sys_sched.c revision 1.16
1 /* $NetBSD: sys_sched.c,v 1.16 2008/02/22 22:32:49 rmind Exp $ */ 2 3 /* 4 * Copyright (c) 2008, Mindaugas Rasiukevicius <rmind at NetBSD org> 5 * All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * TODO: 31 * - Handle pthread_setschedprio() as defined by POSIX; 32 * - Handle sched_yield() case for SCHED_FIFO as defined by POSIX; 33 */ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: sys_sched.c,v 1.16 2008/02/22 22:32:49 rmind Exp $"); 37 38 #include <sys/param.h> 39 40 #include <sys/cpu.h> 41 #include <sys/kauth.h> 42 #include <sys/kmem.h> 43 #include <sys/lwp.h> 44 #include <sys/mutex.h> 45 #include <sys/proc.h> 46 #include <sys/pset.h> 47 #include <sys/sched.h> 48 #include <sys/syscallargs.h> 49 #include <sys/sysctl.h> 50 #include <sys/systm.h> 51 #include <sys/types.h> 52 #include <sys/unistd.h> 53 54 /* 55 * Convert user priority or the in-kernel priority or convert the current 56 * priority to the appropriate range according to the policy change. 57 */ 58 static pri_t 59 convert_pri(lwp_t *l, int policy, pri_t pri) 60 { 61 int delta = 0; 62 63 switch (policy) { 64 case SCHED_OTHER: 65 delta = PRI_USER; 66 break; 67 case SCHED_FIFO: 68 case SCHED_RR: 69 delta = PRI_USER_RT; 70 break; 71 default: 72 panic("upri_to_kpri"); 73 } 74 75 if (pri != PRI_NONE) { 76 /* Convert user priority to the in-kernel */ 77 KASSERT(pri >= SCHED_PRI_MIN && pri <= SCHED_PRI_MAX); 78 return pri + delta; 79 } 80 if (l->l_class == policy) 81 return l->l_priority; 82 83 /* Change the current priority to the appropriate range */ 84 if (l->l_class == SCHED_OTHER) { 85 KASSERT(policy == SCHED_FIFO || policy == SCHED_RR); 86 return l->l_priority + delta; 87 } 88 if (policy == SCHED_OTHER) { 89 KASSERT(l->l_class == SCHED_FIFO || l->l_class == SCHED_RR); 90 return l->l_priority - delta; 91 } 92 KASSERT(l->l_class != SCHED_OTHER && policy != SCHED_OTHER); 93 return l->l_class; 94 } 95 96 /* 97 * Set scheduling parameters. 98 */ 99 int 100 sys__sched_setparam(struct lwp *l, const struct sys__sched_setparam_args *uap, 101 register_t *retval) 102 { 103 /* { 104 syscallarg(pid_t) pid; 105 syscallarg(lwpid_t) lid; 106 syscallarg(int) policy; 107 syscallarg(const struct sched_param *) params; 108 } */ 109 struct sched_param param; 110 struct proc *p; 111 struct lwp *t; 112 lwpid_t lid; 113 u_int lcnt; 114 int policy; 115 pri_t pri; 116 int error; 117 118 /* Get the parameters from the user-space */ 119 error = copyin(SCARG(uap, params), ¶m, sizeof(param)); 120 if (error) { 121 return error; 122 } 123 pri = param.sched_priority; 124 policy = SCARG(uap, policy); 125 126 /* If no parameters specified, just return (this should not happen) */ 127 if (pri == PRI_NONE && policy == SCHED_NONE) 128 return 0; 129 130 /* Validate scheduling class */ 131 if (policy != SCHED_NONE && (policy < SCHED_OTHER || policy > SCHED_RR)) 132 return EINVAL; 133 134 /* Validate priority */ 135 if (pri != PRI_NONE && (pri < SCHED_PRI_MIN || pri > SCHED_PRI_MAX)) 136 return EINVAL; 137 138 if (SCARG(uap, pid) != 0) { 139 /* Find the process */ 140 p = p_find(SCARG(uap, pid), PFIND_UNLOCK_FAIL); 141 if (p == NULL) 142 return ESRCH; 143 mutex_enter(&p->p_smutex); 144 mutex_exit(&proclist_lock); 145 /* Disallow modification of system processes */ 146 if (p->p_flag & PK_SYSTEM) { 147 mutex_exit(&p->p_smutex); 148 return EPERM; 149 } 150 } else { 151 /* Use the calling process */ 152 p = l->l_proc; 153 mutex_enter(&p->p_smutex); 154 } 155 156 /* Find the LWP(s) */ 157 lcnt = 0; 158 lid = SCARG(uap, lid); 159 LIST_FOREACH(t, &p->p_lwps, l_sibling) { 160 pri_t kpri; 161 int lpolicy; 162 163 if (lid && lid != t->l_lid) 164 continue; 165 lcnt++; 166 KASSERT(pri != PRI_NONE || policy != SCHED_NONE); 167 lwp_lock(t); 168 169 if (policy == SCHED_NONE) 170 lpolicy = t->l_class; 171 else 172 lpolicy = policy; 173 174 /* 175 * Note that, priority may need to be changed to get into 176 * the correct priority range of the new scheduling class. 177 */ 178 kpri = convert_pri(t, lpolicy, pri); 179 180 /* Check the permission */ 181 error = kauth_authorize_process(l->l_cred, 182 KAUTH_PROCESS_SCHEDULER_SETPARAM, p, t, KAUTH_ARG(lpolicy), 183 KAUTH_ARG(kpri)); 184 if (error) { 185 lwp_unlock(t); 186 break; 187 } 188 189 /* Set the scheduling class */ 190 if (policy != SCHED_NONE) 191 t->l_class = policy; 192 193 /* Change the priority */ 194 if (t->l_priority != kpri) 195 lwp_changepri(t, kpri); 196 197 lwp_unlock(t); 198 } 199 mutex_exit(&p->p_smutex); 200 return (lcnt == 0) ? ESRCH : error; 201 } 202 203 /* 204 * Get scheduling parameters. 205 */ 206 int 207 sys__sched_getparam(struct lwp *l, const struct sys__sched_getparam_args *uap, 208 register_t *retval) 209 { 210 /* { 211 syscallarg(pid_t) pid; 212 syscallarg(lwpid_t) lid; 213 syscallarg(int *) policy; 214 syscallarg(struct sched_param *) params; 215 } */ 216 struct sched_param param; 217 struct lwp *t; 218 int error, policy; 219 220 /* Locks the LWP */ 221 t = lwp_find2(SCARG(uap, pid), SCARG(uap, lid)); 222 if (t == NULL) 223 return ESRCH; 224 225 /* Check the permission */ 226 error = kauth_authorize_process(l->l_cred, 227 KAUTH_PROCESS_SCHEDULER_GETPARAM, t->l_proc, NULL, NULL, NULL); 228 if (error != 0) { 229 lwp_unlock(t); 230 return error; 231 } 232 233 param.sched_priority = t->l_priority; 234 policy = t->l_class; 235 lwp_unlock(t); 236 237 switch (policy) { 238 case SCHED_OTHER: 239 param.sched_priority -= PRI_USER; 240 break; 241 case SCHED_RR: 242 case SCHED_FIFO: 243 param.sched_priority -= PRI_USER_RT; 244 break; 245 } 246 error = copyout(¶m, SCARG(uap, params), sizeof(param)); 247 if (error == 0 && SCARG(uap, policy) != NULL) 248 error = copyout(&policy, SCARG(uap, policy), sizeof(int)); 249 return error; 250 } 251 252 /* 253 * Set affinity. 254 */ 255 int 256 sys__sched_setaffinity(struct lwp *l, 257 const struct sys__sched_setaffinity_args *uap, register_t *retval) 258 { 259 /* { 260 syscallarg(pid_t) pid; 261 syscallarg(lwpid_t) lid; 262 syscallarg(size_t) size; 263 syscallarg(void *) cpuset; 264 } */ 265 cpuset_t *cpuset; 266 struct cpu_info *ci = NULL; 267 struct proc *p; 268 struct lwp *t; 269 CPU_INFO_ITERATOR cii; 270 lwpid_t lid; 271 u_int lcnt; 272 int error; 273 274 /* Allocate the CPU set, and get it from userspace */ 275 cpuset = kmem_zalloc(sizeof(cpuset_t), KM_SLEEP); 276 error = copyin(SCARG(uap, cpuset), cpuset, 277 min(SCARG(uap, size), sizeof(cpuset_t))); 278 if (error) 279 goto error; 280 281 /* Look for a CPU in the set */ 282 for (CPU_INFO_FOREACH(cii, ci)) 283 if (CPU_ISSET(cpu_index(ci), cpuset)) 284 break; 285 if (ci == NULL) { 286 /* Empty set */ 287 kmem_free(cpuset, sizeof(cpuset_t)); 288 cpuset = NULL; 289 } 290 291 if (SCARG(uap, pid) != 0) { 292 /* Find the process */ 293 p = p_find(SCARG(uap, pid), PFIND_UNLOCK_FAIL); 294 if (p == NULL) { 295 error = ESRCH; 296 goto error; 297 } 298 mutex_enter(&p->p_smutex); 299 mutex_exit(&proclist_lock); 300 } else { 301 /* Use the calling process */ 302 p = l->l_proc; 303 mutex_enter(&p->p_smutex); 304 } 305 306 /* 307 * Check the permission. 308 * Disallow modification of system processes. 309 */ 310 error = kauth_authorize_process(l->l_cred, 311 KAUTH_PROCESS_SCHEDULER_SETAFFINITY, p, NULL, NULL, NULL); 312 if (error != 0) { 313 mutex_exit(&p->p_smutex); 314 goto error; 315 } 316 if ((p->p_flag & PK_SYSTEM) != 0) { 317 mutex_exit(&p->p_smutex); 318 error = EPERM; 319 goto error; 320 } 321 322 /* Find the LWP(s) */ 323 lcnt = 0; 324 lid = SCARG(uap, lid); 325 LIST_FOREACH(t, &p->p_lwps, l_sibling) { 326 if (lid && lid != t->l_lid) 327 continue; 328 lwp_lock(t); 329 if (cpuset) { 330 /* Set the affinity flag and new CPU set */ 331 t->l_flag |= LW_AFFINITY; 332 memcpy(&t->l_affinity, cpuset, sizeof(cpuset_t)); 333 /* Migrate to another CPU, unlocks LWP */ 334 lwp_migrate(t, ci); 335 } else { 336 /* Unset the affinity flag */ 337 t->l_flag &= ~LW_AFFINITY; 338 lwp_unlock(t); 339 } 340 lcnt++; 341 } 342 mutex_exit(&p->p_smutex); 343 if (lcnt == 0) 344 error = ESRCH; 345 error: 346 if (cpuset != NULL) 347 kmem_free(cpuset, sizeof(cpuset_t)); 348 return error; 349 } 350 351 /* 352 * Get affinity. 353 */ 354 int 355 sys__sched_getaffinity(struct lwp *l, 356 const struct sys__sched_getaffinity_args *uap, register_t *retval) 357 { 358 /* { 359 syscallarg(pid_t) pid; 360 syscallarg(lwpid_t) lid; 361 syscallarg(size_t) size; 362 syscallarg(void *) cpuset; 363 } */ 364 struct lwp *t; 365 void *cpuset; 366 int error; 367 368 if (SCARG(uap, size) <= 0) 369 return EINVAL; 370 cpuset = kmem_zalloc(sizeof(cpuset_t), KM_SLEEP); 371 372 /* Locks the LWP */ 373 t = lwp_find2(SCARG(uap, pid), SCARG(uap, lid)); 374 if (t == NULL) { 375 kmem_free(cpuset, sizeof(cpuset_t)); 376 return ESRCH; 377 } 378 /* Check the permission */ 379 if (kauth_authorize_process(l->l_cred, 380 KAUTH_PROCESS_SCHEDULER_GETAFFINITY, t->l_proc, NULL, NULL, NULL)) { 381 lwp_unlock(t); 382 kmem_free(cpuset, sizeof(cpuset_t)); 383 return EPERM; 384 } 385 if (t->l_flag & LW_AFFINITY) 386 memcpy(cpuset, &t->l_affinity, sizeof(cpuset_t)); 387 lwp_unlock(t); 388 389 error = copyout(cpuset, SCARG(uap, cpuset), 390 min(SCARG(uap, size), sizeof(cpuset_t))); 391 392 kmem_free(cpuset, sizeof(cpuset_t)); 393 return error; 394 } 395 396 /* 397 * Yield. 398 */ 399 int 400 sys_sched_yield(struct lwp *l, const void *v, register_t *retval) 401 { 402 403 yield(); 404 return 0; 405 } 406 407 /* 408 * Sysctl nodes and initialization. 409 */ 410 SYSCTL_SETUP(sysctl_sched_setup, "sysctl sched setup") 411 { 412 const struct sysctlnode *node = NULL; 413 414 sysctl_createv(clog, 0, NULL, NULL, 415 CTLFLAG_PERMANENT, 416 CTLTYPE_NODE, "kern", NULL, 417 NULL, 0, NULL, 0, 418 CTL_KERN, CTL_EOL); 419 sysctl_createv(clog, 0, NULL, NULL, 420 CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, 421 CTLTYPE_INT, "posix_sched", 422 SYSCTL_DESCR("Version of IEEE Std 1003.1 and its " 423 "Process Scheduling option to which the " 424 "system attempts to conform"), 425 NULL, _POSIX_PRIORITY_SCHEDULING, NULL, 0, 426 CTL_KERN, CTL_CREATE, CTL_EOL); 427 sysctl_createv(clog, 0, NULL, &node, 428 CTLFLAG_PERMANENT, 429 CTLTYPE_NODE, "sched", 430 SYSCTL_DESCR("Scheduler options"), 431 NULL, 0, NULL, 0, 432 CTL_KERN, CTL_CREATE, CTL_EOL); 433 434 if (node == NULL) 435 return; 436 437 sysctl_createv(clog, 0, &node, NULL, 438 CTLFLAG_PERMANENT | CTLFLAG_IMMEDIATE, 439 CTLTYPE_INT, "pri_min", 440 SYSCTL_DESCR("Minimal POSIX real-time priority"), 441 NULL, SCHED_PRI_MIN, NULL, 0, 442 CTL_CREATE, CTL_EOL); 443 sysctl_createv(clog, 0, &node, NULL, 444 CTLFLAG_PERMANENT | CTLFLAG_IMMEDIATE, 445 CTLTYPE_INT, "pri_max", 446 SYSCTL_DESCR("Minimal POSIX real-time priority"), 447 NULL, SCHED_PRI_MAX, NULL, 0, 448 CTL_CREATE, CTL_EOL); 449 } 450
Indexes created Sat Sep 27 14:09:57 GMT 2025