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 45 #include <sys/mplock2.h> 46 47 #include <machine/smp.h> 48 49 static TAILQ_HEAD(, usched) usched_list = TAILQ_HEAD_INITIALIZER(usched_list); 50 51 cpumask_t usched_mastermask = -1; 52 53 /* 54 * Called from very low level boot code, i386/i386/machdep.c/init386(). 55 * We cannot do anything fancy. no malloc's, no nothing other then 56 * static initialization. 57 */ 58 struct usched * 59 usched_init(void) 60 { 61 const char *defsched; 62 63 defsched = kgetenv("kern.user_scheduler"); 64 65 /* 66 * Add various userland schedulers to the system. 67 */ 68 usched_ctl(&usched_bsd4, USCH_ADD); 69 usched_ctl(&usched_dummy, USCH_ADD); 70 if (defsched == NULL ) 71 return(&usched_bsd4); 72 if (strcmp(defsched, "bsd4") == 0) 73 return(&usched_bsd4); 74 kprintf("WARNING: Running dummy userland scheduler\n"); 75 return(&usched_dummy); 76 } 77 78 /* 79 * USCHED_CTL 80 * 81 * SYNOPSIS: 82 * Add/remove usched to/from list. 83 * 84 * ARGUMENTS: 85 * usched - pointer to target scheduler 86 * action - addition or removal ? 87 * 88 * RETURN VALUES: 89 * 0 - success 90 * EINVAL - error 91 */ 92 int 93 usched_ctl(struct usched *usched, int action) 94 { 95 struct usched *item; /* temporaly for TAILQ processing */ 96 int error = 0; 97 98 switch(action) { 99 case USCH_ADD: 100 /* 101 * Make sure it isn't already on the list 102 */ 103 #ifdef INVARIANTS 104 TAILQ_FOREACH(item, &usched_list, entry) { 105 KKASSERT(item != usched); 106 } 107 #endif 108 /* 109 * Optional callback to the scheduler before we officially 110 * add it to the list. 111 */ 112 if (usched->usched_register) 113 usched->usched_register(); 114 TAILQ_INSERT_TAIL(&usched_list, usched, entry); 115 break; 116 case USCH_REM: 117 /* 118 * Do not allow the default scheduler to be removed 119 */ 120 if (strcmp(usched->name, "bsd4") == 0) { 121 error = EINVAL; 122 break; 123 } 124 TAILQ_FOREACH(item, &usched_list, entry) { 125 if (item == usched) 126 break; 127 } 128 if (item) { 129 if (item->usched_unregister) 130 item->usched_unregister(); 131 TAILQ_REMOVE(&usched_list, item, entry); 132 } else { 133 error = EINVAL; 134 } 135 break; 136 default: 137 error = EINVAL; 138 break; 139 } 140 return (error); 141 } 142 143 /* 144 * USCHED_SET(syscall) 145 * 146 * SYNOPSIS: 147 * Setting up a proc's usched. 148 * 149 * ARGUMENTS: 150 * pid - 151 * cmd - 152 * data - 153 * bytes - 154 * RETURN VALUES: 155 * 0 - success 156 * EINVAL - error 157 * 158 * MPALMOSTSAFE 159 */ 160 int 161 sys_usched_set(struct usched_set_args *uap) 162 { 163 struct proc *p = curthread->td_proc; 164 struct usched *item; /* temporaly for TAILQ processing */ 165 int error; 166 char buffer[NAME_LENGTH]; 167 cpumask_t mask; 168 struct lwp *lp; 169 int cpuid; 170 171 if (uap->pid != 0 && uap->pid != curthread->td_proc->p_pid) 172 return (EINVAL); 173 174 lp = curthread->td_lwp; 175 get_mplock(); 176 177 switch (uap->cmd) { 178 case USCHED_SET_SCHEDULER: 179 if ((error = priv_check(curthread, PRIV_SCHED_SET)) != 0) 180 break; 181 error = copyinstr(uap->data, buffer, sizeof(buffer), NULL); 182 if (error) 183 break; 184 TAILQ_FOREACH(item, &usched_list, entry) { 185 if ((strcmp(item->name, buffer) == 0)) 186 break; 187 } 188 189 /* 190 * If the scheduler for a process is being changed, disassociate 191 * the old scheduler before switching to the new one. 192 * 193 * XXX we might have to add an additional ABI call to do a 'full 194 * disassociation' and another ABI call to do a 'full 195 * reassociation' 196 */ 197 /* XXX lwp have to deal with multiple lwps here */ 198 if (p->p_nthreads != 1) { 199 error = EINVAL; 200 break; 201 } 202 if (item && item != p->p_usched) { 203 /* XXX lwp */ 204 p->p_usched->release_curproc(ONLY_LWP_IN_PROC(p)); 205 p->p_usched = item; 206 } else if (item == NULL) { 207 error = EINVAL; 208 } 209 break; 210 case USCHED_SET_CPU: 211 if ((error = priv_check(curthread, PRIV_SCHED_CPUSET)) != 0) 212 break; 213 if (uap->bytes != sizeof(int)) { 214 error = EINVAL; 215 break; 216 } 217 error = copyin(uap->data, &cpuid, sizeof(int)); 218 if (error) 219 break; 220 if (cpuid < 0 || cpuid >= ncpus) { 221 error = EFBIG; 222 break; 223 } 224 if ((smp_active_mask & (1 << cpuid)) == 0) { 225 error = EINVAL; 226 break; 227 } 228 lp->lwp_cpumask = 1 << cpuid; 229 if (cpuid != mycpu->gd_cpuid) 230 lwkt_migratecpu(cpuid); 231 break; 232 case USCHED_GET_CPU: 233 /* USCHED_GET_CPU doesn't require special privileges. */ 234 if (uap->bytes != sizeof(int)) { 235 error = EINVAL; 236 break; 237 } 238 error = copyout(&(mycpu->gd_cpuid), uap->data, sizeof(int)); 239 break; 240 case USCHED_ADD_CPU: 241 if ((error = priv_check(curthread, PRIV_SCHED_CPUSET)) != 0) 242 break; 243 if (uap->bytes != sizeof(int)) { 244 error = EINVAL; 245 break; 246 } 247 error = copyin(uap->data, &cpuid, sizeof(int)); 248 if (error) 249 break; 250 if (cpuid < 0 || cpuid >= ncpus) { 251 error = EFBIG; 252 break; 253 } 254 if (!(smp_active_mask & (1 << cpuid))) { 255 error = EINVAL; 256 break; 257 } 258 lp->lwp_cpumask |= 1 << cpuid; 259 break; 260 case USCHED_DEL_CPU: 261 /* USCHED_DEL_CPU doesn't require special privileges. */ 262 if (uap->bytes != sizeof(int)) { 263 error = EINVAL; 264 break; 265 } 266 error = copyin(uap->data, &cpuid, sizeof(int)); 267 if (error) 268 break; 269 if (cpuid < 0 || cpuid >= ncpus) { 270 error = EFBIG; 271 break; 272 } 273 lp = curthread->td_lwp; 274 mask = lp->lwp_cpumask & smp_active_mask & ~(1 << cpuid); 275 if (mask == 0) 276 error = EPERM; 277 else { 278 lp->lwp_cpumask &= ~(1 << cpuid); 279 if ((lp->lwp_cpumask & mycpu->gd_cpumask) == 0) { 280 cpuid = bsfl(lp->lwp_cpumask & smp_active_mask); 281 lwkt_migratecpu(cpuid); 282 } 283 } 284 break; 285 default: 286 error = EINVAL; 287 break; 288 } 289 rel_mplock(); 290 return (error); 291 } 292 293