Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/kern/kern_cpuset.c
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1 /*- 2 * Copyright (c) 2008, Jeffrey Roberson <jeff@freebsd.org> 3 * All rights reserved. 4 * 5 * Copyright (c) 2008 Nokia Corporation 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD: releng/11.0/sys/kern/kern_cpuset.c 297748 2016-04-09 13:58:04Z jhb $"); 33 34 #include "opt_ddb.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/sysproto.h> 39 #include <sys/jail.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/malloc.h> 43 #include <sys/mutex.h> 44 #include <sys/priv.h> 45 #include <sys/proc.h> 46 #include <sys/refcount.h> 47 #include <sys/sched.h> 48 #include <sys/smp.h> 49 #include <sys/syscallsubr.h> 50 #include <sys/cpuset.h> 51 #include <sys/sx.h> 52 #include <sys/queue.h> 53 #include <sys/libkern.h> 54 #include <sys/limits.h> 55 #include <sys/bus.h> 56 #include <sys/interrupt.h> 57 58 #include <vm/uma.h> 59 #include <vm/vm.h> 60 #include <vm/vm_page.h> 61 #include <vm/vm_param.h> 62 #include <vm/vm_phys.h> 63 64 #ifdef DDB 65 #include <ddb/ddb.h> 66 #endif /* DDB */ 67 68 /* 69 * cpusets provide a mechanism for creating and manipulating sets of 70 * processors for the purpose of constraining the scheduling of threads to 71 * specific processors. 72 * 73 * Each process belongs to an identified set, by default this is set 1. Each 74 * thread may further restrict the cpus it may run on to a subset of this 75 * named set. This creates an anonymous set which other threads and processes 76 * may not join by number. 77 * 78 * The named set is referred to herein as the 'base' set to avoid ambiguity. 79 * This set is usually a child of a 'root' set while the anonymous set may 80 * simply be referred to as a mask. In the syscall api these are referred to 81 * as the ROOT, CPUSET, and MASK levels where CPUSET is called 'base' here. 82 * 83 * Threads inherit their set from their creator whether it be anonymous or 84 * not. This means that anonymous sets are immutable because they may be 85 * shared. To modify an anonymous set a new set is created with the desired 86 * mask and the same parent as the existing anonymous set. This gives the 87 * illusion of each thread having a private mask. 88 * 89 * Via the syscall apis a user may ask to retrieve or modify the root, base, 90 * or mask that is discovered via a pid, tid, or setid. Modifying a set 91 * modifies all numbered and anonymous child sets to comply with the new mask. 92 * Modifying a pid or tid's mask applies only to that tid but must still 93 * exist within the assigned parent set. 94 * 95 * A thread may not be assigned to a group separate from other threads in 96 * the process. This is to remove ambiguity when the setid is queried with 97 * a pid argument. There is no other technical limitation. 98 * 99 * This somewhat complex arrangement is intended to make it easy for 100 * applications to query available processors and bind their threads to 101 * specific processors while also allowing administrators to dynamically 102 * reprovision by changing sets which apply to groups of processes. 103 * 104 * A simple application should not concern itself with sets at all and 105 * rather apply masks to its own threads via CPU_WHICH_TID and a -1 id 106 * meaning 'curthread'. It may query available cpus for that tid with a 107 * getaffinity call using (CPU_LEVEL_CPUSET, CPU_WHICH_PID, -1, ...). 108 */ 109 static uma_zone_t cpuset_zone; 110 static struct mtx cpuset_lock; 111 static struct setlist cpuset_ids; 112 static struct unrhdr *cpuset_unr; 113 static struct cpuset *cpuset_zero, *cpuset_default; 114 115 /* Return the size of cpuset_t at the kernel level */ 116 SYSCTL_INT(_kern_sched, OID_AUTO, cpusetsize, CTLFLAG_RD | CTLFLAG_CAPRD, 117 SYSCTL_NULL_INT_PTR, sizeof(cpuset_t), "sizeof(cpuset_t)"); 118 119 cpuset_t *cpuset_root; 120 cpuset_t cpuset_domain[MAXMEMDOM]; 121 122 /* 123 * Acquire a reference to a cpuset, all pointers must be tracked with refs. 124 */ 125 struct cpuset * 126 cpuset_ref(struct cpuset *set) 127 { 128 129 refcount_acquire(&set->cs_ref); 130 return (set); 131 } 132 133 /* 134 * Walks up the tree from 'set' to find the root. Returns the root 135 * referenced. 136 */ 137 static struct cpuset * 138 cpuset_refroot(struct cpuset *set) 139 { 140 141 for (; set->cs_parent != NULL; set = set->cs_parent) 142 if (set->cs_flags & CPU_SET_ROOT) 143 break; 144 cpuset_ref(set); 145 146 return (set); 147 } 148 149 /* 150 * Find the first non-anonymous set starting from 'set'. Returns this set 151 * referenced. May return the passed in set with an extra ref if it is 152 * not anonymous. 153 */ 154 static struct cpuset * 155 cpuset_refbase(struct cpuset *set) 156 { 157 158 if (set->cs_id == CPUSET_INVALID) 159 set = set->cs_parent; 160 cpuset_ref(set); 161 162 return (set); 163 } 164 165 /* 166 * Release a reference in a context where it is safe to allocate. 167 */ 168 void 169 cpuset_rel(struct cpuset *set) 170 { 171 cpusetid_t id; 172 173 if (refcount_release(&set->cs_ref) == 0) 174 return; 175 mtx_lock_spin(&cpuset_lock); 176 LIST_REMOVE(set, cs_siblings); 177 id = set->cs_id; 178 if (id != CPUSET_INVALID) 179 LIST_REMOVE(set, cs_link); 180 mtx_unlock_spin(&cpuset_lock); 181 cpuset_rel(set->cs_parent); 182 uma_zfree(cpuset_zone, set); 183 if (id != CPUSET_INVALID) 184 free_unr(cpuset_unr, id); 185 } 186 187 /* 188 * Deferred release must be used when in a context that is not safe to 189 * allocate/free. This places any unreferenced sets on the list 'head'. 190 */ 191 static void 192 cpuset_rel_defer(struct setlist *head, struct cpuset *set) 193 { 194 195 if (refcount_release(&set->cs_ref) == 0) 196 return; 197 mtx_lock_spin(&cpuset_lock); 198 LIST_REMOVE(set, cs_siblings); 199 if (set->cs_id != CPUSET_INVALID) 200 LIST_REMOVE(set, cs_link); 201 LIST_INSERT_HEAD(head, set, cs_link); 202 mtx_unlock_spin(&cpuset_lock); 203 } 204 205 /* 206 * Complete a deferred release. Removes the set from the list provided to 207 * cpuset_rel_defer. 208 */ 209 static void 210 cpuset_rel_complete(struct cpuset *set) 211 { 212 LIST_REMOVE(set, cs_link); 213 cpuset_rel(set->cs_parent); 214 uma_zfree(cpuset_zone, set); 215 } 216 217 /* 218 * Find a set based on an id. Returns it with a ref. 219 */ 220 static struct cpuset * 221 cpuset_lookup(cpusetid_t setid, struct thread *td) 222 { 223 struct cpuset *set; 224 225 if (setid == CPUSET_INVALID) 226 return (NULL); 227 mtx_lock_spin(&cpuset_lock); 228 LIST_FOREACH(set, &cpuset_ids, cs_link) 229 if (set->cs_id == setid) 230 break; 231 if (set) 232 cpuset_ref(set); 233 mtx_unlock_spin(&cpuset_lock); 234 235 KASSERT(td != NULL, ("[%s:%d] td is NULL", __func__, __LINE__)); 236 if (set != NULL && jailed(td->td_ucred)) { 237 struct cpuset *jset, *tset; 238 239 jset = td->td_ucred->cr_prison->pr_cpuset; 240 for (tset = set; tset != NULL; tset = tset->cs_parent) 241 if (tset == jset) 242 break; 243 if (tset == NULL) { 244 cpuset_rel(set); 245 set = NULL; 246 } 247 } 248 249 return (set); 250 } 251 252 /* 253 * Create a set in the space provided in 'set' with the provided parameters. 254 * The set is returned with a single ref. May return EDEADLK if the set 255 * will have no valid cpu based on restrictions from the parent. 256 */ 257 static int 258 _cpuset_create(struct cpuset *set, struct cpuset *parent, const cpuset_t *mask, 259 cpusetid_t id) 260 { 261 262 if (!CPU_OVERLAP(&parent->cs_mask, mask)) 263 return (EDEADLK); 264 CPU_COPY(mask, &set->cs_mask); 265 LIST_INIT(&set->cs_children); 266 refcount_init(&set->cs_ref, 1); 267 set->cs_flags = 0; 268 mtx_lock_spin(&cpuset_lock); 269 CPU_AND(&set->cs_mask, &parent->cs_mask); 270 set->cs_id = id; 271 set->cs_parent = cpuset_ref(parent); 272 LIST_INSERT_HEAD(&parent->cs_children, set, cs_siblings); 273 if (set->cs_id != CPUSET_INVALID) 274 LIST_INSERT_HEAD(&cpuset_ids, set, cs_link); 275 mtx_unlock_spin(&cpuset_lock); 276 277 return (0); 278 } 279 280 /* 281 * Create a new non-anonymous set with the requested parent and mask. May 282 * return failures if the mask is invalid or a new number can not be 283 * allocated. 284 */ 285 static int 286 cpuset_create(struct cpuset **setp, struct cpuset *parent, const cpuset_t *mask) 287 { 288 struct cpuset *set; 289 cpusetid_t id; 290 int error; 291 292 id = alloc_unr(cpuset_unr); 293 if (id == -1) 294 return (ENFILE); 295 *setp = set = uma_zalloc(cpuset_zone, M_WAITOK); 296 error = _cpuset_create(set, parent, mask, id); 297 if (error == 0) 298 return (0); 299 free_unr(cpuset_unr, id); 300 uma_zfree(cpuset_zone, set); 301 302 return (error); 303 } 304 305 /* 306 * Recursively check for errors that would occur from applying mask to 307 * the tree of sets starting at 'set'. Checks for sets that would become 308 * empty as well as RDONLY flags. 309 */ 310 static int 311 cpuset_testupdate(struct cpuset *set, cpuset_t *mask, int check_mask) 312 { 313 struct cpuset *nset; 314 cpuset_t newmask; 315 int error; 316 317 mtx_assert(&cpuset_lock, MA_OWNED); 318 if (set->cs_flags & CPU_SET_RDONLY) 319 return (EPERM); 320 if (check_mask) { 321 if (!CPU_OVERLAP(&set->cs_mask, mask)) 322 return (EDEADLK); 323 CPU_COPY(&set->cs_mask, &newmask); 324 CPU_AND(&newmask, mask); 325 } else 326 CPU_COPY(mask, &newmask); 327 error = 0; 328 LIST_FOREACH(nset, &set->cs_children, cs_siblings) 329 if ((error = cpuset_testupdate(nset, &newmask, 1)) != 0) 330 break; 331 return (error); 332 } 333 334 /* 335 * Applies the mask 'mask' without checking for empty sets or permissions. 336 */ 337 static void 338 cpuset_update(struct cpuset *set, cpuset_t *mask) 339 { 340 struct cpuset *nset; 341 342 mtx_assert(&cpuset_lock, MA_OWNED); 343 CPU_AND(&set->cs_mask, mask); 344 LIST_FOREACH(nset, &set->cs_children, cs_siblings) 345 cpuset_update(nset, &set->cs_mask); 346 347 return; 348 } 349 350 /* 351 * Modify the set 'set' to use a copy of the mask provided. Apply this new 352 * mask to restrict all children in the tree. Checks for validity before 353 * applying the changes. 354 */ 355 static int 356 cpuset_modify(struct cpuset *set, cpuset_t *mask) 357 { 358 struct cpuset *root; 359 int error; 360 361 error = priv_check(curthread, PRIV_SCHED_CPUSET); 362 if (error) 363 return (error); 364 /* 365 * In case we are called from within the jail 366 * we do not allow modifying the dedicated root 367 * cpuset of the jail but may still allow to 368 * change child sets. 369 */ 370 if (jailed(curthread->td_ucred) && 371 set->cs_flags & CPU_SET_ROOT) 372 return (EPERM); 373 /* 374 * Verify that we have access to this set of 375 * cpus. 376 */ 377 root = set->cs_parent; 378 if (root && !CPU_SUBSET(&root->cs_mask, mask)) 379 return (EINVAL); 380 mtx_lock_spin(&cpuset_lock); 381 error = cpuset_testupdate(set, mask, 0); 382 if (error) 383 goto out; 384 CPU_COPY(mask, &set->cs_mask); 385 cpuset_update(set, mask); 386 out: 387 mtx_unlock_spin(&cpuset_lock); 388 389 return (error); 390 } 391 392 /* 393 * Resolve the 'which' parameter of several cpuset apis. 394 * 395 * For WHICH_PID and WHICH_TID return a locked proc and valid proc/tid. Also 396 * checks for permission via p_cansched(). 397 * 398 * For WHICH_SET returns a valid set with a new reference. 399 * 400 * -1 may be supplied for any argument to mean the current proc/thread or 401 * the base set of the current thread. May fail with ESRCH/EPERM. 402 */ 403 int 404 cpuset_which(cpuwhich_t which, id_t id, struct proc **pp, struct thread **tdp, 405 struct cpuset **setp) 406 { 407 struct cpuset *set; 408 struct thread *td; 409 struct proc *p; 410 int error; 411 412 *pp = p = NULL; 413 *tdp = td = NULL; 414 *setp = set = NULL; 415 switch (which) { 416 case CPU_WHICH_PID: 417 if (id == -1) { 418 PROC_LOCK(curproc); 419 p = curproc; 420 break; 421 } 422 if ((p = pfind(id)) == NULL) 423 return (ESRCH); 424 break; 425 case CPU_WHICH_TID: 426 if (id == -1) { 427 PROC_LOCK(curproc); 428 p = curproc; 429 td = curthread; 430 break; 431 } 432 td = tdfind(id, -1); 433 if (td == NULL) 434 return (ESRCH); 435 p = td->td_proc; 436 break; 437 case CPU_WHICH_CPUSET: 438 if (id == -1) { 439 thread_lock(curthread); 440 set = cpuset_refbase(curthread->td_cpuset); 441 thread_unlock(curthread); 442 } else 443 set = cpuset_lookup(id, curthread); 444 if (set) { 445 *setp = set; 446 return (0); 447 } 448 return (ESRCH); 449 case CPU_WHICH_JAIL: 450 { 451 /* Find `set' for prison with given id. */ 452 struct prison *pr; 453 454 sx_slock(&allprison_lock); 455 pr = prison_find_child(curthread->td_ucred->cr_prison, id); 456 sx_sunlock(&allprison_lock); 457 if (pr == NULL) 458 return (ESRCH); 459 cpuset_ref(pr->pr_cpuset); 460 *setp = pr->pr_cpuset; 461 mtx_unlock(&pr->pr_mtx); 462 return (0); 463 } 464 case CPU_WHICH_IRQ: 465 case CPU_WHICH_DOMAIN: 466 return (0); 467 default: 468 return (EINVAL); 469 } 470 error = p_cansched(curthread, p); 471 if (error) { 472 PROC_UNLOCK(p); 473 return (error); 474 } 475 if (td == NULL) 476 td = FIRST_THREAD_IN_PROC(p); 477 *pp = p; 478 *tdp = td; 479 return (0); 480 } 481 482 /* 483 * Create an anonymous set with the provided mask in the space provided by 484 * 'fset'. If the passed in set is anonymous we use its parent otherwise 485 * the new set is a child of 'set'. 486 */ 487 static int 488 cpuset_shadow(struct cpuset *set, struct cpuset *fset, const cpuset_t *mask) 489 { 490 struct cpuset *parent; 491 492 if (set->cs_id == CPUSET_INVALID) 493 parent = set->cs_parent; 494 else 495 parent = set; 496 if (!CPU_SUBSET(&parent->cs_mask, mask)) 497 return (EDEADLK); 498 return (_cpuset_create(fset, parent, mask, CPUSET_INVALID)); 499 } 500 501 /* 502 * Handle two cases for replacing the base set or mask of an entire process. 503 * 504 * 1) Set is non-null and mask is null. This reparents all anonymous sets 505 * to the provided set and replaces all non-anonymous td_cpusets with the 506 * provided set. 507 * 2) Mask is non-null and set is null. This replaces or creates anonymous 508 * sets for every thread with the existing base as a parent. 509 * 510 * This is overly complicated because we can't allocate while holding a 511 * spinlock and spinlocks must be held while changing and examining thread 512 * state. 513 */ 514 static int 515 cpuset_setproc(pid_t pid, struct cpuset *set, cpuset_t *mask) 516 { 517 struct setlist freelist; 518 struct setlist droplist; 519 struct cpuset *tdset; 520 struct cpuset *nset; 521 struct thread *td; 522 struct proc *p; 523 int threads; 524 int nfree; 525 int error; 526 /* 527 * The algorithm requires two passes due to locking considerations. 528 * 529 * 1) Lookup the process and acquire the locks in the required order. 530 * 2) If enough cpusets have not been allocated release the locks and 531 * allocate them. Loop. 532 */ 533 LIST_INIT(&freelist); 534 LIST_INIT(&droplist); 535 nfree = 0; 536 for (;;) { 537 error = cpuset_which(CPU_WHICH_PID, pid, &p, &td, &nset); 538 if (error) 539 goto out; 540 if (nfree >= p->p_numthreads) 541 break; 542 threads = p->p_numthreads; 543 PROC_UNLOCK(p); 544 for (; nfree < threads; nfree++) { 545 nset = uma_zalloc(cpuset_zone, M_WAITOK); 546 LIST_INSERT_HEAD(&freelist, nset, cs_link); 547 } 548 } 549 PROC_LOCK_ASSERT(p, MA_OWNED); 550 /* 551 * Now that the appropriate locks are held and we have enough cpusets, 552 * make sure the operation will succeed before applying changes. The 553 * proc lock prevents td_cpuset from changing between calls. 554 */ 555 error = 0; 556 FOREACH_THREAD_IN_PROC(p, td) { 557 thread_lock(td); 558 tdset = td->td_cpuset; 559 /* 560 * Verify that a new mask doesn't specify cpus outside of 561 * the set the thread is a member of. 562 */ 563 if (mask) { 564 if (tdset->cs_id == CPUSET_INVALID) 565 tdset = tdset->cs_parent; 566 if (!CPU_SUBSET(&tdset->cs_mask, mask)) 567 error = EDEADLK; 568 /* 569 * Verify that a new set won't leave an existing thread 570 * mask without a cpu to run on. It can, however, restrict 571 * the set. 572 */ 573 } else if (tdset->cs_id == CPUSET_INVALID) { 574 if (!CPU_OVERLAP(&set->cs_mask, &tdset->cs_mask)) 575 error = EDEADLK; 576 } 577 thread_unlock(td); 578 if (error) 579 goto unlock_out; 580 } 581 /* 582 * Replace each thread's cpuset while using deferred release. We 583 * must do this because the thread lock must be held while operating 584 * on the thread and this limits the type of operations allowed. 585 */ 586 FOREACH_THREAD_IN_PROC(p, td) { 587 thread_lock(td); 588 /* 589 * If we presently have an anonymous set or are applying a 590 * mask we must create an anonymous shadow set. That is 591 * either parented to our existing base or the supplied set. 592 * 593 * If we have a base set with no anonymous shadow we simply 594 * replace it outright. 595 */ 596 tdset = td->td_cpuset; 597 if (tdset->cs_id == CPUSET_INVALID || mask) { 598 nset = LIST_FIRST(&freelist); 599 LIST_REMOVE(nset, cs_link); 600 if (mask) 601 error = cpuset_shadow(tdset, nset, mask); 602 else 603 error = _cpuset_create(nset, set, 604 &tdset->cs_mask, CPUSET_INVALID); 605 if (error) { 606 LIST_INSERT_HEAD(&freelist, nset, cs_link); 607 thread_unlock(td); 608 break; 609 } 610 } else 611 nset = cpuset_ref(set); 612 cpuset_rel_defer(&droplist, tdset); 613 td->td_cpuset = nset; 614 sched_affinity(td); 615 thread_unlock(td); 616 } 617 unlock_out: 618 PROC_UNLOCK(p); 619 out: 620 while ((nset = LIST_FIRST(&droplist)) != NULL) 621 cpuset_rel_complete(nset); 622 while ((nset = LIST_FIRST(&freelist)) != NULL) { 623 LIST_REMOVE(nset, cs_link); 624 uma_zfree(cpuset_zone, nset); 625 } 626 return (error); 627 } 628 629 /* 630 * Return a string representing a valid layout for a cpuset_t object. 631 * It expects an incoming buffer at least sized as CPUSETBUFSIZ. 632 */ 633 char * 634 cpusetobj_strprint(char *buf, const cpuset_t *set) 635 { 636 char *tbuf; 637 size_t i, bytesp, bufsiz; 638 639 tbuf = buf; 640 bytesp = 0; 641 bufsiz = CPUSETBUFSIZ; 642 643 for (i = 0; i < (_NCPUWORDS - 1); i++) { 644 bytesp = snprintf(tbuf, bufsiz, "%lx,", set->__bits[i]); 645 bufsiz -= bytesp; 646 tbuf += bytesp; 647 } 648 snprintf(tbuf, bufsiz, "%lx", set->__bits[_NCPUWORDS - 1]); 649 return (buf); 650 } 651 652 /* 653 * Build a valid cpuset_t object from a string representation. 654 * It expects an incoming buffer at least sized as CPUSETBUFSIZ. 655 */ 656 int 657 cpusetobj_strscan(cpuset_t *set, const char *buf) 658 { 659 u_int nwords; 660 int i, ret; 661 662 if (strlen(buf) > CPUSETBUFSIZ - 1) 663 return (-1); 664 665 /* Allow to pass a shorter version of the mask when necessary. */ 666 nwords = 1; 667 for (i = 0; buf[i] != '\0'; i++) 668 if (buf[i] == ',') 669 nwords++; 670 if (nwords > _NCPUWORDS) 671 return (-1); 672 673 CPU_ZERO(set); 674 for (i = 0; i < (nwords - 1); i++) { 675 ret = sscanf(buf, "%lx,", &set->__bits[i]); 676 if (ret == 0 || ret == -1) 677 return (-1); 678 buf = strstr(buf, ","); 679 if (buf == NULL) 680 return (-1); 681 buf++; 682 } 683 ret = sscanf(buf, "%lx", &set->__bits[nwords - 1]); 684 if (ret == 0 || ret == -1) 685 return (-1); 686 return (0); 687 } 688 689 /* 690 * Apply an anonymous mask to a single thread. 691 */ 692 int 693 cpuset_setthread(lwpid_t id, cpuset_t *mask) 694 { 695 struct cpuset *nset; 696 struct cpuset *set; 697 struct thread *td; 698 struct proc *p; 699 int error; 700 701 nset = uma_zalloc(cpuset_zone, M_WAITOK); 702 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, &set); 703 if (error) 704 goto out; 705 set = NULL; 706 thread_lock(td); 707 error = cpuset_shadow(td->td_cpuset, nset, mask); 708 if (error == 0) { 709 set = td->td_cpuset; 710 td->td_cpuset = nset; 711 sched_affinity(td); 712 nset = NULL; 713 } 714 thread_unlock(td); 715 PROC_UNLOCK(p); 716 if (set) 717 cpuset_rel(set); 718 out: 719 if (nset) 720 uma_zfree(cpuset_zone, nset); 721 return (error); 722 } 723 724 /* 725 * Apply new cpumask to the ithread. 726 */ 727 int 728 cpuset_setithread(lwpid_t id, int cpu) 729 { 730 struct cpuset *nset, *rset; 731 struct cpuset *parent, *old_set; 732 struct thread *td; 733 struct proc *p; 734 cpusetid_t cs_id; 735 cpuset_t mask; 736 int error; 737 738 nset = uma_zalloc(cpuset_zone, M_WAITOK); 739 rset = uma_zalloc(cpuset_zone, M_WAITOK); 740 cs_id = CPUSET_INVALID; 741 742 CPU_ZERO(&mask); 743 if (cpu == NOCPU) 744 CPU_COPY(cpuset_root, &mask); 745 else 746 CPU_SET(cpu, &mask); 747 748 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, &old_set); 749 if (error != 0 || ((cs_id = alloc_unr(cpuset_unr)) == CPUSET_INVALID)) 750 goto out; 751 752 /* cpuset_which() returns with PROC_LOCK held. */ 753 old_set = td->td_cpuset; 754 755 if (cpu == NOCPU) { 756 757 /* 758 * roll back to default set. We're not using cpuset_shadow() 759 * here because we can fail CPU_SUBSET() check. This can happen 760 * if default set does not contain all CPUs. 761 */ 762 error = _cpuset_create(nset, cpuset_default, &mask, 763 CPUSET_INVALID); 764 765 goto applyset; 766 } 767 768 if (old_set->cs_id == 1 || (old_set->cs_id == CPUSET_INVALID && 769 old_set->cs_parent->cs_id == 1)) { 770 771 /* 772 * Current set is either default (1) or 773 * shadowed version of default set. 774 * 775 * Allocate new root set to be able to shadow it 776 * with any mask. 777 */ 778 error = _cpuset_create(rset, cpuset_zero, 779 &cpuset_zero->cs_mask, cs_id); 780 if (error != 0) { 781 PROC_UNLOCK(p); 782 goto out; 783 } 784 rset->cs_flags |= CPU_SET_ROOT; 785 parent = rset; 786 rset = NULL; 787 cs_id = CPUSET_INVALID; 788 } else { 789 /* Assume existing set was already allocated by previous call */ 790 parent = old_set; 791 old_set = NULL; 792 } 793 794 error = cpuset_shadow(parent, nset, &mask); 795 applyset: 796 if (error == 0) { 797 thread_lock(td); 798 td->td_cpuset = nset; 799 sched_affinity(td); 800 thread_unlock(td); 801 nset = NULL; 802 } else 803 old_set = NULL; 804 PROC_UNLOCK(p); 805 if (old_set != NULL) 806 cpuset_rel(old_set); 807 out: 808 if (nset != NULL) 809 uma_zfree(cpuset_zone, nset); 810 if (rset != NULL) 811 uma_zfree(cpuset_zone, rset); 812 if (cs_id != CPUSET_INVALID) 813 free_unr(cpuset_unr, cs_id); 814 return (error); 815 } 816 817 818 /* 819 * Creates system-wide cpusets and the cpuset for thread0 including two 820 * sets: 821 * 822 * 0 - The root set which should represent all valid processors in the 823 * system. It is initially created with a mask of all processors 824 * because we don't know what processors are valid until cpuset_init() 825 * runs. This set is immutable. 826 * 1 - The default set which all processes are a member of until changed. 827 * This allows an administrator to move all threads off of given cpus to 828 * dedicate them to high priority tasks or save power etc. 829 */ 830 struct cpuset * 831 cpuset_thread0(void) 832 { 833 struct cpuset *set; 834 int error, i; 835 836 cpuset_zone = uma_zcreate("cpuset", sizeof(struct cpuset), NULL, NULL, 837 NULL, NULL, UMA_ALIGN_PTR, 0); 838 mtx_init(&cpuset_lock, "cpuset", NULL, MTX_SPIN | MTX_RECURSE); 839 840 /* 841 * Create the root system set for the whole machine. Doesn't use 842 * cpuset_create() due to NULL parent. 843 */ 844 set = uma_zalloc(cpuset_zone, M_WAITOK | M_ZERO); 845 CPU_FILL(&set->cs_mask); 846 LIST_INIT(&set->cs_children); 847 LIST_INSERT_HEAD(&cpuset_ids, set, cs_link); 848 set->cs_ref = 1; 849 set->cs_flags = CPU_SET_ROOT; 850 cpuset_zero = set; 851 cpuset_root = &set->cs_mask; 852 853 /* 854 * Now derive a default, modifiable set from that to give out. 855 */ 856 set = uma_zalloc(cpuset_zone, M_WAITOK); 857 error = _cpuset_create(set, cpuset_zero, &cpuset_zero->cs_mask, 1); 858 KASSERT(error == 0, ("Error creating default set: %d\n", error)); 859 cpuset_default = set; 860 861 /* 862 * Initialize the unit allocator. 0 and 1 are allocated above. 863 */ 864 cpuset_unr = new_unrhdr(2, INT_MAX, NULL); 865 866 /* 867 * If MD code has not initialized per-domain cpusets, place all 868 * CPUs in domain 0. 869 */ 870 for (i = 0; i < MAXMEMDOM; i++) 871 if (!CPU_EMPTY(&cpuset_domain[i])) 872 goto domains_set; 873 CPU_COPY(&all_cpus, &cpuset_domain[0]); 874 domains_set: 875 876 return (set); 877 } 878 879 /* 880 * Create a cpuset, which would be cpuset_create() but 881 * mark the new 'set' as root. 882 * 883 * We are not going to reparent the td to it. Use cpuset_setproc_update_set() 884 * for that. 885 * 886 * In case of no error, returns the set in *setp locked with a reference. 887 */ 888 int 889 cpuset_create_root(struct prison *pr, struct cpuset **setp) 890 { 891 struct cpuset *set; 892 int error; 893 894 KASSERT(pr != NULL, ("[%s:%d] invalid pr", __func__, __LINE__)); 895 KASSERT(setp != NULL, ("[%s:%d] invalid setp", __func__, __LINE__)); 896 897 error = cpuset_create(setp, pr->pr_cpuset, &pr->pr_cpuset->cs_mask); 898 if (error) 899 return (error); 900 901 KASSERT(*setp != NULL, ("[%s:%d] cpuset_create returned invalid data", 902 __func__, __LINE__)); 903 904 /* Mark the set as root. */ 905 set = *setp; 906 set->cs_flags |= CPU_SET_ROOT; 907 908 return (0); 909 } 910 911 int 912 cpuset_setproc_update_set(struct proc *p, struct cpuset *set) 913 { 914 int error; 915 916 KASSERT(p != NULL, ("[%s:%d] invalid proc", __func__, __LINE__)); 917 KASSERT(set != NULL, ("[%s:%d] invalid set", __func__, __LINE__)); 918 919 cpuset_ref(set); 920 error = cpuset_setproc(p->p_pid, set, NULL); 921 if (error) 922 return (error); 923 cpuset_rel(set); 924 return (0); 925 } 926 927 /* 928 * This is called once the final set of system cpus is known. Modifies 929 * the root set and all children and mark the root read-only. 930 */ 931 static void 932 cpuset_init(void *arg) 933 { 934 cpuset_t mask; 935 936 mask = all_cpus; 937 if (cpuset_modify(cpuset_zero, &mask)) 938 panic("Can't set initial cpuset mask.\n"); 939 cpuset_zero->cs_flags |= CPU_SET_RDONLY; 940 } 941 SYSINIT(cpuset, SI_SUB_SMP, SI_ORDER_ANY, cpuset_init, NULL); 942 943 #ifndef _SYS_SYSPROTO_H_ 944 struct cpuset_args { 945 cpusetid_t *setid; 946 }; 947 #endif 948 int 949 sys_cpuset(struct thread *td, struct cpuset_args *uap) 950 { 951 struct cpuset *root; 952 struct cpuset *set; 953 int error; 954 955 thread_lock(td); 956 root = cpuset_refroot(td->td_cpuset); 957 thread_unlock(td); 958 error = cpuset_create(&set, root, &root->cs_mask); 959 cpuset_rel(root); 960 if (error) 961 return (error); 962 error = copyout(&set->cs_id, uap->setid, sizeof(set->cs_id)); 963 if (error == 0) 964 error = cpuset_setproc(-1, set, NULL); 965 cpuset_rel(set); 966 return (error); 967 } 968 969 #ifndef _SYS_SYSPROTO_H_ 970 struct cpuset_setid_args { 971 cpuwhich_t which; 972 id_t id; 973 cpusetid_t setid; 974 }; 975 #endif 976 int 977 sys_cpuset_setid(struct thread *td, struct cpuset_setid_args *uap) 978 { 979 struct cpuset *set; 980 int error; 981 982 /* 983 * Presently we only support per-process sets. 984 */ 985 if (uap->which != CPU_WHICH_PID) 986 return (EINVAL); 987 set = cpuset_lookup(uap->setid, td); 988 if (set == NULL) 989 return (ESRCH); 990 error = cpuset_setproc(uap->id, set, NULL); 991 cpuset_rel(set); 992 return (error); 993 } 994 995 #ifndef _SYS_SYSPROTO_H_ 996 struct cpuset_getid_args { 997 cpulevel_t level; 998 cpuwhich_t which; 999 id_t id; 1000 cpusetid_t *setid; 1001 }; 1002 #endif 1003 int 1004 sys_cpuset_getid(struct thread *td, struct cpuset_getid_args *uap) 1005 { 1006 struct cpuset *nset; 1007 struct cpuset *set; 1008 struct thread *ttd; 1009 struct proc *p; 1010 cpusetid_t id; 1011 int error; 1012 1013 if (uap->level == CPU_LEVEL_WHICH && uap->which != CPU_WHICH_CPUSET) 1014 return (EINVAL); 1015 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set); 1016 if (error) 1017 return (error); 1018 switch (uap->which) { 1019 case CPU_WHICH_TID: 1020 case CPU_WHICH_PID: 1021 thread_lock(ttd); 1022 set = cpuset_refbase(ttd->td_cpuset); 1023 thread_unlock(ttd); 1024 PROC_UNLOCK(p); 1025 break; 1026 case CPU_WHICH_CPUSET: 1027 case CPU_WHICH_JAIL: 1028 break; 1029 case CPU_WHICH_IRQ: 1030 case CPU_WHICH_DOMAIN: 1031 return (EINVAL); 1032 } 1033 switch (uap->level) { 1034 case CPU_LEVEL_ROOT: 1035 nset = cpuset_refroot(set); 1036 cpuset_rel(set); 1037 set = nset; 1038 break; 1039 case CPU_LEVEL_CPUSET: 1040 break; 1041 case CPU_LEVEL_WHICH: 1042 break; 1043 } 1044 id = set->cs_id; 1045 cpuset_rel(set); 1046 if (error == 0) 1047 error = copyout(&id, uap->setid, sizeof(id)); 1048 1049 return (error); 1050 } 1051 1052 #ifndef _SYS_SYSPROTO_H_ 1053 struct cpuset_getaffinity_args { 1054 cpulevel_t level; 1055 cpuwhich_t which; 1056 id_t id; 1057 size_t cpusetsize; 1058 cpuset_t *mask; 1059 }; 1060 #endif 1061 int 1062 sys_cpuset_getaffinity(struct thread *td, struct cpuset_getaffinity_args *uap) 1063 { 1064 struct thread *ttd; 1065 struct cpuset *nset; 1066 struct cpuset *set; 1067 struct proc *p; 1068 cpuset_t *mask; 1069 int error; 1070 size_t size; 1071 1072 if (uap->cpusetsize < sizeof(cpuset_t) || 1073 uap->cpusetsize > CPU_MAXSIZE / NBBY) 1074 return (ERANGE); 1075 size = uap->cpusetsize; 1076 mask = malloc(size, M_TEMP, M_WAITOK | M_ZERO); 1077 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set); 1078 if (error) 1079 goto out; 1080 switch (uap->level) { 1081 case CPU_LEVEL_ROOT: 1082 case CPU_LEVEL_CPUSET: 1083 switch (uap->which) { 1084 case CPU_WHICH_TID: 1085 case CPU_WHICH_PID: 1086 thread_lock(ttd); 1087 set = cpuset_ref(ttd->td_cpuset); 1088 thread_unlock(ttd); 1089 break; 1090 case CPU_WHICH_CPUSET: 1091 case CPU_WHICH_JAIL: 1092 break; 1093 case CPU_WHICH_IRQ: 1094 case CPU_WHICH_DOMAIN: 1095 error = EINVAL; 1096 goto out; 1097 } 1098 if (uap->level == CPU_LEVEL_ROOT) 1099 nset = cpuset_refroot(set); 1100 else 1101 nset = cpuset_refbase(set); 1102 CPU_COPY(&nset->cs_mask, mask); 1103 cpuset_rel(nset); 1104 break; 1105 case CPU_LEVEL_WHICH: 1106 switch (uap->which) { 1107 case CPU_WHICH_TID: 1108 thread_lock(ttd); 1109 CPU_COPY(&ttd->td_cpuset->cs_mask, mask); 1110 thread_unlock(ttd); 1111 break; 1112 case CPU_WHICH_PID: 1113 FOREACH_THREAD_IN_PROC(p, ttd) { 1114 thread_lock(ttd); 1115 CPU_OR(mask, &ttd->td_cpuset->cs_mask); 1116 thread_unlock(ttd); 1117 } 1118 break; 1119 case CPU_WHICH_CPUSET: 1120 case CPU_WHICH_JAIL: 1121 CPU_COPY(&set->cs_mask, mask); 1122 break; 1123 case CPU_WHICH_IRQ: 1124 error = intr_getaffinity(uap->id, mask); 1125 break; 1126 case CPU_WHICH_DOMAIN: 1127 if (uap->id < 0 || uap->id >= MAXMEMDOM) 1128 error = ESRCH; 1129 else 1130 CPU_COPY(&cpuset_domain[uap->id], mask); 1131 break; 1132 } 1133 break; 1134 default: 1135 error = EINVAL; 1136 break; 1137 } 1138 if (set) 1139 cpuset_rel(set); 1140 if (p) 1141 PROC_UNLOCK(p); 1142 if (error == 0) 1143 error = copyout(mask, uap->mask, size); 1144 out: 1145 free(mask, M_TEMP); 1146 return (error); 1147 } 1148 1149 #ifndef _SYS_SYSPROTO_H_ 1150 struct cpuset_setaffinity_args { 1151 cpulevel_t level; 1152 cpuwhich_t which; 1153 id_t id; 1154 size_t cpusetsize; 1155 const cpuset_t *mask; 1156 }; 1157 #endif 1158 int 1159 sys_cpuset_setaffinity(struct thread *td, struct cpuset_setaffinity_args *uap) 1160 { 1161 struct cpuset *nset; 1162 struct cpuset *set; 1163 struct thread *ttd; 1164 struct proc *p; 1165 cpuset_t *mask; 1166 int error; 1167 1168 if (uap->cpusetsize < sizeof(cpuset_t) || 1169 uap->cpusetsize > CPU_MAXSIZE / NBBY) 1170 return (ERANGE); 1171 mask = malloc(uap->cpusetsize, M_TEMP, M_WAITOK | M_ZERO); 1172 error = copyin(uap->mask, mask, uap->cpusetsize); 1173 if (error) 1174 goto out; 1175 /* 1176 * Verify that no high bits are set. 1177 */ 1178 if (uap->cpusetsize > sizeof(cpuset_t)) { 1179 char *end; 1180 char *cp; 1181 1182 end = cp = (char *)&mask->__bits; 1183 end += uap->cpusetsize; 1184 cp += sizeof(cpuset_t); 1185 while (cp != end) 1186 if (*cp++ != 0) { 1187 error = EINVAL; 1188 goto out; 1189 } 1190 1191 } 1192 switch (uap->level) { 1193 case CPU_LEVEL_ROOT: 1194 case CPU_LEVEL_CPUSET: 1195 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set); 1196 if (error) 1197 break; 1198 switch (uap->which) { 1199 case CPU_WHICH_TID: 1200 case CPU_WHICH_PID: 1201 thread_lock(ttd); 1202 set = cpuset_ref(ttd->td_cpuset); 1203 thread_unlock(ttd); 1204 PROC_UNLOCK(p); 1205 break; 1206 case CPU_WHICH_CPUSET: 1207 case CPU_WHICH_JAIL: 1208 break; 1209 case CPU_WHICH_IRQ: 1210 case CPU_WHICH_DOMAIN: 1211 error = EINVAL; 1212 goto out; 1213 } 1214 if (uap->level == CPU_LEVEL_ROOT) 1215 nset = cpuset_refroot(set); 1216 else 1217 nset = cpuset_refbase(set); 1218 error = cpuset_modify(nset, mask); 1219 cpuset_rel(nset); 1220 cpuset_rel(set); 1221 break; 1222 case CPU_LEVEL_WHICH: 1223 switch (uap->which) { 1224 case CPU_WHICH_TID: 1225 error = cpuset_setthread(uap->id, mask); 1226 break; 1227 case CPU_WHICH_PID: 1228 error = cpuset_setproc(uap->id, NULL, mask); 1229 break; 1230 case CPU_WHICH_CPUSET: 1231 case CPU_WHICH_JAIL: 1232 error = cpuset_which(uap->which, uap->id, &p, 1233 &ttd, &set); 1234 if (error == 0) { 1235 error = cpuset_modify(set, mask); 1236 cpuset_rel(set); 1237 } 1238 break; 1239 case CPU_WHICH_IRQ: 1240 error = intr_setaffinity(uap->id, mask); 1241 break; 1242 default: 1243 error = EINVAL; 1244 break; 1245 } 1246 break; 1247 default: 1248 error = EINVAL; 1249 break; 1250 } 1251 out: 1252 free(mask, M_TEMP); 1253 return (error); 1254 } 1255 1256 #ifdef DDB 1257 void 1258 ddb_display_cpuset(const cpuset_t *set) 1259 { 1260 int cpu, once; 1261 1262 for (once = 0, cpu = 0; cpu < CPU_SETSIZE; cpu++) { 1263 if (CPU_ISSET(cpu, set)) { 1264 if (once == 0) { 1265 db_printf("%d", cpu); 1266 once = 1; 1267 } else 1268 db_printf(",%d", cpu); 1269 } 1270 } 1271 if (once == 0) 1272 db_printf("<none>"); 1273 } 1274 1275 DB_SHOW_COMMAND(cpusets, db_show_cpusets) 1276 { 1277 struct cpuset *set; 1278 1279 LIST_FOREACH(set, &cpuset_ids, cs_link) { 1280 db_printf("set=%p id=%-6u ref=%-6d flags=0x%04x parent id=%d\n", 1281 set, set->cs_id, set->cs_ref, set->cs_flags, 1282 (set->cs_parent != NULL) ? set->cs_parent->cs_id : 0); 1283 db_printf(" mask="); 1284 ddb_display_cpuset(&set->cs_mask); 1285 db_printf("\n"); 1286 if (db_pager_quit) 1287 break; 1288 } 1289 } 1290 #endif /* DDB */
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