sys_pset.c revision 1.10
1 /* $NetBSD: sys_pset.c,v 1.10 2009/01/20 01:57:35 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 1.10 2009/01/20 01:57:35 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 *ici, *ci = NULL; 286 struct schedstate_percpu *spc = NULL; 287 struct lwp *t; 288 psetid_t psid = SCARG(uap, psid), opsid = 0; 289 CPU_INFO_ITERATOR cii; 290 int error = 0, nnone = 0; 291 292 /* Available only for super-user, except the case of PS_QUERY */ 293 if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_PSET, 294 KAUTH_REQ_SYSTEM_PSET_ASSIGN, KAUTH_ARG(SCARG(uap, psid)), NULL, 295 NULL)) 296 return EPERM; 297 298 /* Find the target CPU */ 299 mutex_enter(&cpu_lock); 300 for (CPU_INFO_FOREACH(cii, ici)) { 301 struct schedstate_percpu *ispc; 302 ispc = &ici->ci_schedstate; 303 if (cpu_index(ici) == SCARG(uap, cpuid)) { 304 ci = ici; 305 spc = ispc; 306 } 307 nnone += (ispc->spc_psid == PS_NONE); 308 } 309 if (ci == NULL) { 310 mutex_exit(&cpu_lock); 311 return EINVAL; 312 } 313 error = psid_validate(psid, true); 314 if (error) { 315 mutex_exit(&cpu_lock); 316 return error; 317 } 318 opsid = spc->spc_psid; 319 switch (psid) { 320 case PS_QUERY: 321 break; 322 case PS_MYID: 323 psid = curlwp->l_psid; 324 /* FALLTHROUGH */ 325 default: 326 /* 327 * Ensure at least one CPU stays in the default set, 328 * and that specified CPU is not offline. 329 */ 330 if (psid != PS_NONE && ((spc->spc_flags & SPCF_OFFLINE) || 331 (nnone == 1 && spc->spc_psid == PS_NONE))) { 332 mutex_exit(&cpu_lock); 333 return EBUSY; 334 } 335 mutex_enter(proc_lock); 336 /* 337 * Ensure that none of the threads are using affinity mask 338 * with this target CPU in it. 339 */ 340 LIST_FOREACH(t, &alllwp, l_list) { 341 if ((t->l_flag & LW_AFFINITY) == 0) 342 continue; 343 if (kcpuset_isset(cpu_index(ci), t->l_affinity)) { 344 mutex_exit(proc_lock); 345 mutex_exit(&cpu_lock); 346 return EPERM; 347 } 348 } 349 /* 350 * Set the processor-set ID. 351 * Migrate out any threads running on this CPU. 352 */ 353 spc->spc_psid = psid; 354 355 LIST_FOREACH(t, &alllwp, l_list) { 356 struct cpu_info *tci; 357 if (t->l_cpu != ci) 358 continue; 359 if (t->l_pflag & (LP_BOUND | LP_INTR)) 360 continue; 361 lwp_lock(t); 362 tci = sched_takecpu(t); 363 KASSERT(tci != ci); 364 lwp_migrate(t, tci); 365 } 366 mutex_exit(proc_lock); 367 break; 368 } 369 mutex_exit(&cpu_lock); 370 371 if (SCARG(uap, opsid) != NULL) 372 error = copyout(&opsid, SCARG(uap, opsid), sizeof(psetid_t)); 373 374 return error; 375 } 376 377 int 378 sys__pset_bind(struct lwp *l, const struct sys__pset_bind_args *uap, 379 register_t *retval) 380 { 381 /* { 382 syscallarg(idtype_t) idtype; 383 syscallarg(id_t) first_id; 384 syscallarg(id_t) second_id; 385 syscallarg(psetid_t) psid; 386 syscallarg(psetid_t) *opsid; 387 } */ 388 struct cpu_info *ci; 389 struct proc *p; 390 struct lwp *t; 391 id_t id1, id2; 392 pid_t pid = 0; 393 lwpid_t lid = 0; 394 psetid_t psid, opsid; 395 int error = 0, lcnt; 396 397 psid = SCARG(uap, psid); 398 399 /* Available only for super-user, except the case of PS_QUERY */ 400 if (kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_PSET, 401 KAUTH_REQ_SYSTEM_PSET_BIND, KAUTH_ARG(SCARG(uap, psid)), NULL, 402 NULL)) 403 return EPERM; 404 405 mutex_enter(&cpu_lock); 406 error = psid_validate(psid, true); 407 if (error) { 408 mutex_exit(&cpu_lock); 409 return error; 410 } 411 if (psid == PS_MYID) 412 psid = curlwp->l_psid; 413 if (psid != PS_QUERY && psid != PS_NONE) 414 psets[psid - 1]->ps_flags |= PSET_BUSY; 415 mutex_exit(&cpu_lock); 416 417 /* 418 * Get PID and LID from the ID. 419 */ 420 p = l->l_proc; 421 id1 = SCARG(uap, first_id); 422 id2 = SCARG(uap, second_id); 423 424 switch (SCARG(uap, idtype)) { 425 case P_PID: 426 /* 427 * Process: 428 * First ID - PID; 429 * Second ID - ignored; 430 */ 431 pid = (id1 == P_MYID) ? p->p_pid : id1; 432 lid = 0; 433 break; 434 case P_LWPID: 435 /* 436 * Thread (LWP): 437 * First ID - LID; 438 * Second ID - PID; 439 */ 440 if (id1 == P_MYID) { 441 pid = p->p_pid; 442 lid = l->l_lid; 443 break; 444 } 445 lid = id1; 446 pid = (id2 == P_MYID) ? p->p_pid : id2; 447 break; 448 default: 449 error = EINVAL; 450 goto error; 451 } 452 453 /* Find the process */ 454 mutex_enter(proc_lock); 455 p = p_find(pid, PFIND_LOCKED); 456 if (p == NULL) { 457 mutex_exit(proc_lock); 458 error = ESRCH; 459 goto error; 460 } 461 mutex_enter(p->p_lock); 462 mutex_exit(proc_lock); 463 464 /* Disallow modification of the system processes */ 465 if (p->p_flag & PK_SYSTEM) { 466 mutex_exit(p->p_lock); 467 error = EPERM; 468 goto error; 469 } 470 471 /* Find the LWP(s) */ 472 lcnt = 0; 473 ci = NULL; 474 LIST_FOREACH(t, &p->p_lwps, l_sibling) { 475 if (lid && lid != t->l_lid) 476 continue; 477 /* 478 * Bind the thread to the processor-set, 479 * take some CPU and migrate. 480 */ 481 lwp_lock(t); 482 opsid = t->l_psid; 483 t->l_psid = psid; 484 ci = sched_takecpu(l); 485 /* Unlocks LWP */ 486 lwp_migrate(t, ci); 487 lcnt++; 488 } 489 mutex_exit(p->p_lock); 490 if (lcnt == 0) { 491 error = ESRCH; 492 goto error; 493 } 494 if (SCARG(uap, opsid)) 495 error = copyout(&opsid, SCARG(uap, opsid), sizeof(psetid_t)); 496 error: 497 if (psid != PS_QUERY && psid != PS_NONE) { 498 mutex_enter(&cpu_lock); 499 psets[psid - 1]->ps_flags &= ~PSET_BUSY; 500 mutex_exit(&cpu_lock); 501 } 502 return error; 503 } 504 505 /* 506 * Sysctl nodes and initialization. 507 */ 508 509 static int 510 sysctl_psets_max(SYSCTLFN_ARGS) 511 { 512 struct sysctlnode node; 513 int error, newsize; 514 515 node = *rnode; 516 node.sysctl_data = &newsize; 517 518 newsize = psets_max; 519 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 520 if (error || newp == NULL) 521 return error; 522 523 if (newsize <= 0) 524 return EINVAL; 525 526 sysctl_unlock(); 527 error = psets_realloc(newsize); 528 sysctl_relock(); 529 return error; 530 } 531 532 static int 533 sysctl_psets_list(SYSCTLFN_ARGS) 534 { 535 const size_t bufsz = 1024; 536 char *buf, tbuf[16]; 537 int i, error; 538 size_t len; 539 540 sysctl_unlock(); 541 buf = kmem_alloc(bufsz, KM_SLEEP); 542 snprintf(buf, bufsz, "%d:1", PS_NONE); /* XXX */ 543 544 mutex_enter(&cpu_lock); 545 for (i = 0; i < psets_max; i++) { 546 if (psets[i] == NULL) 547 continue; 548 snprintf(tbuf, sizeof(tbuf), ",%d:2", i + 1); /* XXX */ 549 strlcat(buf, tbuf, bufsz); 550 } 551 mutex_exit(&cpu_lock); 552 len = strlen(buf) + 1; 553 error = 0; 554 if (oldp != NULL) 555 error = copyout(buf, oldp, min(len, *oldlenp)); 556 *oldlenp = len; 557 kmem_free(buf, bufsz); 558 sysctl_relock(); 559 return error; 560 } 561 562 SYSCTL_SETUP(sysctl_pset_setup, "sysctl kern.pset subtree setup") 563 { 564 const struct sysctlnode *node = NULL; 565 566 sysctl_createv(clog, 0, NULL, NULL, 567 CTLFLAG_PERMANENT, 568 CTLTYPE_NODE, "kern", NULL, 569 NULL, 0, NULL, 0, 570 CTL_KERN, CTL_EOL); 571 sysctl_createv(clog, 0, NULL, &node, 572 CTLFLAG_PERMANENT, 573 CTLTYPE_NODE, "pset", 574 SYSCTL_DESCR("Processor-set options"), 575 NULL, 0, NULL, 0, 576 CTL_KERN, CTL_CREATE, CTL_EOL); 577 578 if (node == NULL) 579 return; 580 581 sysctl_createv(clog, 0, &node, NULL, 582 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 583 CTLTYPE_INT, "psets_max", 584 SYSCTL_DESCR("Maximal count of the processor-sets"), 585 sysctl_psets_max, 0, &psets_max, 0, 586 CTL_CREATE, CTL_EOL); 587 sysctl_createv(clog, 0, &node, NULL, 588 CTLFLAG_PERMANENT, 589 CTLTYPE_STRING, "list", 590 SYSCTL_DESCR("List of active sets"), 591 sysctl_psets_list, 0, NULL, 0, 592 CTL_CREATE, CTL_EOL); 593 } 594
Indexes created Mon Sep 22 05:09:51 GMT 2025