kern_kthread.c revision 1.17
1/* $NetBSD: kern_kthread.c,v 1.17 2007/07/09 21:10:52 ad Exp $ */ 2 3/*- 4 * Copyright (c) 1998, 1999, 2007 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 9 * NASA Ames Research Center, and by Andrew Doran. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the NetBSD 22 * Foundation, Inc. and its contributors. 23 * 4. Neither the name of The NetBSD Foundation nor the names of its 24 * contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 37 * POSSIBILITY OF SUCH DAMAGE. 38 */ 39 40#include <sys/cdefs.h> 41__KERNEL_RCSID(0, "$NetBSD: kern_kthread.c,v 1.17 2007/07/09 21:10:52 ad Exp $"); 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/kernel.h> 46#include <sys/kthread.h> 47#include <sys/proc.h> 48#include <sys/sched.h> 49#include <sys/kmem.h> 50 51#include <uvm/uvm_extern.h> 52 53/* 54 * note that stdarg.h and the ansi style va_start macro is used for both 55 * ansi and traditional c complers. 56 * XXX: this requires that stdarg.h define: va_alist and va_dcl 57 */ 58#include <machine/stdarg.h> 59 60/* 61 * Fork a kernel thread. Any process can request this to be done. 62 */ 63int 64kthread_create(pri_t pri, int flag, struct cpu_info *ci, 65 void (*func)(void *), void *arg, 66 lwp_t **lp, const char *fmt, ...) 67{ 68 lwp_t *l; 69 vaddr_t uaddr; 70 bool inmem; 71 int error; 72 va_list ap; 73 74 inmem = uvm_uarea_alloc(&uaddr); 75 if (uaddr == 0) 76 return ENOMEM; 77 error = newlwp(&lwp0, &proc0, uaddr, inmem, LWP_DETACHED, NULL, 0, 78 func, arg, &l); 79 if (error) { 80 uvm_uarea_free(uaddr); 81 return error; 82 } 83 uvm_lwp_hold(l); 84 if (fmt != NULL) { 85 l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP); 86 if (l->l_name == NULL) { 87 lwp_exit(l); 88 return ENOMEM; 89 } 90 va_start(ap, fmt); 91 vsnprintf(l->l_name, MAXCOMLEN, fmt, ap); 92 va_end(ap); 93 } 94 95 /* 96 * Set parameters. 97 */ 98 if ((flag & KTHREAD_INTR) != 0) { 99 KASSERT((flag & KTHREAD_MPSAFE) != 0); 100 } 101 102 mutex_enter(&proc0.p_smutex); 103 lwp_lock(l); 104 if (pri == PRI_NONE) { 105 /* Minimum kernel priority level. */ 106 pri = PUSER - 1; 107 } 108 l->l_usrpri = pri; 109 l->l_priority = pri; 110 if (ci != NULL) { 111 if (ci != l->l_cpu) { 112 lwp_unlock_to(l, ci->ci_schedstate.spc_mutex); 113 lwp_lock(l); 114 } 115 l->l_flag |= LW_BOUND; 116 l->l_cpu = ci; 117 } 118 if ((flag & KTHREAD_INTR) != 0) 119 l->l_flag |= LW_INTR; 120 if ((flag & KTHREAD_MPSAFE) != 0) 121 l->l_pflag |= LP_MPSAFE; 122 123 /* 124 * Set the new LWP running, unless the caller has requested 125 * otherwise. 126 */ 127 if ((flag & KTHREAD_IDLE) == 0) { 128 l->l_stat = LSRUN; 129 sched_enqueue(l, false); 130 } 131 132 /* 133 * The LWP is not created suspended or stopped and cannot be set 134 * into those states later, so must be considered runnable. 135 */ 136 proc0.p_nrlwps++; 137 lwp_unlock(l); 138 mutex_exit(&proc0.p_smutex); 139 140 /* All done! */ 141 if (lp != NULL) 142 *lp = l; 143 144 return (0); 145} 146 147/* 148 * Cause a kernel thread to exit. Assumes the exiting thread is the 149 * current context. 150 */ 151void 152kthread_exit(int ecode) 153{ 154 lwp_t *l = curlwp; 155 156 /* We can't do much with the exit code, so just report it. */ 157 if (ecode != 0) 158 printf("WARNING: kthread `%s' (%d) exits with status %d\n", 159 l->l_name, l->l_lid, ecode); 160 161 /* And exit.. */ 162 lwp_exit(l); 163 164 /* 165 * XXX Fool the compiler. Making exit1() __noreturn__ is a can 166 * XXX of worms right now. 167 */ 168 for (;;) 169 ; 170} 171 172/* 173 * Destroy an inactive kthread. The kthread must be in the LSIDL state. 174 */ 175void 176kthread_destroy(lwp_t *l) 177{ 178 179 KASSERT((l->l_flag & LW_SYSTEM) != 0); 180 KASSERT(l->l_stat == LSIDL); 181 182 lwp_exit(l); 183} 184