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/9.0/sys/kern/kern_cpuset.c 225617 2011-09-16 13:58:51Z kmacy $");
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 0, 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)
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 (!CPU_OVERLAP(&set->cs_mask, mask))
316 return (EDEADLK);
317 CPU_COPY(&set->cs_mask, &newmask);
318 CPU_AND(&newmask, mask);
319 error = 0;
320 LIST_FOREACH(nset, &set->cs_children, cs_siblings)
321 if ((error = cpuset_testupdate(nset, &newmask)) != 0)
322 break;
323 return (error);
324 }
325
326 /*
327 * Applies the mask 'mask' without checking for empty sets or permissions.
328 */
329 static void
330 cpuset_update(struct cpuset *set, cpuset_t *mask)
331 {
332 struct cpuset *nset;
333
334 mtx_assert(&cpuset_lock, MA_OWNED);
335 CPU_AND(&set->cs_mask, mask);
336 LIST_FOREACH(nset, &set->cs_children, cs_siblings)
337 cpuset_update(nset, &set->cs_mask);
338
339 return;
340 }
341
342 /*
343 * Modify the set 'set' to use a copy of the mask provided. Apply this new
344 * mask to restrict all children in the tree. Checks for validity before
345 * applying the changes.
346 */
347 static int
348 cpuset_modify(struct cpuset *set, cpuset_t *mask)
349 {
350 struct cpuset *root;
351 int error;
352
353 error = priv_check(curthread, PRIV_SCHED_CPUSET);
354 if (error)
355 return (error);
356 /*
357 * In case we are called from within the jail
358 * we do not allow modifying the dedicated root
359 * cpuset of the jail but may still allow to
360 * change child sets.
361 */
362 if (jailed(curthread->td_ucred) &&
363 set->cs_flags & CPU_SET_ROOT)
364 return (EPERM);
365 /*
366 * Verify that we have access to this set of
367 * cpus.
368 */
369 root = set->cs_parent;
370 if (root && !CPU_SUBSET(&root->cs_mask, mask))
371 return (EINVAL);
372 mtx_lock_spin(&cpuset_lock);
373 error = cpuset_testupdate(set, mask);
374 if (error)
375 goto out;
376 cpuset_update(set, mask);
377 CPU_COPY(mask, &set->cs_mask);
378 out:
379 mtx_unlock_spin(&cpuset_lock);
380
381 return (error);
382 }
383
384 /*
385 * Resolve the 'which' parameter of several cpuset apis.
386 *
387 * For WHICH_PID and WHICH_TID return a locked proc and valid proc/tid. Also
388 * checks for permission via p_cansched().
389 *
390 * For WHICH_SET returns a valid set with a new reference.
391 *
392 * -1 may be supplied for any argument to mean the current proc/thread or
393 * the base set of the current thread. May fail with ESRCH/EPERM.
394 */
395 static int
396 cpuset_which(cpuwhich_t which, id_t id, struct proc **pp, struct thread **tdp,
397 struct cpuset **setp)
398 {
399 struct cpuset *set;
400 struct thread *td;
401 struct proc *p;
402 int error;
403
404 *pp = p = NULL;
405 *tdp = td = NULL;
406 *setp = set = NULL;
407 switch (which) {
408 case CPU_WHICH_PID:
409 if (id == -1) {
410 PROC_LOCK(curproc);
411 p = curproc;
412 break;
413 }
414 if ((p = pfind(id)) == NULL)
415 return (ESRCH);
416 break;
417 case CPU_WHICH_TID:
418 if (id == -1) {
419 PROC_LOCK(curproc);
420 p = curproc;
421 td = curthread;
422 break;
423 }
424 td = tdfind(id, -1);
425 if (td == NULL)
426 return (ESRCH);
427 p = td->td_proc;
428 break;
429 case CPU_WHICH_CPUSET:
430 if (id == -1) {
431 thread_lock(curthread);
432 set = cpuset_refbase(curthread->td_cpuset);
433 thread_unlock(curthread);
434 } else
435 set = cpuset_lookup(id, curthread);
436 if (set) {
437 *setp = set;
438 return (0);
439 }
440 return (ESRCH);
441 case CPU_WHICH_JAIL:
442 {
443 /* Find `set' for prison with given id. */
444 struct prison *pr;
445
446 sx_slock(&allprison_lock);
447 pr = prison_find_child(curthread->td_ucred->cr_prison, id);
448 sx_sunlock(&allprison_lock);
449 if (pr == NULL)
450 return (ESRCH);
451 cpuset_ref(pr->pr_cpuset);
452 *setp = pr->pr_cpuset;
453 mtx_unlock(&pr->pr_mtx);
454 return (0);
455 }
456 case CPU_WHICH_IRQ:
457 return (0);
458 default:
459 return (EINVAL);
460 }
461 error = p_cansched(curthread, p);
462 if (error) {
463 PROC_UNLOCK(p);
464 return (error);
465 }
466 if (td == NULL)
467 td = FIRST_THREAD_IN_PROC(p);
468 *pp = p;
469 *tdp = td;
470 return (0);
471 }
472
473 /*
474 * Create an anonymous set with the provided mask in the space provided by
475 * 'fset'. If the passed in set is anonymous we use its parent otherwise
476 * the new set is a child of 'set'.
477 */
478 static int
479 cpuset_shadow(struct cpuset *set, struct cpuset *fset, const cpuset_t *mask)
480 {
481 struct cpuset *parent;
482
483 if (set->cs_id == CPUSET_INVALID)
484 parent = set->cs_parent;
485 else
486 parent = set;
487 if (!CPU_SUBSET(&parent->cs_mask, mask))
488 return (EDEADLK);
489 return (_cpuset_create(fset, parent, mask, CPUSET_INVALID));
490 }
491
492 /*
493 * Handle two cases for replacing the base set or mask of an entire process.
494 *
495 * 1) Set is non-null and mask is null. This reparents all anonymous sets
496 * to the provided set and replaces all non-anonymous td_cpusets with the
497 * provided set.
498 * 2) Mask is non-null and set is null. This replaces or creates anonymous
499 * sets for every thread with the existing base as a parent.
500 *
501 * This is overly complicated because we can't allocate while holding a
502 * spinlock and spinlocks must be held while changing and examining thread
503 * state.
504 */
505 static int
506 cpuset_setproc(pid_t pid, struct cpuset *set, cpuset_t *mask)
507 {
508 struct setlist freelist;
509 struct setlist droplist;
510 struct cpuset *tdset;
511 struct cpuset *nset;
512 struct thread *td;
513 struct proc *p;
514 int threads;
515 int nfree;
516 int error;
517 /*
518 * The algorithm requires two passes due to locking considerations.
519 *
520 * 1) Lookup the process and acquire the locks in the required order.
521 * 2) If enough cpusets have not been allocated release the locks and
522 * allocate them. Loop.
523 */
524 LIST_INIT(&freelist);
525 LIST_INIT(&droplist);
526 nfree = 0;
527 for (;;) {
528 error = cpuset_which(CPU_WHICH_PID, pid, &p, &td, &nset);
529 if (error)
530 goto out;
531 if (nfree >= p->p_numthreads)
532 break;
533 threads = p->p_numthreads;
534 PROC_UNLOCK(p);
535 for (; nfree < threads; nfree++) {
536 nset = uma_zalloc(cpuset_zone, M_WAITOK);
537 LIST_INSERT_HEAD(&freelist, nset, cs_link);
538 }
539 }
540 PROC_LOCK_ASSERT(p, MA_OWNED);
541 /*
542 * Now that the appropriate locks are held and we have enough cpusets,
543 * make sure the operation will succeed before applying changes. The
544 * proc lock prevents td_cpuset from changing between calls.
545 */
546 error = 0;
547 FOREACH_THREAD_IN_PROC(p, td) {
548 thread_lock(td);
549 tdset = td->td_cpuset;
550 /*
551 * Verify that a new mask doesn't specify cpus outside of
552 * the set the thread is a member of.
553 */
554 if (mask) {
555 if (tdset->cs_id == CPUSET_INVALID)
556 tdset = tdset->cs_parent;
557 if (!CPU_SUBSET(&tdset->cs_mask, mask))
558 error = EDEADLK;
559 /*
560 * Verify that a new set won't leave an existing thread
561 * mask without a cpu to run on. It can, however, restrict
562 * the set.
563 */
564 } else if (tdset->cs_id == CPUSET_INVALID) {
565 if (!CPU_OVERLAP(&set->cs_mask, &tdset->cs_mask))
566 error = EDEADLK;
567 }
568 thread_unlock(td);
569 if (error)
570 goto unlock_out;
571 }
572 /*
573 * Replace each thread's cpuset while using deferred release. We
574 * must do this because the thread lock must be held while operating
575 * on the thread and this limits the type of operations allowed.
576 */
577 FOREACH_THREAD_IN_PROC(p, td) {
578 thread_lock(td);
579 /*
580 * If we presently have an anonymous set or are applying a
581 * mask we must create an anonymous shadow set. That is
582 * either parented to our existing base or the supplied set.
583 *
584 * If we have a base set with no anonymous shadow we simply
585 * replace it outright.
586 */
587 tdset = td->td_cpuset;
588 if (tdset->cs_id == CPUSET_INVALID || mask) {
589 nset = LIST_FIRST(&freelist);
590 LIST_REMOVE(nset, cs_link);
591 if (mask)
592 error = cpuset_shadow(tdset, nset, mask);
593 else
594 error = _cpuset_create(nset, set,
595 &tdset->cs_mask, CPUSET_INVALID);
596 if (error) {
597 LIST_INSERT_HEAD(&freelist, nset, cs_link);
598 thread_unlock(td);
599 break;
600 }
601 } else
602 nset = cpuset_ref(set);
603 cpuset_rel_defer(&droplist, tdset);
604 td->td_cpuset = nset;
605 sched_affinity(td);
606 thread_unlock(td);
607 }
608 unlock_out:
609 PROC_UNLOCK(p);
610 out:
611 while ((nset = LIST_FIRST(&droplist)) != NULL)
612 cpuset_rel_complete(nset);
613 while ((nset = LIST_FIRST(&freelist)) != NULL) {
614 LIST_REMOVE(nset, cs_link);
615 uma_zfree(cpuset_zone, nset);
616 }
617 return (error);
618 }
619
620 /*
621 * Calculate the ffs() of the cpuset.
622 */
623 int
624 cpusetobj_ffs(const cpuset_t *set)
625 {
626 size_t i;
627 int cbit;
628
629 cbit = 0;
630 for (i = 0; i < _NCPUWORDS; i++) {
631 if (set->__bits[i] != 0) {
632 cbit = ffsl(set->__bits[i]);
633 cbit += i * _NCPUBITS;
634 break;
635 }
636 }
637 return (cbit);
638 }
639
640 /*
641 * Return a string representing a valid layout for a cpuset_t object.
642 * It expects an incoming buffer at least sized as CPUSETBUFSIZ.
643 */
644 char *
645 cpusetobj_strprint(char *buf, const cpuset_t *set)
646 {
647 char *tbuf;
648 size_t i, bytesp, bufsiz;
649
650 tbuf = buf;
651 bytesp = 0;
652 bufsiz = CPUSETBUFSIZ;
653
654 for (i = _NCPUWORDS - 1; i > 0; i--) {
655 bytesp = snprintf(tbuf, bufsiz, "%lx, ", set->__bits[i]);
656 bufsiz -= bytesp;
657 tbuf += bytesp;
658 }
659 snprintf(tbuf, bufsiz, "%lx", set->__bits[0]);
660 return (buf);
661 }
662
663 /*
664 * Build a valid cpuset_t object from a string representation.
665 * It expects an incoming buffer at least sized as CPUSETBUFSIZ.
666 */
667 int
668 cpusetobj_strscan(cpuset_t *set, const char *buf)
669 {
670 u_int nwords;
671 int i, ret;
672
673 if (strlen(buf) > CPUSETBUFSIZ - 1)
674 return (-1);
675
676 /* Allow to pass a shorter version of the mask when necessary. */
677 nwords = 1;
678 for (i = 0; buf[i] != '\0'; i++)
679 if (buf[i] == ',')
680 nwords++;
681 if (nwords > _NCPUWORDS)
682 return (-1);
683
684 CPU_ZERO(set);
685 for (i = nwords - 1; i > 0; i--) {
686 ret = sscanf(buf, "%lx, ", &set->__bits[i]);
687 if (ret == 0 || ret == -1)
688 return (-1);
689 buf = strstr(buf, " ");
690 if (buf == NULL)
691 return (-1);
692 buf++;
693 }
694 ret = sscanf(buf, "%lx", &set->__bits[0]);
695 if (ret == 0 || ret == -1)
696 return (-1);
697 return (0);
698 }
699
700 /*
701 * Apply an anonymous mask to a single thread.
702 */
703 int
704 cpuset_setthread(lwpid_t id, cpuset_t *mask)
705 {
706 struct cpuset *nset;
707 struct cpuset *set;
708 struct thread *td;
709 struct proc *p;
710 int error;
711
712 nset = uma_zalloc(cpuset_zone, M_WAITOK);
713 error = cpuset_which(CPU_WHICH_TID, id, &p, &td, &set);
714 if (error)
715 goto out;
716 set = NULL;
717 thread_lock(td);
718 error = cpuset_shadow(td->td_cpuset, nset, mask);
719 if (error == 0) {
720 set = td->td_cpuset;
721 td->td_cpuset = nset;
722 sched_affinity(td);
723 nset = NULL;
724 }
725 thread_unlock(td);
726 PROC_UNLOCK(p);
727 if (set)
728 cpuset_rel(set);
729 out:
730 if (nset)
731 uma_zfree(cpuset_zone, nset);
732 return (error);
733 }
734
735 /*
736 * Creates the cpuset for thread0. We make two sets:
737 *
738 * 0 - The root set which should represent all valid processors in the
739 * system. It is initially created with a mask of all processors
740 * because we don't know what processors are valid until cpuset_init()
741 * runs. This set is immutable.
742 * 1 - The default set which all processes are a member of until changed.
743 * This allows an administrator to move all threads off of given cpus to
744 * dedicate them to high priority tasks or save power etc.
745 */
746 struct cpuset *
747 cpuset_thread0(void)
748 {
749 struct cpuset *set;
750 int error;
751
752 cpuset_zone = uma_zcreate("cpuset", sizeof(struct cpuset), NULL, NULL,
753 NULL, NULL, UMA_ALIGN_PTR, 0);
754 mtx_init(&cpuset_lock, "cpuset", NULL, MTX_SPIN | MTX_RECURSE);
755 /*
756 * Create the root system set for the whole machine. Doesn't use
757 * cpuset_create() due to NULL parent.
758 */
759 set = uma_zalloc(cpuset_zone, M_WAITOK | M_ZERO);
760 CPU_FILL(&set->cs_mask);
761 LIST_INIT(&set->cs_children);
762 LIST_INSERT_HEAD(&cpuset_ids, set, cs_link);
763 set->cs_ref = 1;
764 set->cs_flags = CPU_SET_ROOT;
765 cpuset_zero = set;
766 cpuset_root = &set->cs_mask;
767 /*
768 * Now derive a default, modifiable set from that to give out.
769 */
770 set = uma_zalloc(cpuset_zone, M_WAITOK);
771 error = _cpuset_create(set, cpuset_zero, &cpuset_zero->cs_mask, 1);
772 KASSERT(error == 0, ("Error creating default set: %d\n", error));
773 /*
774 * Initialize the unit allocator. 0 and 1 are allocated above.
775 */
776 cpuset_unr = new_unrhdr(2, INT_MAX, NULL);
777
778 return (set);
779 }
780
781 /*
782 * Create a cpuset, which would be cpuset_create() but
783 * mark the new 'set' as root.
784 *
785 * We are not going to reparent the td to it. Use cpuset_setproc_update_set()
786 * for that.
787 *
788 * In case of no error, returns the set in *setp locked with a reference.
789 */
790 int
791 cpuset_create_root(struct prison *pr, struct cpuset **setp)
792 {
793 struct cpuset *set;
794 int error;
795
796 KASSERT(pr != NULL, ("[%s:%d] invalid pr", __func__, __LINE__));
797 KASSERT(setp != NULL, ("[%s:%d] invalid setp", __func__, __LINE__));
798
799 error = cpuset_create(setp, pr->pr_cpuset, &pr->pr_cpuset->cs_mask);
800 if (error)
801 return (error);
802
803 KASSERT(*setp != NULL, ("[%s:%d] cpuset_create returned invalid data",
804 __func__, __LINE__));
805
806 /* Mark the set as root. */
807 set = *setp;
808 set->cs_flags |= CPU_SET_ROOT;
809
810 return (0);
811 }
812
813 int
814 cpuset_setproc_update_set(struct proc *p, struct cpuset *set)
815 {
816 int error;
817
818 KASSERT(p != NULL, ("[%s:%d] invalid proc", __func__, __LINE__));
819 KASSERT(set != NULL, ("[%s:%d] invalid set", __func__, __LINE__));
820
821 cpuset_ref(set);
822 error = cpuset_setproc(p->p_pid, set, NULL);
823 if (error)
824 return (error);
825 cpuset_rel(set);
826 return (0);
827 }
828
829 /*
830 * This is called once the final set of system cpus is known. Modifies
831 * the root set and all children and mark the root read-only.
832 */
833 static void
834 cpuset_init(void *arg)
835 {
836 cpuset_t mask;
837
838 mask = all_cpus;
839 if (cpuset_modify(cpuset_zero, &mask))
840 panic("Can't set initial cpuset mask.\n");
841 cpuset_zero->cs_flags |= CPU_SET_RDONLY;
842 }
843 SYSINIT(cpuset, SI_SUB_SMP, SI_ORDER_ANY, cpuset_init, NULL);
844
845 #ifndef _SYS_SYSPROTO_H_
846 struct cpuset_args {
847 cpusetid_t *setid;
848 };
849 #endif
850 int
851 sys_cpuset(struct thread *td, struct cpuset_args *uap)
852 {
853 struct cpuset *root;
854 struct cpuset *set;
855 int error;
856
857 thread_lock(td);
858 root = cpuset_refroot(td->td_cpuset);
859 thread_unlock(td);
860 error = cpuset_create(&set, root, &root->cs_mask);
861 cpuset_rel(root);
862 if (error)
863 return (error);
864 error = copyout(&set->cs_id, uap->setid, sizeof(set->cs_id));
865 if (error == 0)
866 error = cpuset_setproc(-1, set, NULL);
867 cpuset_rel(set);
868 return (error);
869 }
870
871 #ifndef _SYS_SYSPROTO_H_
872 struct cpuset_setid_args {
873 cpuwhich_t which;
874 id_t id;
875 cpusetid_t setid;
876 };
877 #endif
878 int
879 sys_cpuset_setid(struct thread *td, struct cpuset_setid_args *uap)
880 {
881 struct cpuset *set;
882 int error;
883
884 /*
885 * Presently we only support per-process sets.
886 */
887 if (uap->which != CPU_WHICH_PID)
888 return (EINVAL);
889 set = cpuset_lookup(uap->setid, td);
890 if (set == NULL)
891 return (ESRCH);
892 error = cpuset_setproc(uap->id, set, NULL);
893 cpuset_rel(set);
894 return (error);
895 }
896
897 #ifndef _SYS_SYSPROTO_H_
898 struct cpuset_getid_args {
899 cpulevel_t level;
900 cpuwhich_t which;
901 id_t id;
902 cpusetid_t *setid;
903 #endif
904 int
905 sys_cpuset_getid(struct thread *td, struct cpuset_getid_args *uap)
906 {
907 struct cpuset *nset;
908 struct cpuset *set;
909 struct thread *ttd;
910 struct proc *p;
911 cpusetid_t id;
912 int error;
913
914 if (uap->level == CPU_LEVEL_WHICH && uap->which != CPU_WHICH_CPUSET)
915 return (EINVAL);
916 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set);
917 if (error)
918 return (error);
919 switch (uap->which) {
920 case CPU_WHICH_TID:
921 case CPU_WHICH_PID:
922 thread_lock(ttd);
923 set = cpuset_refbase(ttd->td_cpuset);
924 thread_unlock(ttd);
925 PROC_UNLOCK(p);
926 break;
927 case CPU_WHICH_CPUSET:
928 case CPU_WHICH_JAIL:
929 break;
930 case CPU_WHICH_IRQ:
931 return (EINVAL);
932 }
933 switch (uap->level) {
934 case CPU_LEVEL_ROOT:
935 nset = cpuset_refroot(set);
936 cpuset_rel(set);
937 set = nset;
938 break;
939 case CPU_LEVEL_CPUSET:
940 break;
941 case CPU_LEVEL_WHICH:
942 break;
943 }
944 id = set->cs_id;
945 cpuset_rel(set);
946 if (error == 0)
947 error = copyout(&id, uap->setid, sizeof(id));
948
949 return (error);
950 }
951
952 #ifndef _SYS_SYSPROTO_H_
953 struct cpuset_getaffinity_args {
954 cpulevel_t level;
955 cpuwhich_t which;
956 id_t id;
957 size_t cpusetsize;
958 cpuset_t *mask;
959 };
960 #endif
961 int
962 sys_cpuset_getaffinity(struct thread *td, struct cpuset_getaffinity_args *uap)
963 {
964 struct thread *ttd;
965 struct cpuset *nset;
966 struct cpuset *set;
967 struct proc *p;
968 cpuset_t *mask;
969 int error;
970 size_t size;
971
972 if (uap->cpusetsize < sizeof(cpuset_t) ||
973 uap->cpusetsize > CPU_MAXSIZE / NBBY)
974 return (ERANGE);
975 size = uap->cpusetsize;
976 mask = malloc(size, M_TEMP, M_WAITOK | M_ZERO);
977 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set);
978 if (error)
979 goto out;
980 switch (uap->level) {
981 case CPU_LEVEL_ROOT:
982 case CPU_LEVEL_CPUSET:
983 switch (uap->which) {
984 case CPU_WHICH_TID:
985 case CPU_WHICH_PID:
986 thread_lock(ttd);
987 set = cpuset_ref(ttd->td_cpuset);
988 thread_unlock(ttd);
989 break;
990 case CPU_WHICH_CPUSET:
991 case CPU_WHICH_JAIL:
992 break;
993 case CPU_WHICH_IRQ:
994 error = EINVAL;
995 goto out;
996 }
997 if (uap->level == CPU_LEVEL_ROOT)
998 nset = cpuset_refroot(set);
999 else
1000 nset = cpuset_refbase(set);
1001 CPU_COPY(&nset->cs_mask, mask);
1002 cpuset_rel(nset);
1003 break;
1004 case CPU_LEVEL_WHICH:
1005 switch (uap->which) {
1006 case CPU_WHICH_TID:
1007 thread_lock(ttd);
1008 CPU_COPY(&ttd->td_cpuset->cs_mask, mask);
1009 thread_unlock(ttd);
1010 break;
1011 case CPU_WHICH_PID:
1012 FOREACH_THREAD_IN_PROC(p, ttd) {
1013 thread_lock(ttd);
1014 CPU_OR(mask, &ttd->td_cpuset->cs_mask);
1015 thread_unlock(ttd);
1016 }
1017 break;
1018 case CPU_WHICH_CPUSET:
1019 case CPU_WHICH_JAIL:
1020 CPU_COPY(&set->cs_mask, mask);
1021 break;
1022 case CPU_WHICH_IRQ:
1023 error = intr_getaffinity(uap->id, mask);
1024 break;
1025 }
1026 break;
1027 default:
1028 error = EINVAL;
1029 break;
1030 }
1031 if (set)
1032 cpuset_rel(set);
1033 if (p)
1034 PROC_UNLOCK(p);
1035 if (error == 0)
1036 error = copyout(mask, uap->mask, size);
1037 out:
1038 free(mask, M_TEMP);
1039 return (error);
1040 }
1041
1042 #ifndef _SYS_SYSPROTO_H_
1043 struct cpuset_setaffinity_args {
1044 cpulevel_t level;
1045 cpuwhich_t which;
1046 id_t id;
1047 size_t cpusetsize;
1048 const cpuset_t *mask;
1049 };
1050 #endif
1051 int
1052 sys_cpuset_setaffinity(struct thread *td, struct cpuset_setaffinity_args *uap)
1053 {
1054 struct cpuset *nset;
1055 struct cpuset *set;
1056 struct thread *ttd;
1057 struct proc *p;
1058 cpuset_t *mask;
1059 int error;
1060
1061 if (uap->cpusetsize < sizeof(cpuset_t) ||
1062 uap->cpusetsize > CPU_MAXSIZE / NBBY)
1063 return (ERANGE);
1064 mask = malloc(uap->cpusetsize, M_TEMP, M_WAITOK | M_ZERO);
1065 error = copyin(uap->mask, mask, uap->cpusetsize);
1066 if (error)
1067 goto out;
1068 /*
1069 * Verify that no high bits are set.
1070 */
1071 if (uap->cpusetsize > sizeof(cpuset_t)) {
1072 char *end;
1073 char *cp;
1074
1075 end = cp = (char *)&mask->__bits;
1076 end += uap->cpusetsize;
1077 cp += sizeof(cpuset_t);
1078 while (cp != end)
1079 if (*cp++ != 0) {
1080 error = EINVAL;
1081 goto out;
1082 }
1083
1084 }
1085 switch (uap->level) {
1086 case CPU_LEVEL_ROOT:
1087 case CPU_LEVEL_CPUSET:
1088 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set);
1089 if (error)
1090 break;
1091 switch (uap->which) {
1092 case CPU_WHICH_TID:
1093 case CPU_WHICH_PID:
1094 thread_lock(ttd);
1095 set = cpuset_ref(ttd->td_cpuset);
1096 thread_unlock(ttd);
1097 PROC_UNLOCK(p);
1098 break;
1099 case CPU_WHICH_CPUSET:
1100 case CPU_WHICH_JAIL:
1101 break;
1102 case CPU_WHICH_IRQ:
1103 error = EINVAL;
1104 goto out;
1105 }
1106 if (uap->level == CPU_LEVEL_ROOT)
1107 nset = cpuset_refroot(set);
1108 else
1109 nset = cpuset_refbase(set);
1110 error = cpuset_modify(nset, mask);
1111 cpuset_rel(nset);
1112 cpuset_rel(set);
1113 break;
1114 case CPU_LEVEL_WHICH:
1115 switch (uap->which) {
1116 case CPU_WHICH_TID:
1117 error = cpuset_setthread(uap->id, mask);
1118 break;
1119 case CPU_WHICH_PID:
1120 error = cpuset_setproc(uap->id, NULL, mask);
1121 break;
1122 case CPU_WHICH_CPUSET:
1123 case CPU_WHICH_JAIL:
1124 error = cpuset_which(uap->which, uap->id, &p,
1125 &ttd, &set);
1126 if (error == 0) {
1127 error = cpuset_modify(set, mask);
1128 cpuset_rel(set);
1129 }
1130 break;
1131 case CPU_WHICH_IRQ:
1132 error = intr_setaffinity(uap->id, mask);
1133 break;
1134 default:
1135 error = EINVAL;
1136 break;
1137 }
1138 break;
1139 default:
1140 error = EINVAL;
1141 break;
1142 }
1143 out:
1144 free(mask, M_TEMP);
1145 return (error);
1146 }
1147
1148 #ifdef DDB
1149 DB_SHOW_COMMAND(cpusets, db_show_cpusets)
1150 {
1151 struct cpuset *set;
1152 int cpu, once;
1153
1154 LIST_FOREACH(set, &cpuset_ids, cs_link) {
1155 db_printf("set=%p id=%-6u ref=%-6d flags=0x%04x parent id=%d\n",
1156 set, set->cs_id, set->cs_ref, set->cs_flags,
1157 (set->cs_parent != NULL) ? set->cs_parent->cs_id : 0);
1158 db_printf(" mask=");
1159 for (once = 0, cpu = 0; cpu < CPU_SETSIZE; cpu++) {
1160 if (CPU_ISSET(cpu, &set->cs_mask)) {
1161 if (once == 0) {
1162 db_printf("%d", cpu);
1163 once = 1;
1164 } else
1165 db_printf(",%d", cpu);
1166 }
1167 }
1168 db_printf("\n");
1169 if (db_pager_quit)
1170 break;
1171 }
1172 }
1173 #endif /* DDB */
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