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 #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 *
cpuset_ref(struct cpuset * set)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 *
cpuset_refroot(struct cpuset * set)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 *
cpuset_refbase(struct cpuset * set)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
cpuset_rel(struct cpuset * set)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
cpuset_rel_defer(struct setlist * head,struct cpuset * set)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
cpuset_rel_complete(struct cpuset * set)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 *
cpuset_lookup(cpusetid_t setid,struct thread * td)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
_cpuset_create(struct cpuset * set,struct cpuset * parent,const cpuset_t * mask,cpusetid_t id)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
cpuset_create(struct cpuset ** setp,struct cpuset * parent,const cpuset_t * mask)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
cpuset_testupdate(struct cpuset * set,cpuset_t * mask,int check_mask)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
cpuset_update(struct cpuset * set,cpuset_t * mask)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
cpuset_modify(struct cpuset * set,cpuset_t * mask)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
cpuset_which(cpuwhich_t which,id_t id,struct proc ** pp,struct thread ** tdp,struct cpuset ** setp)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
cpuset_shadow(struct cpuset * set,struct cpuset * fset,const cpuset_t * mask)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
cpuset_setproc(pid_t pid,struct cpuset * set,cpuset_t * mask)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 *
cpusetobj_strprint(char * buf,const cpuset_t * set)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
cpusetobj_strscan(cpuset_t * set,const char * buf)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
cpuset_setthread(lwpid_t id,cpuset_t * mask)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
cpuset_setithread(lwpid_t id,int cpu)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 *
cpuset_thread0(void)831 cpuset_thread0(void)
832 {
833 struct cpuset *set;
834 int error;
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 /* MD Code is responsible for initializing sets if vm_ndomains > 1. */
867 if (vm_ndomains == 1)
868 CPU_COPY(&all_cpus, &cpuset_domain[0]);
869
870 return (set);
871 }
872
873 /*
874 * Create a cpuset, which would be cpuset_create() but
875 * mark the new 'set' as root.
876 *
877 * We are not going to reparent the td to it. Use cpuset_setproc_update_set()
878 * for that.
879 *
880 * In case of no error, returns the set in *setp locked with a reference.
881 */
882 int
cpuset_create_root(struct prison * pr,struct cpuset ** setp)883 cpuset_create_root(struct prison *pr, struct cpuset **setp)
884 {
885 struct cpuset *set;
886 int error;
887
888 KASSERT(pr != NULL, ("[%s:%d] invalid pr", __func__, __LINE__));
889 KASSERT(setp != NULL, ("[%s:%d] invalid setp", __func__, __LINE__));
890
891 error = cpuset_create(setp, pr->pr_cpuset, &pr->pr_cpuset->cs_mask);
892 if (error)
893 return (error);
894
895 KASSERT(*setp != NULL, ("[%s:%d] cpuset_create returned invalid data",
896 __func__, __LINE__));
897
898 /* Mark the set as root. */
899 set = *setp;
900 set->cs_flags |= CPU_SET_ROOT;
901
902 return (0);
903 }
904
905 int
cpuset_setproc_update_set(struct proc * p,struct cpuset * set)906 cpuset_setproc_update_set(struct proc *p, struct cpuset *set)
907 {
908 int error;
909
910 KASSERT(p != NULL, ("[%s:%d] invalid proc", __func__, __LINE__));
911 KASSERT(set != NULL, ("[%s:%d] invalid set", __func__, __LINE__));
912
913 cpuset_ref(set);
914 error = cpuset_setproc(p->p_pid, set, NULL);
915 if (error)
916 return (error);
917 cpuset_rel(set);
918 return (0);
919 }
920
921 /*
922 * This is called once the final set of system cpus is known. Modifies
923 * the root set and all children and mark the root read-only.
924 */
925 static void
cpuset_init(void * arg)926 cpuset_init(void *arg)
927 {
928 cpuset_t mask;
929
930 mask = all_cpus;
931 if (cpuset_modify(cpuset_zero, &mask))
932 panic("Can't set initial cpuset mask.\n");
933 cpuset_zero->cs_flags |= CPU_SET_RDONLY;
934 }
935 SYSINIT(cpuset, SI_SUB_SMP, SI_ORDER_ANY, cpuset_init, NULL);
936
937 #ifndef _SYS_SYSPROTO_H_
938 struct cpuset_args {
939 cpusetid_t *setid;
940 };
941 #endif
942 int
sys_cpuset(struct thread * td,struct cpuset_args * uap)943 sys_cpuset(struct thread *td, struct cpuset_args *uap)
944 {
945 struct cpuset *root;
946 struct cpuset *set;
947 int error;
948
949 thread_lock(td);
950 root = cpuset_refroot(td->td_cpuset);
951 thread_unlock(td);
952 error = cpuset_create(&set, root, &root->cs_mask);
953 cpuset_rel(root);
954 if (error)
955 return (error);
956 error = copyout(&set->cs_id, uap->setid, sizeof(set->cs_id));
957 if (error == 0)
958 error = cpuset_setproc(-1, set, NULL);
959 cpuset_rel(set);
960 return (error);
961 }
962
963 #ifndef _SYS_SYSPROTO_H_
964 struct cpuset_setid_args {
965 cpuwhich_t which;
966 id_t id;
967 cpusetid_t setid;
968 };
969 #endif
970 int
sys_cpuset_setid(struct thread * td,struct cpuset_setid_args * uap)971 sys_cpuset_setid(struct thread *td, struct cpuset_setid_args *uap)
972 {
973 struct cpuset *set;
974 int error;
975
976 /*
977 * Presently we only support per-process sets.
978 */
979 if (uap->which != CPU_WHICH_PID)
980 return (EINVAL);
981 set = cpuset_lookup(uap->setid, td);
982 if (set == NULL)
983 return (ESRCH);
984 error = cpuset_setproc(uap->id, set, NULL);
985 cpuset_rel(set);
986 return (error);
987 }
988
989 #ifndef _SYS_SYSPROTO_H_
990 struct cpuset_getid_args {
991 cpulevel_t level;
992 cpuwhich_t which;
993 id_t id;
994 cpusetid_t *setid;
995 };
996 #endif
997 int
sys_cpuset_getid(struct thread * td,struct cpuset_getid_args * uap)998 sys_cpuset_getid(struct thread *td, struct cpuset_getid_args *uap)
999 {
1000 struct cpuset *nset;
1001 struct cpuset *set;
1002 struct thread *ttd;
1003 struct proc *p;
1004 cpusetid_t id;
1005 int error;
1006
1007 if (uap->level == CPU_LEVEL_WHICH && uap->which != CPU_WHICH_CPUSET)
1008 return (EINVAL);
1009 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set);
1010 if (error)
1011 return (error);
1012 switch (uap->which) {
1013 case CPU_WHICH_TID:
1014 case CPU_WHICH_PID:
1015 thread_lock(ttd);
1016 set = cpuset_refbase(ttd->td_cpuset);
1017 thread_unlock(ttd);
1018 PROC_UNLOCK(p);
1019 break;
1020 case CPU_WHICH_CPUSET:
1021 case CPU_WHICH_JAIL:
1022 break;
1023 case CPU_WHICH_IRQ:
1024 case CPU_WHICH_DOMAIN:
1025 return (EINVAL);
1026 }
1027 switch (uap->level) {
1028 case CPU_LEVEL_ROOT:
1029 nset = cpuset_refroot(set);
1030 cpuset_rel(set);
1031 set = nset;
1032 break;
1033 case CPU_LEVEL_CPUSET:
1034 break;
1035 case CPU_LEVEL_WHICH:
1036 break;
1037 }
1038 id = set->cs_id;
1039 cpuset_rel(set);
1040 if (error == 0)
1041 error = copyout(&id, uap->setid, sizeof(id));
1042
1043 return (error);
1044 }
1045
1046 #ifndef _SYS_SYSPROTO_H_
1047 struct cpuset_getaffinity_args {
1048 cpulevel_t level;
1049 cpuwhich_t which;
1050 id_t id;
1051 size_t cpusetsize;
1052 cpuset_t *mask;
1053 };
1054 #endif
1055 int
sys_cpuset_getaffinity(struct thread * td,struct cpuset_getaffinity_args * uap)1056 sys_cpuset_getaffinity(struct thread *td, struct cpuset_getaffinity_args *uap)
1057 {
1058 struct thread *ttd;
1059 struct cpuset *nset;
1060 struct cpuset *set;
1061 struct proc *p;
1062 cpuset_t *mask;
1063 int error;
1064 size_t size;
1065
1066 if (uap->cpusetsize < sizeof(cpuset_t) ||
1067 uap->cpusetsize > CPU_MAXSIZE / NBBY)
1068 return (ERANGE);
1069 size = uap->cpusetsize;
1070 mask = malloc(size, M_TEMP, M_WAITOK | M_ZERO);
1071 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set);
1072 if (error)
1073 goto out;
1074 switch (uap->level) {
1075 case CPU_LEVEL_ROOT:
1076 case CPU_LEVEL_CPUSET:
1077 switch (uap->which) {
1078 case CPU_WHICH_TID:
1079 case CPU_WHICH_PID:
1080 thread_lock(ttd);
1081 set = cpuset_ref(ttd->td_cpuset);
1082 thread_unlock(ttd);
1083 break;
1084 case CPU_WHICH_CPUSET:
1085 case CPU_WHICH_JAIL:
1086 break;
1087 case CPU_WHICH_IRQ:
1088 case CPU_WHICH_DOMAIN:
1089 error = EINVAL;
1090 goto out;
1091 }
1092 if (uap->level == CPU_LEVEL_ROOT)
1093 nset = cpuset_refroot(set);
1094 else
1095 nset = cpuset_refbase(set);
1096 CPU_COPY(&nset->cs_mask, mask);
1097 cpuset_rel(nset);
1098 break;
1099 case CPU_LEVEL_WHICH:
1100 switch (uap->which) {
1101 case CPU_WHICH_TID:
1102 thread_lock(ttd);
1103 CPU_COPY(&ttd->td_cpuset->cs_mask, mask);
1104 thread_unlock(ttd);
1105 break;
1106 case CPU_WHICH_PID:
1107 FOREACH_THREAD_IN_PROC(p, ttd) {
1108 thread_lock(ttd);
1109 CPU_OR(mask, &ttd->td_cpuset->cs_mask);
1110 thread_unlock(ttd);
1111 }
1112 break;
1113 case CPU_WHICH_CPUSET:
1114 case CPU_WHICH_JAIL:
1115 CPU_COPY(&set->cs_mask, mask);
1116 break;
1117 case CPU_WHICH_IRQ:
1118 error = intr_getaffinity(uap->id, mask);
1119 break;
1120 case CPU_WHICH_DOMAIN:
1121 if (uap->id < 0 || uap->id >= vm_ndomains)
1122 error = ESRCH;
1123 else
1124 CPU_COPY(&cpuset_domain[uap->id], mask);
1125 break;
1126 }
1127 break;
1128 default:
1129 error = EINVAL;
1130 break;
1131 }
1132 if (set)
1133 cpuset_rel(set);
1134 if (p)
1135 PROC_UNLOCK(p);
1136 if (error == 0)
1137 error = copyout(mask, uap->mask, size);
1138 out:
1139 free(mask, M_TEMP);
1140 return (error);
1141 }
1142
1143 #ifndef _SYS_SYSPROTO_H_
1144 struct cpuset_setaffinity_args {
1145 cpulevel_t level;
1146 cpuwhich_t which;
1147 id_t id;
1148 size_t cpusetsize;
1149 const cpuset_t *mask;
1150 };
1151 #endif
1152 int
sys_cpuset_setaffinity(struct thread * td,struct cpuset_setaffinity_args * uap)1153 sys_cpuset_setaffinity(struct thread *td, struct cpuset_setaffinity_args *uap)
1154 {
1155 struct cpuset *nset;
1156 struct cpuset *set;
1157 struct thread *ttd;
1158 struct proc *p;
1159 cpuset_t *mask;
1160 int error;
1161
1162 if (uap->cpusetsize < sizeof(cpuset_t) ||
1163 uap->cpusetsize > CPU_MAXSIZE / NBBY)
1164 return (ERANGE);
1165 mask = malloc(uap->cpusetsize, M_TEMP, M_WAITOK | M_ZERO);
1166 error = copyin(uap->mask, mask, uap->cpusetsize);
1167 if (error)
1168 goto out;
1169 /*
1170 * Verify that no high bits are set.
1171 */
1172 if (uap->cpusetsize > sizeof(cpuset_t)) {
1173 char *end;
1174 char *cp;
1175
1176 end = cp = (char *)&mask->__bits;
1177 end += uap->cpusetsize;
1178 cp += sizeof(cpuset_t);
1179 while (cp != end)
1180 if (*cp++ != 0) {
1181 error = EINVAL;
1182 goto out;
1183 }
1184
1185 }
1186 switch (uap->level) {
1187 case CPU_LEVEL_ROOT:
1188 case CPU_LEVEL_CPUSET:
1189 error = cpuset_which(uap->which, uap->id, &p, &ttd, &set);
1190 if (error)
1191 break;
1192 switch (uap->which) {
1193 case CPU_WHICH_TID:
1194 case CPU_WHICH_PID:
1195 thread_lock(ttd);
1196 set = cpuset_ref(ttd->td_cpuset);
1197 thread_unlock(ttd);
1198 PROC_UNLOCK(p);
1199 break;
1200 case CPU_WHICH_CPUSET:
1201 case CPU_WHICH_JAIL:
1202 break;
1203 case CPU_WHICH_IRQ:
1204 case CPU_WHICH_DOMAIN:
1205 error = EINVAL;
1206 goto out;
1207 }
1208 if (uap->level == CPU_LEVEL_ROOT)
1209 nset = cpuset_refroot(set);
1210 else
1211 nset = cpuset_refbase(set);
1212 error = cpuset_modify(nset, mask);
1213 cpuset_rel(nset);
1214 cpuset_rel(set);
1215 break;
1216 case CPU_LEVEL_WHICH:
1217 switch (uap->which) {
1218 case CPU_WHICH_TID:
1219 error = cpuset_setthread(uap->id, mask);
1220 break;
1221 case CPU_WHICH_PID:
1222 error = cpuset_setproc(uap->id, NULL, mask);
1223 break;
1224 case CPU_WHICH_CPUSET:
1225 case CPU_WHICH_JAIL:
1226 error = cpuset_which(uap->which, uap->id, &p,
1227 &ttd, &set);
1228 if (error == 0) {
1229 error = cpuset_modify(set, mask);
1230 cpuset_rel(set);
1231 }
1232 break;
1233 case CPU_WHICH_IRQ:
1234 error = intr_setaffinity(uap->id, mask);
1235 break;
1236 default:
1237 error = EINVAL;
1238 break;
1239 }
1240 break;
1241 default:
1242 error = EINVAL;
1243 break;
1244 }
1245 out:
1246 free(mask, M_TEMP);
1247 return (error);
1248 }
1249
1250 #ifdef DDB
1251 void
ddb_display_cpuset(const cpuset_t * set)1252 ddb_display_cpuset(const cpuset_t *set)
1253 {
1254 int cpu, once;
1255
1256 for (once = 0, cpu = 0; cpu < CPU_SETSIZE; cpu++) {
1257 if (CPU_ISSET(cpu, set)) {
1258 if (once == 0) {
1259 db_printf("%d", cpu);
1260 once = 1;
1261 } else
1262 db_printf(",%d", cpu);
1263 }
1264 }
1265 if (once == 0)
1266 db_printf("<none>");
1267 }
1268
DB_SHOW_COMMAND(cpusets,db_show_cpusets)1269 DB_SHOW_COMMAND(cpusets, db_show_cpusets)
1270 {
1271 struct cpuset *set;
1272
1273 LIST_FOREACH(set, &cpuset_ids, cs_link) {
1274 db_printf("set=%p id=%-6u ref=%-6d flags=0x%04x parent id=%d\n",
1275 set, set->cs_id, set->cs_ref, set->cs_flags,
1276 (set->cs_parent != NULL) ? set->cs_parent->cs_id : 0);
1277 db_printf(" mask=");
1278 ddb_display_cpuset(&set->cs_mask);
1279 db_printf("\n");
1280 if (db_pager_quit)
1281 break;
1282 }
1283 }
1284 #endif /* DDB */
1285