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