sys_pset.c revision 1.9
1 /* $NetBSD: sys_pset.c,v 1.9 2008/09/30 16:28:45 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 * Implementation of the Processor Sets. 31 * 32 * Locking 33 * The array of the processor-set structures and its members are protected 34 * by the global cpu_lock. Note that in scheduler, the very l_psid value 35 * might be used without lock held. 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: sys_pset.c,v 1.9 2008/09/30 16:28:45 rmind Exp $"); 40 41 #include <sys/param.h> 42 43 #include <sys/cpu.h> 44 #include <sys/kauth.h> 45 #include <sys/kmem.h> 46 #include <sys/lwp.h> 47 #include <sys/mutex.h> 48 #include <sys/proc.h> 49 #include <sys/pset.h> 50 #include <sys/sched.h> 51 #include <sys/syscallargs.h> 52 #include <sys/sysctl.h> 53 #include <sys/systm.h> 54 #include <sys/types.h> 55 56 static pset_info_t ** psets; 57 static u_int psets_max; 58 static u_int psets_count; 59 60 static int psets_realloc(int); 61 static int psid_validate(psetid_t, bool); 62 static int kern_pset_create(psetid_t *); 63 static int kern_pset_destroy(psetid_t); 64 65 /* 66 * Initialization of the processor-sets. 67 */ 68 void 69 psets_init(void) 70 { 71 72 psets_max = max(MAXCPUS, 32); 73 psets = kmem_zalloc(psets_max * sizeof(void *), KM_SLEEP); 74 psets_count = 0; 75 } 76 77 /* 78 * Reallocate the array of the processor-set structures. 79 */ 80 static int 81 psets_realloc(int new_psets_max) 82 { 83 pset_info_t **new_psets, **old_psets; 84 const u_int newsize = new_psets_max * sizeof(void *); 85 u_int i, oldsize; 86 87 if (new_psets_max < 1) 88 return EINVAL; 89 90 new_psets = kmem_zalloc(newsize, KM_SLEEP); 91 mutex_enter(&cpu_lock); 92 old_psets = psets; 93 oldsize = psets_max * sizeof(void *); 94 95 /* Check if we can lower the size of the array */ 96 if (new_psets_max < psets_max) { 97 for (i = new_psets_max; i < psets_max; i++) { 98 if (psets[i] == NULL) 99 continue; 100 mutex_exit(&cpu_lock); 101 kmem_free(new_psets, newsize); 102 return EBUSY; 103 } 104 } 105 106 /* Copy all pointers to the new array */ 107 memcpy(new_psets, psets, newsize); 108 psets_max = new_psets_max; 109 psets = new_psets; 110 mutex_exit(&cpu_lock); 111 112 kmem_free(old_psets, oldsize); 113 return 0; 114 } 115 116 /* 117 * Validate processor-set ID. 118 */ 119 static int 120 psid_validate(psetid_t psid, bool chkps) 121 { 122 123 KASSERT(mutex_owned(&cpu_lock)); 124 125 if (chkps && (psid == PS_NONE || psid == PS_QUERY || psid == PS_MYID)) 126 return 0; 127 if (psid <= 0 || psid > psets_max) 128 return EINVAL; 129 if (psets[psid - 1] == NULL) 130 return EINVAL; 131 if (psets[psid - 1]->ps_flags & PSET_BUSY) 132 return EBUSY; 133 134 return 0; 135 } 136 137 /* 138 * Create a processor-set. 139 */ 140 static int 141 kern_pset_create(psetid_t *psid) 142 { 143 pset_info_t *pi; 144 u_int i; 145 146 if (psets_count == psets_max) 147 return ENOMEM; 148 149 pi = kmem_zalloc(sizeof(pset_info_t), KM_SLEEP); 150 151 mutex_enter(&cpu_lock); 152 if (psets_count == psets_max) { 153 mutex_exit(&cpu_lock); 154 kmem_free(pi, sizeof(pset_info_t)); 155 return ENOMEM; 156 } 157 158 /* Find a free entry in the array */ 159 for (i = 0; i < psets_max; i++) 160 if (psets[i] == NULL) 161 break; 162 KASSERT(i != psets_max); 163 164 psets[i] = pi; 165 psets_count++; 166 mutex_exit(&cpu_lock); 167 168 *psid = i + 1; 169 return 0; 170 } 171 172 /* 173 * Destroy a processor-set. 174 */ 175 static int 176 kern_pset_destroy(psetid_t psid) 177 { 178 struct cpu_info *ci; 179 pset_info_t *pi; 180 struct lwp *l; 181 CPU_INFO_ITERATOR cii; 182 int error; 183 184 mutex_enter(&cpu_lock); 185 if (psid == PS_MYID) { 186 /* Use caller's processor-set ID */ 187 psid = curlwp->l_psid; 188 } 189 error = psid_validate(psid, false); 190 if (error) { 191 mutex_exit(&cpu_lock); 192 return error; 193 } 194 195 /* Release the processor-set from all CPUs */ 196 for (CPU_INFO_FOREACH(cii, ci)) { 197 struct schedstate_percpu *spc; 198 199 spc = &ci->ci_schedstate; 200 if (spc->spc_psid != psid) 201 continue; 202 spc->spc_psid = PS_NONE; 203 } 204 /* Mark that processor-set is going to be destroyed */ 205 pi = psets[psid - 1]; 206 pi->ps_flags |= PSET_BUSY; 207 mutex_exit(&cpu_lock); 208 209 /* Unmark the processor-set ID from each thread */ 210 mutex_enter(proc_lock); 211 LIST_FOREACH(l, &alllwp, l_list) { 212 /* Safe to check and set without lock held */ 213 if (l->l_psid != psid) 214 continue; 215 l->l_psid = PS_NONE; 216 } 217 mutex_exit(proc_lock); 218 219 /* Destroy the processor-set */ 220 mutex_enter(&cpu_lock); 221 psets[psid - 1] = NULL; 222 psets_count--; 223 mutex_exit(&cpu_lock); 224 225 kmem_free(pi, sizeof(pset_info_t)); 226 return 0; 227 } 228 229 /* 230 * General system calls for the processor-sets. 231 */ 232 233 int 234 sys_pset_create(struct lwp *l, const struct sys_pset_create_args *uap, 235 register_t *retval) 236 { 237 /* { 238 syscallarg(psetid_t) *psid; 239 } */ 240 psetid_t psid; 241 int error; 242 243 /* Available only for super-user */ 244 if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_PSET, 245 KAUTH_REQ_SYSTEM_PSET_CREATE, NULL, NULL, NULL)) 246 return EPERM; 247 248 error = kern_pset_create(&psid); 249 if (error) 250 return error; 251 252 error = copyout(&psid, SCARG(uap, psid), sizeof(psetid_t)); 253 if (error) 254 (void)kern_pset_destroy(psid); 255 256 return error; 257 } 258 259 int 260 sys_pset_destroy(struct lwp *l, const struct sys_pset_destroy_args *uap, 261 register_t *retval) 262 { 263 /* { 264 syscallarg(psetid_t) psid; 265 } */ 266 267 /* Available only for super-user */ 268 if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_PSET, 269 KAUTH_REQ_SYSTEM_PSET_DESTROY, 270 KAUTH_ARG(SCARG(uap, psid)), NULL, NULL)) 271 return EPERM; 272 273 return kern_pset_destroy(SCARG(uap, psid)); 274 } 275 276 int 277 sys_pset_assign(struct lwp *l, const struct sys_pset_assign_args *uap, 278 register_t *retval) 279 { 280 /* { 281 syscallarg(psetid_t) psid; 282 syscallarg(cpuid_t) cpuid; 283 syscallarg(psetid_t) *opsid; 284 } */ 285 struct cpu_info *ci; 286 struct schedstate_percpu *spc = NULL; 287 psetid_t psid = SCARG(uap, psid), opsid = 0; 288 CPU_INFO_ITERATOR cii; 289 int error = 0, nnone = 0; 290 291 /* Available only for super-user, except the case of PS_QUERY */ 292 if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_PSET, 293 KAUTH_REQ_SYSTEM_PSET_ASSIGN, KAUTH_ARG(SCARG(uap, psid)), NULL, 294 NULL)) 295 return EPERM; 296 297 /* Find the target CPU */ 298 mutex_enter(&cpu_lock); 299 for (CPU_INFO_FOREACH(cii, ci)) { 300 if (cpu_index(ci) == SCARG(uap, cpuid)) 301 spc = &ci->ci_schedstate; 302 nnone += (ci->ci_schedstate.spc_psid == PS_NONE); 303 } 304 if (spc == NULL) { 305 mutex_exit(&cpu_lock); 306 return EINVAL; 307 } 308 error = psid_validate(psid, true); 309 if (error) { 310 mutex_exit(&cpu_lock); 311 return error; 312 } 313 opsid = spc->spc_psid; 314 switch (psid) { 315 case PS_QUERY: 316 break; 317 case PS_MYID: 318 psid = curlwp->l_psid; 319 /* FALLTHROUGH */ 320 default: 321 /* 322 * Ensure at least one CPU stays in the default set, 323 * and that specified CPU is not offline. 324 */ 325 if (psid != PS_NONE && ((spc->spc_flags & SPCF_OFFLINE) || 326 (nnone == 1 && spc->spc_psid == PS_NONE))) { 327 mutex_exit(&cpu_lock); 328 return EBUSY; 329 } 330 spc->spc_psid = psid; 331 break; 332 } 333 mutex_exit(&cpu_lock); 334 335 if (SCARG(uap, opsid) != NULL) 336 error = copyout(&opsid, SCARG(uap, opsid), sizeof(psetid_t)); 337 338 return error; 339 } 340 341 int 342 sys__pset_bind(struct lwp *l, const struct sys__pset_bind_args *uap, 343 register_t *retval) 344 { 345 /* { 346 syscallarg(idtype_t) idtype; 347 syscallarg(id_t) first_id; 348 syscallarg(id_t) second_id; 349 syscallarg(psetid_t) psid; 350 syscallarg(psetid_t) *opsid; 351 } */ 352 struct cpu_info *ci; 353 struct proc *p; 354 struct lwp *t; 355 id_t id1, id2; 356 pid_t pid = 0; 357 lwpid_t lid = 0; 358 psetid_t psid, opsid; 359 int error = 0, lcnt; 360 361 psid = SCARG(uap, psid); 362 363 /* Available only for super-user, except the case of PS_QUERY */ 364 if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_PSET, 365 KAUTH_REQ_SYSTEM_PSET_BIND, KAUTH_ARG(SCARG(uap, psid)), NULL, 366 NULL)) 367 return EPERM; 368 369 mutex_enter(&cpu_lock); 370 error = psid_validate(psid, true); 371 if (error) { 372 mutex_exit(&cpu_lock); 373 return error; 374 } 375 if (psid == PS_MYID) 376 psid = curlwp->l_psid; 377 if (psid != PS_QUERY && psid != PS_NONE) 378 psets[psid - 1]->ps_flags |= PSET_BUSY; 379 mutex_exit(&cpu_lock); 380 381 /* 382 * Get PID and LID from the ID. 383 */ 384 p = l->l_proc; 385 id1 = SCARG(uap, first_id); 386 id2 = SCARG(uap, second_id); 387 388 switch (SCARG(uap, idtype)) { 389 case P_PID: 390 /* 391 * Process: 392 * First ID - PID; 393 * Second ID - ignored; 394 */ 395 pid = (id1 == P_MYID) ? p->p_pid : id1; 396 lid = 0; 397 break; 398 case P_LWPID: 399 /* 400 * Thread (LWP): 401 * First ID - LID; 402 * Second ID - PID; 403 */ 404 if (id1 == P_MYID) { 405 pid = p->p_pid; 406 lid = l->l_lid; 407 break; 408 } 409 lid = id1; 410 pid = (id2 == P_MYID) ? p->p_pid : id2; 411 break; 412 default: 413 error = EINVAL; 414 goto error; 415 } 416 417 /* Find the process */ 418 mutex_enter(proc_lock); 419 p = p_find(pid, PFIND_LOCKED); 420 if (p == NULL) { 421 mutex_exit(proc_lock); 422 error = ESRCH; 423 goto error; 424 } 425 mutex_enter(p->p_lock); 426 mutex_exit(proc_lock); 427 428 /* Disallow modification of the system processes */ 429 if (p->p_flag & PK_SYSTEM) { 430 mutex_exit(p->p_lock); 431 error = EPERM; 432 goto error; 433 } 434 435 /* Find the LWP(s) */ 436 lcnt = 0; 437 ci = NULL; 438 LIST_FOREACH(t, &p->p_lwps, l_sibling) { 439 if (lid && lid != t->l_lid) 440 continue; 441 /* 442 * Bind the thread to the processor-set, 443 * take some CPU and migrate. 444 */ 445 lwp_lock(t); 446 opsid = t->l_psid; 447 t->l_psid = psid; 448 ci = sched_takecpu(l); 449 /* Unlocks LWP */ 450 lwp_migrate(t, ci); 451 lcnt++; 452 } 453 mutex_exit(p->p_lock); 454 if (lcnt == 0) { 455 error = ESRCH; 456 goto error; 457 } 458 if (SCARG(uap, opsid)) 459 error = copyout(&opsid, SCARG(uap, opsid), sizeof(psetid_t)); 460 error: 461 if (psid != PS_QUERY && psid != PS_NONE) { 462 mutex_enter(&cpu_lock); 463 psets[psid - 1]->ps_flags &= ~PSET_BUSY; 464 mutex_exit(&cpu_lock); 465 } 466 return error; 467 } 468 469 /* 470 * Sysctl nodes and initialization. 471 */ 472 473 static int 474 sysctl_psets_max(SYSCTLFN_ARGS) 475 { 476 struct sysctlnode node; 477 int error, newsize; 478 479 node = *rnode; 480 node.sysctl_data = &newsize; 481 482 newsize = psets_max; 483 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 484 if (error || newp == NULL) 485 return error; 486 487 if (newsize <= 0) 488 return EINVAL; 489 490 sysctl_unlock(); 491 error = psets_realloc(newsize); 492 sysctl_relock(); 493 return error; 494 } 495 496 static int 497 sysctl_psets_list(SYSCTLFN_ARGS) 498 { 499 const size_t bufsz = 1024; 500 char *buf, tbuf[16]; 501 int i, error; 502 size_t len; 503 504 sysctl_unlock(); 505 buf = kmem_alloc(bufsz, KM_SLEEP); 506 snprintf(buf, bufsz, "%d:1", PS_NONE); /* XXX */ 507 508 mutex_enter(&cpu_lock); 509 for (i = 0; i < psets_max; i++) { 510 if (psets[i] == NULL) 511 continue; 512 snprintf(tbuf, sizeof(tbuf), ",%d:2", i + 1); /* XXX */ 513 strlcat(buf, tbuf, bufsz); 514 } 515 mutex_exit(&cpu_lock); 516 len = strlen(buf) + 1; 517 error = 0; 518 if (oldp != NULL) 519 error = copyout(buf, oldp, min(len, *oldlenp)); 520 *oldlenp = len; 521 kmem_free(buf, bufsz); 522 sysctl_relock(); 523 return error; 524 } 525 526 SYSCTL_SETUP(sysctl_pset_setup, "sysctl kern.pset subtree setup") 527 { 528 const struct sysctlnode *node = NULL; 529 530 sysctl_createv(clog, 0, NULL, NULL, 531 CTLFLAG_PERMANENT, 532 CTLTYPE_NODE, "kern", NULL, 533 NULL, 0, NULL, 0, 534 CTL_KERN, CTL_EOL); 535 sysctl_createv(clog, 0, NULL, &node, 536 CTLFLAG_PERMANENT, 537 CTLTYPE_NODE, "pset", 538 SYSCTL_DESCR("Processor-set options"), 539 NULL, 0, NULL, 0, 540 CTL_KERN, CTL_CREATE, CTL_EOL); 541 542 if (node == NULL) 543 return; 544 545 sysctl_createv(clog, 0, &node, NULL, 546 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 547 CTLTYPE_INT, "psets_max", 548 SYSCTL_DESCR("Maximal count of the processor-sets"), 549 sysctl_psets_max, 0, &psets_max, 0, 550 CTL_CREATE, CTL_EOL); 551 sysctl_createv(clog, 0, &node, NULL, 552 CTLFLAG_PERMANENT, 553 CTLTYPE_STRING, "list", 554 SYSCTL_DESCR("List of active sets"), 555 sysctl_psets_list, 0, NULL, 0, 556 CTL_CREATE, CTL_EOL); 557 } 558
Indexes created Tue Sep 23 07:09:52 GMT 2025