1 /* 2 * Copyright (c) 2005 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Sergey Glushchenko <deen@smz.com.ua> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/sys/kern/kern_usched.c,v 1.9 2007/07/02 17:06:55 dillon Exp $ 35 */ 36 37 #include <sys/errno.h> 38 #include <sys/globaldata.h> /* curthread */ 39 #include <sys/proc.h> 40 #include <sys/priv.h> 41 #include <sys/sysproto.h> /* struct usched_set_args */ 42 #include <sys/systm.h> /* strcmp() */ 43 #include <sys/usched.h> 44 #include <machine/smp.h> 45 46 static TAILQ_HEAD(, usched) usched_list = TAILQ_HEAD_INITIALIZER(usched_list); 47 48 cpumask_t usched_mastermask = -1; 49 50 /* 51 * Called from very low level boot code, i386/i386/machdep.c/init386(). 52 * We cannot do anything fancy. no malloc's, no nothing other then 53 * static initialization. 54 */ 55 struct usched * 56 usched_init(void) 57 { 58 const char *defsched; 59 60 defsched = kgetenv("kern.user_scheduler"); 61 62 /* 63 * Add various userland schedulers to the system. 64 */ 65 usched_ctl(&usched_bsd4, USCH_ADD); 66 usched_ctl(&usched_dummy, USCH_ADD); 67 if (defsched == NULL ) 68 return(&usched_bsd4); 69 if (strcmp(defsched, "bsd4") == 0) 70 return(&usched_bsd4); 71 kprintf("WARNING: Running dummy userland scheduler\n"); 72 return(&usched_dummy); 73 } 74 75 /* 76 * USCHED_CTL 77 * 78 * SYNOPSIS: 79 * Add/remove usched to/from list. 80 * 81 * ARGUMENTS: 82 * usched - pointer to target scheduler 83 * action - addition or removal ? 84 * 85 * RETURN VALUES: 86 * 0 - success 87 * EINVAL - error 88 */ 89 int 90 usched_ctl(struct usched *usched, int action) 91 { 92 struct usched *item; /* temporaly for TAILQ processing */ 93 int error = 0; 94 95 switch(action) { 96 case USCH_ADD: 97 /* 98 * Make sure it isn't already on the list 99 */ 100 #ifdef INVARIANTS 101 TAILQ_FOREACH(item, &usched_list, entry) { 102 KKASSERT(item != usched); 103 } 104 #endif 105 /* 106 * Optional callback to the scheduler before we officially 107 * add it to the list. 108 */ 109 if (usched->usched_register) 110 usched->usched_register(); 111 TAILQ_INSERT_TAIL(&usched_list, usched, entry); 112 break; 113 case USCH_REM: 114 /* 115 * Do not allow the default scheduler to be removed 116 */ 117 if (strcmp(usched->name, "bsd4") == 0) { 118 error = EINVAL; 119 break; 120 } 121 TAILQ_FOREACH(item, &usched_list, entry) { 122 if (item == usched) 123 break; 124 } 125 if (item) { 126 if (item->usched_unregister) 127 item->usched_unregister(); 128 TAILQ_REMOVE(&usched_list, item, entry); 129 } else { 130 error = EINVAL; 131 } 132 break; 133 default: 134 error = EINVAL; 135 break; 136 } 137 return (error); 138 } 139 140 /* 141 * USCHED_SET(syscall) 142 * 143 * SYNOPSIS: 144 * Setting up a proc's usched. 145 * 146 * ARGUMENTS: 147 * pid - 148 * cmd - 149 * data - 150 * bytes - 151 * RETURN VALUES: 152 * 0 - success 153 * EINVAL - error 154 */ 155 int 156 sys_usched_set(struct usched_set_args *uap) 157 { 158 struct proc *p = curthread->td_proc; 159 struct usched *item; /* temporaly for TAILQ processing */ 160 int error; 161 char buffer[NAME_LENGTH]; 162 cpumask_t mask; 163 struct lwp *lp; 164 int cpuid; 165 /* USCHED_GET_CPU doesn't require root privileges. */ 166 if (uap->cmd != USCHED_GET_CPU && (error = priv_check(curthread, PRIV_ROOT)) != 0) 167 return (error); 168 169 if (uap->pid != 0 && uap->pid != curthread->td_proc->p_pid) 170 return (EINVAL); 171 172 lp = curthread->td_lwp; 173 switch (uap->cmd) { 174 case USCHED_SET_SCHEDULER: 175 if ((error = copyinstr(uap->data, buffer, sizeof(buffer), 176 NULL)) != 0) 177 return (error); 178 TAILQ_FOREACH(item, &usched_list, entry) { 179 if ((strcmp(item->name, buffer) == 0)) 180 break; 181 } 182 183 /* 184 * If the scheduler for a process is being changed, disassociate 185 * the old scheduler before switching to the new one. 186 * 187 * XXX we might have to add an additional ABI call to do a 'full 188 * disassociation' and another ABI call to do a 'full 189 * reassociation' 190 */ 191 /* XXX lwp have to deal with multiple lwps here */ 192 if (p->p_nthreads != 1) 193 return (EINVAL); 194 if (item && item != p->p_usched) { 195 /* XXX lwp */ 196 p->p_usched->release_curproc(ONLY_LWP_IN_PROC(p)); 197 p->p_usched = item; 198 } else if (item == NULL) { 199 error = EINVAL; 200 } 201 break; 202 case USCHED_SET_CPU: 203 if (uap->bytes != sizeof(int)) 204 return (EINVAL); 205 error = copyin(uap->data, &cpuid, sizeof(int)); 206 if (error) 207 break; 208 if (cpuid < 0 || cpuid >= ncpus) { 209 error = EFBIG; 210 break; 211 } 212 if ((smp_active_mask & (1 << cpuid)) == 0) { 213 error = EINVAL; 214 break; 215 } 216 lp->lwp_cpumask = 1 << cpuid; 217 if (cpuid != mycpu->gd_cpuid) 218 lwkt_migratecpu(cpuid); 219 break; 220 case USCHED_GET_CPU: 221 if (uap->bytes != sizeof(int)) 222 return (EINVAL); 223 error = copyout(&(mycpu->gd_cpuid), uap->data, sizeof(int)); 224 break; 225 case USCHED_ADD_CPU: 226 if (uap->bytes != sizeof(int)) 227 return (EINVAL); 228 error = copyin(uap->data, &cpuid, sizeof(int)); 229 if (error) 230 break; 231 if (cpuid < 0 || cpuid >= ncpus) { 232 error = EFBIG; 233 break; 234 } 235 if (!(smp_active_mask & (1 << cpuid))) { 236 error = EINVAL; 237 break; 238 } 239 lp->lwp_cpumask |= 1 << cpuid; 240 break; 241 case USCHED_DEL_CPU: 242 if (uap->bytes != sizeof(int)) 243 return (EINVAL); 244 error = copyin(uap->data, &cpuid, sizeof(int)); 245 if (error) 246 break; 247 if (cpuid < 0 || cpuid >= ncpus) { 248 error = EFBIG; 249 break; 250 } 251 lp = curthread->td_lwp; 252 mask = lp->lwp_cpumask & smp_active_mask & ~(1 << cpuid); 253 if (mask == 0) 254 error = EPERM; 255 else { 256 lp->lwp_cpumask &= ~(1 << cpuid); 257 if ((lp->lwp_cpumask & mycpu->gd_cpumask) == 0) { 258 cpuid = bsfl(lp->lwp_cpumask & smp_active_mask); 259 lwkt_migratecpu(cpuid); 260 } 261 } 262 default: 263 error = EINVAL; 264 break; 265 } 266 return (error); 267 } 268 269