #ifdef KTRACE 26 #include <sys/uio.h> 27 #include <sys/ktrace.h> 28 #endif 29 30 static void idle_setup(void *dummy); 31 SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL) 32 33 static void idle_proc(void *dummy); 34 35 /* 36 * Setup per-cpu idle process contexts. The AP's shouldn't be running or 37 * accessing their idle processes at this point, so don't bother with 38 * locking. 39 */ 40 static void 41 idle_setup(void *dummy) 42 { 43 #ifdef SMP 44 struct globaldata *gd; 45 #endif 46 struct proc *p; 47 int error; 48 49 #ifdef SMP 50 SLIST_FOREACH(gd, &cpuhead, gd_allcpu) { 51 error = kthread_create(idle_proc, NULL, &p, 52 RFSTOPPED | RFHIGHPID, "idle: cpu%d", gd->gd_cpuid); 53 gd->gd_idleproc = p; 54 if (gd->gd_curproc == NULL) 55 gd->gd_curproc = p; 56 #else 57 error = kthread_create(idle_proc, NULL, &p, 58 RFSTOPPED | RFHIGHPID, "idle"); 59 PCPU_SET(idleproc, p); 60 #endif 61 if (error) 62 panic("idle_setup: kthread_create error %d\n", error); 63 64 p->p_flag |= P_NOLOAD; 65 p->p_stat = SRUN; 66 #ifdef SMP 67 } 68 #endif 69 } 70 71 /* 72 * idle process context 73 */ 74 static void 75 idle_proc(void *dummy) 76 { 77 #ifdef DIAGNOSTIC 78 int count; 79 #endif 80 81 for (;;) { 82 mtx_assert(&Giant, MA_NOTOWNED); 83 84 #ifdef DIAGNOSTIC 85 count = 0; 86 87 while (count >= 0 && procrunnable() == 0) { 88 #else 89 while (procrunnable() == 0) { 90 #endif 91 /* 92 * This is a good place to put things to be done in 93 * the background, including sanity checks. 94 */ 95 96 #ifdef DIAGNOSTIC 97 if (count++ < 0) 98 CTR0(KTR_PROC, "idle_proc: timed out waiting" 99 " for a process"); 100 #endif 101 102 #if 0 103 if (vm_page_zero_idle() != 0) 104 continue; 105 #endif 106 107 #ifdef __i386__ 108 cpu_idle(); 109 #endif 110 } 111 112 mtx_lock_spin(&sched_lock); 113 curproc->p_stats->p_ru.ru_nvcsw++; 114 mi_switch(); 115 mtx_unlock_spin(&sched_lock); 116 } 117 } 118