kern_kthread.c revision 1.16.6.1
1 /* $NetBSD: kern_kthread.c,v 1.16.6.1 2007/04/09 22:10:02 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 1.16.6.1 2007/04/09 22:10:02 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/wait.h> 49 #include <sys/malloc.h> 50 #include <sys/queue.h> 51 52 #include <uvm/uvm_extern.h> 53 54 /* 55 * note that stdarg.h and the ansi style va_start macro is used for both 56 * ansi and traditional c complers. 57 * XXX: this requires that stdarg.h define: va_alist and va_dcl 58 */ 59 #include <machine/stdarg.h> 60 61 bool kthread_create_now; 62 63 /* 64 * Fork a kernel thread. Any process can request this to be done. 65 * The VM space and limits, etc. will be shared with proc0. 66 */ 67 int 68 kthread_create1(pri_t pri, bool mpsafe, void (*func)(void *), void *arg, 69 struct lwp **lp, const char *fmt, ...) 70 { 71 struct lwp *l; 72 vaddr_t uaddr; 73 bool inmem; 74 int error; 75 va_list ap; 76 77 inmem = uvm_uarea_alloc(&uaddr); 78 if (uaddr == 0) 79 return ENOMEM; 80 error = newlwp(&lwp0, &proc0, uaddr, inmem, 0, NULL, 0, func, arg, &l); 81 if (error) { 82 /* XXX uvm_uarea_free(uaddr); */ 83 return error; 84 } 85 86 /* Set parameters. */ 87 if (pri == PRI_NONE) { 88 /* Minimum kernel priority level. */ 89 pri = PUSER - 1; 90 } 91 if (mpsafe) 92 l->l_pflag |= LP_MPSAFE; 93 if (fmt != NULL) { 94 va_start(ap, fmt); 95 vsnprintf(l->l_name, MAXCOMLEN, fmt, ap); 96 va_end(ap); 97 } 98 99 /* Set the new LWP running. */ 100 mutex_enter(&proc0.p_smutex); 101 lwp_lock(l); 102 l->l_usrpri = pri; 103 l->l_priority = pri; 104 l->l_stat = LSRUN; 105 proc0.p_nrlwps++; 106 setrunqueue(l); 107 lwp_unlock(l); 108 mutex_exit(&proc0.p_smutex); 109 110 /* All done! */ 111 if (lp != NULL) 112 *lp = l; 113 114 return (0); 115 } 116 117 /* 118 * Cause a kernel thread to exit. Assumes the exiting thread is the 119 * current context. 120 */ 121 void 122 kthread_exit(int ecode) 123 { 124 struct lwp *l = curlwp; 125 126 /* We can't do much with the exit code, so just report it. */ 127 if (ecode != 0) 128 printf("WARNING: kthread `%s' (%d) exits with status %d\n", 129 l->l_name, l->l_lid, ecode); 130 131 /* Acquire the sched state mutex. exit1() will release it. */ 132 lwp_exit(l); 133 134 /* 135 * XXX Fool the compiler. Making exit1() __noreturn__ is a can 136 * XXX of worms right now. 137 */ 138 for (;;); 139 } 140 141 struct kthread_q { 142 SIMPLEQ_ENTRY(kthread_q) kq_q; 143 void (*kq_func)(void *); 144 void *kq_arg; 145 }; 146 147 SIMPLEQ_HEAD(, kthread_q) kthread_q = SIMPLEQ_HEAD_INITIALIZER(kthread_q); 148 149 /* 150 * Defer the creation of a kernel thread. Once the standard kernel threads 151 * and processes have been created, this queue will be run to callback to 152 * the caller to create threads for e.g. file systems and device drivers. 153 */ 154 void 155 kthread_create(void (*func)(void *), void *arg) 156 { 157 struct kthread_q *kq; 158 159 if (kthread_create_now) { 160 (*func)(arg); 161 return; 162 } 163 164 kq = malloc(sizeof(*kq), M_TEMP, M_NOWAIT); 165 if (kq == NULL) 166 panic("unable to allocate kthread_q"); 167 memset(kq, 0, sizeof(*kq)); 168 169 kq->kq_func = func; 170 kq->kq_arg = arg; 171 172 SIMPLEQ_INSERT_TAIL(&kthread_q, kq, kq_q); 173 } 174 175 void 176 kthread_run_deferred_queue(void) 177 { 178 struct kthread_q *kq; 179 180 /* No longer need to defer kthread creation. */ 181 kthread_create_now = true; 182 183 while ((kq = SIMPLEQ_FIRST(&kthread_q)) != NULL) { 184 SIMPLEQ_REMOVE_HEAD(&kthread_q, kq_q); 185 (*kq->kq_func)(kq->kq_arg); 186 free(kq, M_TEMP); 187 } 188 } 189
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