xref: /freebsd/sys/kern/kern_racct.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2010 The FreeBSD Foundation
5  *
6  * This software was developed by Edward Tomasz Napierala under sponsorship
7  * from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following 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 AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 #include "opt_sched.h"
33 
34 #include <sys/param.h>
35 #include <sys/buf.h>
36 #include <sys/systm.h>
37 #include <sys/eventhandler.h>
38 #include <sys/jail.h>
39 #include <sys/kernel.h>
40 #include <sys/kthread.h>
41 #include <sys/lock.h>
42 #include <sys/loginclass.h>
43 #include <sys/malloc.h>
44 #include <sys/mutex.h>
45 #include <sys/proc.h>
46 #include <sys/racct.h>
47 #include <sys/resourcevar.h>
48 #include <sys/sbuf.h>
49 #include <sys/sched.h>
50 #include <sys/sdt.h>
51 #include <sys/smp.h>
52 #include <sys/sx.h>
53 #include <sys/sysctl.h>
54 #include <sys/sysproto.h>
55 #include <sys/umtxvar.h>
56 #include <machine/smp.h>
57 
58 #ifdef RCTL
59 #include <sys/rctl.h>
60 #endif
61 
62 FEATURE(racct, "Resource Accounting");
63 
64 /*
65  * Do not block processes that have their %cpu usage <= pcpu_threshold.
66  */
67 static int pcpu_threshold = 1;
68 #ifdef RACCT_DEFAULT_TO_DISABLED
69 bool __read_frequently racct_enable = false;
70 #else
71 bool __read_frequently racct_enable = true;
72 #endif
73 
74 SYSCTL_NODE(_kern, OID_AUTO, racct, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
75     "Resource Accounting");
76 SYSCTL_BOOL(_kern_racct, OID_AUTO, enable, CTLFLAG_RDTUN, &racct_enable,
77     0, "Enable RACCT/RCTL");
78 SYSCTL_UINT(_kern_racct, OID_AUTO, pcpu_threshold, CTLFLAG_RW, &pcpu_threshold,
79     0, "Processes with higher %cpu usage than this value can be throttled.");
80 
81 /*
82  * How many seconds it takes to use the scheduler %cpu calculations.  When a
83  * process starts, we compute its %cpu usage by dividing its runtime by the
84  * process wall clock time.  After RACCT_PCPU_SECS pass, we use the value
85  * provided by the scheduler.
86  */
87 #define RACCT_PCPU_SECS		3
88 
89 struct mtx racct_lock;
90 MTX_SYSINIT(racct_lock, &racct_lock, "racct lock", MTX_DEF);
91 
92 static uma_zone_t racct_zone;
93 
94 static void racct_sub_racct(struct racct *dest, const struct racct *src);
95 static void racct_sub_cred_locked(struct ucred *cred, int resource,
96 		uint64_t amount);
97 static void racct_add_cred_locked(struct ucred *cred, int resource,
98 		uint64_t amount);
99 
100 SDT_PROVIDER_DEFINE(racct);
101 SDT_PROBE_DEFINE3(racct, , rusage, add,
102     "struct proc *", "int", "uint64_t");
103 SDT_PROBE_DEFINE3(racct, , rusage, add__failure,
104     "struct proc *", "int", "uint64_t");
105 SDT_PROBE_DEFINE3(racct, , rusage, add__buf,
106     "struct proc *", "const struct buf *", "int");
107 SDT_PROBE_DEFINE3(racct, , rusage, add__cred,
108     "struct ucred *", "int", "uint64_t");
109 SDT_PROBE_DEFINE3(racct, , rusage, add__force,
110     "struct proc *", "int", "uint64_t");
111 SDT_PROBE_DEFINE3(racct, , rusage, set,
112     "struct proc *", "int", "uint64_t");
113 SDT_PROBE_DEFINE3(racct, , rusage, set__failure,
114     "struct proc *", "int", "uint64_t");
115 SDT_PROBE_DEFINE3(racct, , rusage, set__force,
116     "struct proc *", "int", "uint64_t");
117 SDT_PROBE_DEFINE3(racct, , rusage, sub,
118     "struct proc *", "int", "uint64_t");
119 SDT_PROBE_DEFINE3(racct, , rusage, sub__cred,
120     "struct ucred *", "int", "uint64_t");
121 SDT_PROBE_DEFINE1(racct, , racct, create,
122     "struct racct *");
123 SDT_PROBE_DEFINE1(racct, , racct, destroy,
124     "struct racct *");
125 SDT_PROBE_DEFINE2(racct, , racct, join,
126     "struct racct *", "struct racct *");
127 SDT_PROBE_DEFINE2(racct, , racct, join__failure,
128     "struct racct *", "struct racct *");
129 SDT_PROBE_DEFINE2(racct, , racct, leave,
130     "struct racct *", "struct racct *");
131 
132 int racct_types[] = {
133 	[RACCT_CPU] =
134 		RACCT_IN_MILLIONS,
135 	[RACCT_DATA] =
136 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
137 	[RACCT_STACK] =
138 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
139 	[RACCT_CORE] =
140 		RACCT_DENIABLE,
141 	[RACCT_RSS] =
142 		RACCT_RECLAIMABLE,
143 	[RACCT_MEMLOCK] =
144 		RACCT_RECLAIMABLE | RACCT_DENIABLE,
145 	[RACCT_NPROC] =
146 		RACCT_RECLAIMABLE | RACCT_DENIABLE,
147 	[RACCT_NOFILE] =
148 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
149 	[RACCT_VMEM] =
150 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
151 	[RACCT_NPTS] =
152 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
153 	[RACCT_SWAP] =
154 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
155 	[RACCT_NTHR] =
156 		RACCT_RECLAIMABLE | RACCT_DENIABLE,
157 	[RACCT_MSGQQUEUED] =
158 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
159 	[RACCT_MSGQSIZE] =
160 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
161 	[RACCT_NMSGQ] =
162 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
163 	[RACCT_NSEM] =
164 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
165 	[RACCT_NSEMOP] =
166 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
167 	[RACCT_NSHM] =
168 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
169 	[RACCT_SHMSIZE] =
170 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
171 	[RACCT_WALLCLOCK] =
172 		RACCT_IN_MILLIONS,
173 	[RACCT_PCTCPU] =
174 		RACCT_DECAYING | RACCT_DENIABLE | RACCT_IN_MILLIONS,
175 	[RACCT_READBPS] =
176 		RACCT_DECAYING,
177 	[RACCT_WRITEBPS] =
178 		RACCT_DECAYING,
179 	[RACCT_READIOPS] =
180 		RACCT_DECAYING,
181 	[RACCT_WRITEIOPS] =
182 		RACCT_DECAYING };
183 
184 static const fixpt_t RACCT_DECAY_FACTOR = 0.3 * FSCALE;
185 
186 #ifdef SCHED_4BSD
187 /*
188  * Contains intermediate values for %cpu calculations to avoid using floating
189  * point in the kernel.
190  * ccpu_exp[k] = FSCALE * (ccpu/FSCALE)^k = FSCALE * exp(-k/20)
191  * It is needed only for the 4BSD scheduler, because in ULE, the ccpu equals to
192  * zero so the calculations are more straightforward.
193  */
194 fixpt_t ccpu_exp[] = {
195 	[0] = FSCALE * 1,
196 	[1] = FSCALE * 0.95122942450071400909,
197 	[2] = FSCALE * 0.90483741803595957316,
198 	[3] = FSCALE * 0.86070797642505780722,
199 	[4] = FSCALE * 0.81873075307798185866,
200 	[5] = FSCALE * 0.77880078307140486824,
201 	[6] = FSCALE * 0.74081822068171786606,
202 	[7] = FSCALE * 0.70468808971871343435,
203 	[8] = FSCALE * 0.67032004603563930074,
204 	[9] = FSCALE * 0.63762815162177329314,
205 	[10] = FSCALE * 0.60653065971263342360,
206 	[11] = FSCALE * 0.57694981038048669531,
207 	[12] = FSCALE * 0.54881163609402643262,
208 	[13] = FSCALE * 0.52204577676101604789,
209 	[14] = FSCALE * 0.49658530379140951470,
210 	[15] = FSCALE * 0.47236655274101470713,
211 	[16] = FSCALE * 0.44932896411722159143,
212 	[17] = FSCALE * 0.42741493194872666992,
213 	[18] = FSCALE * 0.40656965974059911188,
214 	[19] = FSCALE * 0.38674102345450120691,
215 	[20] = FSCALE * 0.36787944117144232159,
216 	[21] = FSCALE * 0.34993774911115535467,
217 	[22] = FSCALE * 0.33287108369807955328,
218 	[23] = FSCALE * 0.31663676937905321821,
219 	[24] = FSCALE * 0.30119421191220209664,
220 	[25] = FSCALE * 0.28650479686019010032,
221 	[26] = FSCALE * 0.27253179303401260312,
222 	[27] = FSCALE * 0.25924026064589150757,
223 	[28] = FSCALE * 0.24659696394160647693,
224 	[29] = FSCALE * 0.23457028809379765313,
225 	[30] = FSCALE * 0.22313016014842982893,
226 	[31] = FSCALE * 0.21224797382674305771,
227 	[32] = FSCALE * 0.20189651799465540848,
228 	[33] = FSCALE * 0.19204990862075411423,
229 	[34] = FSCALE * 0.18268352405273465022,
230 	[35] = FSCALE * 0.17377394345044512668,
231 	[36] = FSCALE * 0.16529888822158653829,
232 	[37] = FSCALE * 0.15723716631362761621,
233 	[38] = FSCALE * 0.14956861922263505264,
234 	[39] = FSCALE * 0.14227407158651357185,
235 	[40] = FSCALE * 0.13533528323661269189,
236 	[41] = FSCALE * 0.12873490358780421886,
237 	[42] = FSCALE * 0.12245642825298191021,
238 	[43] = FSCALE * 0.11648415777349695786,
239 	[44] = FSCALE * 0.11080315836233388333,
240 	[45] = FSCALE * 0.10539922456186433678,
241 	[46] = FSCALE * 0.10025884372280373372,
242 	[47] = FSCALE * 0.09536916221554961888,
243 	[48] = FSCALE * 0.09071795328941250337,
244 	[49] = FSCALE * 0.08629358649937051097,
245 	[50] = FSCALE * 0.08208499862389879516,
246 	[51] = FSCALE * 0.07808166600115315231,
247 	[52] = FSCALE * 0.07427357821433388042,
248 	[53] = FSCALE * 0.07065121306042958674,
249 	[54] = FSCALE * 0.06720551273974976512,
250 	[55] = FSCALE * 0.06392786120670757270,
251 	[56] = FSCALE * 0.06081006262521796499,
252 	[57] = FSCALE * 0.05784432087483846296,
253 	[58] = FSCALE * 0.05502322005640722902,
254 	[59] = FSCALE * 0.05233970594843239308,
255 	[60] = FSCALE * 0.04978706836786394297,
256 	[61] = FSCALE * 0.04735892439114092119,
257 	[62] = FSCALE * 0.04504920239355780606,
258 	[63] = FSCALE * 0.04285212686704017991,
259 	[64] = FSCALE * 0.04076220397836621516,
260 	[65] = FSCALE * 0.03877420783172200988,
261 	[66] = FSCALE * 0.03688316740124000544,
262 	[67] = FSCALE * 0.03508435410084502588,
263 	[68] = FSCALE * 0.03337326996032607948,
264 	[69] = FSCALE * 0.03174563637806794323,
265 	[70] = FSCALE * 0.03019738342231850073,
266 	[71] = FSCALE * 0.02872463965423942912,
267 	[72] = FSCALE * 0.02732372244729256080,
268 	[73] = FSCALE * 0.02599112877875534358,
269 	[74] = FSCALE * 0.02472352647033939120,
270 	[75] = FSCALE * 0.02351774585600910823,
271 	[76] = FSCALE * 0.02237077185616559577,
272 	[77] = FSCALE * 0.02127973643837716938,
273 	[78] = FSCALE * 0.02024191144580438847,
274 	[79] = FSCALE * 0.01925470177538692429,
275 	[80] = FSCALE * 0.01831563888873418029,
276 	[81] = FSCALE * 0.01742237463949351138,
277 	[82] = FSCALE * 0.01657267540176124754,
278 	[83] = FSCALE * 0.01576441648485449082,
279 	[84] = FSCALE * 0.01499557682047770621,
280 	[85] = FSCALE * 0.01426423390899925527,
281 	[86] = FSCALE * 0.01356855901220093175,
282 	[87] = FSCALE * 0.01290681258047986886,
283 	[88] = FSCALE * 0.01227733990306844117,
284 	[89] = FSCALE * 0.01167856697039544521,
285 	[90] = FSCALE * 0.01110899653824230649,
286 	[91] = FSCALE * 0.01056720438385265337,
287 	[92] = FSCALE * 0.01005183574463358164,
288 	[93] = FSCALE * 0.00956160193054350793,
289 	[94] = FSCALE * 0.00909527710169581709,
290 	[95] = FSCALE * 0.00865169520312063417,
291 	[96] = FSCALE * 0.00822974704902002884,
292 	[97] = FSCALE * 0.00782837754922577143,
293 	[98] = FSCALE * 0.00744658307092434051,
294 	[99] = FSCALE * 0.00708340892905212004,
295 	[100] = FSCALE * 0.00673794699908546709,
296 	[101] = FSCALE * 0.00640933344625638184,
297 	[102] = FSCALE * 0.00609674656551563610,
298 	[103] = FSCALE * 0.00579940472684214321,
299 	[104] = FSCALE * 0.00551656442076077241,
300 	[105] = FSCALE * 0.00524751839918138427,
301 	[106] = FSCALE * 0.00499159390691021621,
302 	[107] = FSCALE * 0.00474815099941147558,
303 	[108] = FSCALE * 0.00451658094261266798,
304 	[109] = FSCALE * 0.00429630469075234057,
305 	[110] = FSCALE * 0.00408677143846406699,
306 };
307 #endif
308 
309 #define	CCPU_EXP_MAX	110
310 
311 /*
312  * This function is analogical to the getpcpu() function in the ps(1) command.
313  * They should both calculate in the same way so that the racct %cpu
314  * calculations are consistent with the values showed by the ps(1) tool.
315  * The calculations are more complex in the 4BSD scheduler because of the value
316  * of the ccpu variable.  In ULE it is defined to be zero which saves us some
317  * work.
318  */
319 static uint64_t
320 racct_getpcpu(struct proc *p, u_int pcpu)
321 {
322 	u_int swtime;
323 #ifdef SCHED_4BSD
324 	fixpt_t pctcpu, pctcpu_next;
325 #endif
326 #ifdef SMP
327 	struct pcpu *pc;
328 	int found;
329 #endif
330 	fixpt_t p_pctcpu;
331 	struct thread *td;
332 
333 	ASSERT_RACCT_ENABLED();
334 
335 	swtime = (ticks - p->p_swtick) / hz;
336 
337 	/*
338 	 * For short-lived processes, the sched_pctcpu() returns small
339 	 * values even for cpu intensive processes.  Therefore we use
340 	 * our own estimate in this case.
341 	 */
342 	if (swtime < RACCT_PCPU_SECS)
343 		return (pcpu);
344 
345 	p_pctcpu = 0;
346 	FOREACH_THREAD_IN_PROC(p, td) {
347 		if (td == PCPU_GET(idlethread))
348 			continue;
349 #ifdef SMP
350 		found = 0;
351 		STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
352 			if (td == pc->pc_idlethread) {
353 				found = 1;
354 				break;
355 			}
356 		}
357 		if (found)
358 			continue;
359 #endif
360 		thread_lock(td);
361 #ifdef SCHED_4BSD
362 		pctcpu = sched_pctcpu(td);
363 		/* Count also the yet unfinished second. */
364 		pctcpu_next = (pctcpu * ccpu_exp[1]) >> FSHIFT;
365 		pctcpu_next += sched_pctcpu_delta(td);
366 		p_pctcpu += max(pctcpu, pctcpu_next);
367 #else
368 		/*
369 		 * In ULE the %cpu statistics are updated on every
370 		 * sched_pctcpu() call.  So special calculations to
371 		 * account for the latest (unfinished) second are
372 		 * not needed.
373 		 */
374 		p_pctcpu += sched_pctcpu(td);
375 #endif
376 		thread_unlock(td);
377 	}
378 
379 #ifdef SCHED_4BSD
380 	if (swtime <= CCPU_EXP_MAX)
381 		return ((100 * (uint64_t)p_pctcpu * 1000000) /
382 		    (FSCALE - ccpu_exp[swtime]));
383 #endif
384 
385 	return ((100 * (uint64_t)p_pctcpu * 1000000) / FSCALE);
386 }
387 
388 static void
389 racct_add_racct(struct racct *dest, const struct racct *src)
390 {
391 	int i;
392 
393 	ASSERT_RACCT_ENABLED();
394 	RACCT_LOCK_ASSERT();
395 
396 	/*
397 	 * Update resource usage in dest.
398 	 */
399 	for (i = 0; i <= RACCT_MAX; i++) {
400 		KASSERT(dest->r_resources[i] >= 0,
401 		    ("%s: resource %d propagation meltdown: dest < 0",
402 		    __func__, i));
403 		KASSERT(src->r_resources[i] >= 0,
404 		    ("%s: resource %d propagation meltdown: src < 0",
405 		    __func__, i));
406 		dest->r_resources[i] += src->r_resources[i];
407 	}
408 }
409 
410 static void
411 racct_sub_racct(struct racct *dest, const struct racct *src)
412 {
413 	int i;
414 
415 	ASSERT_RACCT_ENABLED();
416 	RACCT_LOCK_ASSERT();
417 
418 	/*
419 	 * Update resource usage in dest.
420 	 */
421 	for (i = 0; i <= RACCT_MAX; i++) {
422 		if (!RACCT_IS_SLOPPY(i) && !RACCT_IS_DECAYING(i)) {
423 			KASSERT(dest->r_resources[i] >= 0,
424 			    ("%s: resource %d propagation meltdown: dest < 0",
425 			    __func__, i));
426 			KASSERT(src->r_resources[i] >= 0,
427 			    ("%s: resource %d propagation meltdown: src < 0",
428 			    __func__, i));
429 			KASSERT(src->r_resources[i] <= dest->r_resources[i],
430 			    ("%s: resource %d propagation meltdown: src > dest",
431 			    __func__, i));
432 		}
433 		if (RACCT_CAN_DROP(i)) {
434 			dest->r_resources[i] -= src->r_resources[i];
435 			if (dest->r_resources[i] < 0)
436 				dest->r_resources[i] = 0;
437 		}
438 	}
439 }
440 
441 void
442 racct_create(struct racct **racctp)
443 {
444 
445 	if (!racct_enable)
446 		return;
447 
448 	SDT_PROBE1(racct, , racct, create, racctp);
449 
450 	KASSERT(*racctp == NULL, ("racct already allocated"));
451 
452 	*racctp = uma_zalloc(racct_zone, M_WAITOK | M_ZERO);
453 }
454 
455 static void
456 racct_destroy_locked(struct racct **racctp)
457 {
458 	struct racct *racct;
459 	int i;
460 
461 	ASSERT_RACCT_ENABLED();
462 
463 	SDT_PROBE1(racct, , racct, destroy, racctp);
464 
465 	RACCT_LOCK_ASSERT();
466 	KASSERT(racctp != NULL, ("NULL racctp"));
467 	KASSERT(*racctp != NULL, ("NULL racct"));
468 
469 	racct = *racctp;
470 
471 	for (i = 0; i <= RACCT_MAX; i++) {
472 		if (RACCT_IS_SLOPPY(i))
473 			continue;
474 		if (!RACCT_IS_RECLAIMABLE(i))
475 			continue;
476 		KASSERT(racct->r_resources[i] == 0,
477 		    ("destroying non-empty racct: "
478 		    "%ju allocated for resource %d\n",
479 		    racct->r_resources[i], i));
480 	}
481 	uma_zfree(racct_zone, racct);
482 	*racctp = NULL;
483 }
484 
485 void
486 racct_destroy(struct racct **racct)
487 {
488 
489 	if (!racct_enable)
490 		return;
491 
492 	RACCT_LOCK();
493 	racct_destroy_locked(racct);
494 	RACCT_UNLOCK();
495 }
496 
497 /*
498  * Increase consumption of 'resource' by 'amount' for 'racct',
499  * but not its parents.  Differently from other cases, 'amount' here
500  * may be less than zero.
501  */
502 static void
503 racct_adjust_resource(struct racct *racct, int resource,
504     int64_t amount)
505 {
506 
507 	ASSERT_RACCT_ENABLED();
508 	RACCT_LOCK_ASSERT();
509 	KASSERT(racct != NULL, ("NULL racct"));
510 
511 	racct->r_resources[resource] += amount;
512 	if (racct->r_resources[resource] < 0) {
513 		KASSERT(RACCT_IS_SLOPPY(resource) || RACCT_IS_DECAYING(resource),
514 		    ("%s: resource %d usage < 0", __func__, resource));
515 		racct->r_resources[resource] = 0;
516 	}
517 
518 	/*
519 	 * There are some cases where the racct %cpu resource would grow
520 	 * beyond 100% per core.  For example in racct_proc_exit() we add
521 	 * the process %cpu usage to the ucred racct containers.  If too
522 	 * many processes terminated in a short time span, the ucred %cpu
523 	 * resource could grow too much.  Also, the 4BSD scheduler sometimes
524 	 * returns for a thread more than 100% cpu usage. So we set a sane
525 	 * boundary here to 100% * the maximum number of CPUs.
526 	 */
527 	if ((resource == RACCT_PCTCPU) &&
528 	    (racct->r_resources[RACCT_PCTCPU] > 100 * 1000000 * (int64_t)MAXCPU))
529 		racct->r_resources[RACCT_PCTCPU] = 100 * 1000000 * (int64_t)MAXCPU;
530 }
531 
532 static int
533 racct_add_locked(struct proc *p, int resource, uint64_t amount, int force)
534 {
535 #ifdef RCTL
536 	int error;
537 #endif
538 
539 	ASSERT_RACCT_ENABLED();
540 
541 	/*
542 	 * We need proc lock to dereference p->p_ucred.
543 	 */
544 	PROC_LOCK_ASSERT(p, MA_OWNED);
545 
546 #ifdef RCTL
547 	error = rctl_enforce(p, resource, amount);
548 	if (error && !force && RACCT_IS_DENIABLE(resource)) {
549 		SDT_PROBE3(racct, , rusage, add__failure, p, resource, amount);
550 		return (error);
551 	}
552 #endif
553 	racct_adjust_resource(p->p_racct, resource, amount);
554 	racct_add_cred_locked(p->p_ucred, resource, amount);
555 
556 	return (0);
557 }
558 
559 /*
560  * Increase allocation of 'resource' by 'amount' for process 'p'.
561  * Return 0 if it's below limits, or errno, if it's not.
562  */
563 int
564 racct_add(struct proc *p, int resource, uint64_t amount)
565 {
566 	int error;
567 
568 	if (!racct_enable)
569 		return (0);
570 
571 	SDT_PROBE3(racct, , rusage, add, p, resource, amount);
572 
573 	RACCT_LOCK();
574 	error = racct_add_locked(p, resource, amount, 0);
575 	RACCT_UNLOCK();
576 	return (error);
577 }
578 
579 /*
580  * Increase allocation of 'resource' by 'amount' for process 'p'.
581  * Doesn't check for limits and never fails.
582  */
583 void
584 racct_add_force(struct proc *p, int resource, uint64_t amount)
585 {
586 
587 	if (!racct_enable)
588 		return;
589 
590 	SDT_PROBE3(racct, , rusage, add__force, p, resource, amount);
591 
592 	RACCT_LOCK();
593 	racct_add_locked(p, resource, amount, 1);
594 	RACCT_UNLOCK();
595 }
596 
597 static void
598 racct_add_cred_locked(struct ucred *cred, int resource, uint64_t amount)
599 {
600 	struct prison *pr;
601 
602 	ASSERT_RACCT_ENABLED();
603 
604 	racct_adjust_resource(cred->cr_ruidinfo->ui_racct, resource, amount);
605 	for (pr = cred->cr_prison; pr != NULL; pr = pr->pr_parent)
606 		racct_adjust_resource(pr->pr_prison_racct->prr_racct, resource,
607 		    amount);
608 	racct_adjust_resource(cred->cr_loginclass->lc_racct, resource, amount);
609 }
610 
611 /*
612  * Increase allocation of 'resource' by 'amount' for credential 'cred'.
613  * Doesn't check for limits and never fails.
614  */
615 void
616 racct_add_cred(struct ucred *cred, int resource, uint64_t amount)
617 {
618 
619 	if (!racct_enable)
620 		return;
621 
622 	SDT_PROBE3(racct, , rusage, add__cred, cred, resource, amount);
623 
624 	RACCT_LOCK();
625 	racct_add_cred_locked(cred, resource, amount);
626 	RACCT_UNLOCK();
627 }
628 
629 /*
630  * Account for disk IO resource consumption.  Checks for limits,
631  * but never fails, due to disk limits being undeniable.
632  */
633 void
634 racct_add_buf(struct proc *p, const struct buf *bp, int is_write)
635 {
636 
637 	ASSERT_RACCT_ENABLED();
638 	PROC_LOCK_ASSERT(p, MA_OWNED);
639 
640 	SDT_PROBE3(racct, , rusage, add__buf, p, bp, is_write);
641 
642 	RACCT_LOCK();
643 	if (is_write) {
644 		racct_add_locked(curproc, RACCT_WRITEBPS, bp->b_bcount, 1);
645 		racct_add_locked(curproc, RACCT_WRITEIOPS, 1, 1);
646 	} else {
647 		racct_add_locked(curproc, RACCT_READBPS, bp->b_bcount, 1);
648 		racct_add_locked(curproc, RACCT_READIOPS, 1, 1);
649 	}
650 	RACCT_UNLOCK();
651 }
652 
653 static int
654 racct_set_locked(struct proc *p, int resource, uint64_t amount, int force)
655 {
656 	int64_t old_amount, decayed_amount, diff_proc, diff_cred;
657 #ifdef RCTL
658 	int error;
659 #endif
660 
661 	ASSERT_RACCT_ENABLED();
662 
663 	/*
664 	 * We need proc lock to dereference p->p_ucred.
665 	 */
666 	PROC_LOCK_ASSERT(p, MA_OWNED);
667 
668 	old_amount = p->p_racct->r_resources[resource];
669 	/*
670 	 * The diffs may be negative.
671 	 */
672 	diff_proc = amount - old_amount;
673 	if (resource == RACCT_PCTCPU) {
674 		/*
675 		 * Resources in per-credential racct containers may decay.
676 		 * If this is the case, we need to calculate the difference
677 		 * between the new amount and the proportional value of the
678 		 * old amount that has decayed in the ucred racct containers.
679 		 */
680 		decayed_amount = old_amount * RACCT_DECAY_FACTOR / FSCALE;
681 		diff_cred = amount - decayed_amount;
682 	} else
683 		diff_cred = diff_proc;
684 #ifdef notyet
685 	KASSERT(diff_proc >= 0 || RACCT_CAN_DROP(resource),
686 	    ("%s: usage of non-droppable resource %d dropping", __func__,
687 	     resource));
688 #endif
689 #ifdef RCTL
690 	if (diff_proc > 0) {
691 		error = rctl_enforce(p, resource, diff_proc);
692 		if (error && !force && RACCT_IS_DENIABLE(resource)) {
693 			SDT_PROBE3(racct, , rusage, set__failure, p, resource,
694 			    amount);
695 			return (error);
696 		}
697 	}
698 #endif
699 	racct_adjust_resource(p->p_racct, resource, diff_proc);
700 	if (diff_cred > 0)
701 		racct_add_cred_locked(p->p_ucred, resource, diff_cred);
702 	else if (diff_cred < 0)
703 		racct_sub_cred_locked(p->p_ucred, resource, -diff_cred);
704 
705 	return (0);
706 }
707 
708 /*
709  * Set allocation of 'resource' to 'amount' for process 'p'.
710  * Return 0 if it's below limits, or errno, if it's not.
711  *
712  * Note that decreasing the allocation always returns 0,
713  * even if it's above the limit.
714  */
715 int
716 racct_set_unlocked(struct proc *p, int resource, uint64_t amount)
717 {
718 	int error;
719 
720 	ASSERT_RACCT_ENABLED();
721 	PROC_LOCK(p);
722 	error = racct_set(p, resource, amount);
723 	PROC_UNLOCK(p);
724 	return (error);
725 }
726 
727 int
728 racct_set(struct proc *p, int resource, uint64_t amount)
729 {
730 	int error;
731 
732 	if (!racct_enable)
733 		return (0);
734 
735 	SDT_PROBE3(racct, , rusage, set__force, p, resource, amount);
736 
737 	RACCT_LOCK();
738 	error = racct_set_locked(p, resource, amount, 0);
739 	RACCT_UNLOCK();
740 	return (error);
741 }
742 
743 void
744 racct_set_force(struct proc *p, int resource, uint64_t amount)
745 {
746 
747 	if (!racct_enable)
748 		return;
749 
750 	SDT_PROBE3(racct, , rusage, set, p, resource, amount);
751 
752 	RACCT_LOCK();
753 	racct_set_locked(p, resource, amount, 1);
754 	RACCT_UNLOCK();
755 }
756 
757 /*
758  * Returns amount of 'resource' the process 'p' can keep allocated.
759  * Allocating more than that would be denied, unless the resource
760  * is marked undeniable.  Amount of already allocated resource does
761  * not matter.
762  */
763 uint64_t
764 racct_get_limit(struct proc *p, int resource)
765 {
766 #ifdef RCTL
767 	uint64_t available;
768 
769 	if (!racct_enable)
770 		return (UINT64_MAX);
771 
772 	RACCT_LOCK();
773 	available = rctl_get_limit(p, resource);
774 	RACCT_UNLOCK();
775 
776 	return (available);
777 #else
778 
779 	return (UINT64_MAX);
780 #endif
781 }
782 
783 /*
784  * Returns amount of 'resource' the process 'p' can keep allocated.
785  * Allocating more than that would be denied, unless the resource
786  * is marked undeniable.  Amount of already allocated resource does
787  * matter.
788  */
789 uint64_t
790 racct_get_available(struct proc *p, int resource)
791 {
792 #ifdef RCTL
793 	uint64_t available;
794 
795 	if (!racct_enable)
796 		return (UINT64_MAX);
797 
798 	RACCT_LOCK();
799 	available = rctl_get_available(p, resource);
800 	RACCT_UNLOCK();
801 
802 	return (available);
803 #else
804 
805 	return (UINT64_MAX);
806 #endif
807 }
808 
809 /*
810  * Returns amount of the %cpu resource that process 'p' can add to its %cpu
811  * utilization.  Adding more than that would lead to the process being
812  * throttled.
813  */
814 static int64_t
815 racct_pcpu_available(struct proc *p)
816 {
817 #ifdef RCTL
818 	uint64_t available;
819 
820 	ASSERT_RACCT_ENABLED();
821 
822 	RACCT_LOCK();
823 	available = rctl_pcpu_available(p);
824 	RACCT_UNLOCK();
825 
826 	return (available);
827 #else
828 
829 	return (INT64_MAX);
830 #endif
831 }
832 
833 /*
834  * Decrease allocation of 'resource' by 'amount' for process 'p'.
835  */
836 void
837 racct_sub(struct proc *p, int resource, uint64_t amount)
838 {
839 
840 	if (!racct_enable)
841 		return;
842 
843 	SDT_PROBE3(racct, , rusage, sub, p, resource, amount);
844 
845 	/*
846 	 * We need proc lock to dereference p->p_ucred.
847 	 */
848 	PROC_LOCK_ASSERT(p, MA_OWNED);
849 	KASSERT(RACCT_CAN_DROP(resource),
850 	    ("%s: called for non-droppable resource %d", __func__, resource));
851 
852 	RACCT_LOCK();
853 	KASSERT(amount <= p->p_racct->r_resources[resource],
854 	    ("%s: freeing %ju of resource %d, which is more "
855 	     "than allocated %jd for %s (pid %d)", __func__, amount, resource,
856 	    (intmax_t)p->p_racct->r_resources[resource], p->p_comm, p->p_pid));
857 
858 	racct_adjust_resource(p->p_racct, resource, -amount);
859 	racct_sub_cred_locked(p->p_ucred, resource, amount);
860 	RACCT_UNLOCK();
861 }
862 
863 static void
864 racct_sub_cred_locked(struct ucred *cred, int resource, uint64_t amount)
865 {
866 	struct prison *pr;
867 
868 	ASSERT_RACCT_ENABLED();
869 
870 	racct_adjust_resource(cred->cr_ruidinfo->ui_racct, resource, -amount);
871 	for (pr = cred->cr_prison; pr != NULL; pr = pr->pr_parent)
872 		racct_adjust_resource(pr->pr_prison_racct->prr_racct, resource,
873 		    -amount);
874 	racct_adjust_resource(cred->cr_loginclass->lc_racct, resource, -amount);
875 }
876 
877 /*
878  * Decrease allocation of 'resource' by 'amount' for credential 'cred'.
879  */
880 void
881 racct_sub_cred(struct ucred *cred, int resource, uint64_t amount)
882 {
883 
884 	if (!racct_enable)
885 		return;
886 
887 	SDT_PROBE3(racct, , rusage, sub__cred, cred, resource, amount);
888 
889 #ifdef notyet
890 	KASSERT(RACCT_CAN_DROP(resource),
891 	    ("%s: called for resource %d which can not drop", __func__,
892 	     resource));
893 #endif
894 
895 	RACCT_LOCK();
896 	racct_sub_cred_locked(cred, resource, amount);
897 	RACCT_UNLOCK();
898 }
899 
900 /*
901  * Inherit resource usage information from the parent process.
902  */
903 int
904 racct_proc_fork(struct proc *parent, struct proc *child)
905 {
906 	int i, error = 0;
907 
908 	if (!racct_enable)
909 		return (0);
910 
911 	/*
912 	 * Create racct for the child process.
913 	 */
914 	racct_create(&child->p_racct);
915 
916 	PROC_LOCK(parent);
917 	PROC_LOCK(child);
918 	RACCT_LOCK();
919 
920 #ifdef RCTL
921 	error = rctl_proc_fork(parent, child);
922 	if (error != 0)
923 		goto out;
924 #endif
925 
926 	/* Init process cpu time. */
927 	child->p_prev_runtime = 0;
928 	child->p_throttled = 0;
929 
930 	/*
931 	 * Inherit resource usage.
932 	 */
933 	for (i = 0; i <= RACCT_MAX; i++) {
934 		if (parent->p_racct->r_resources[i] == 0 ||
935 		    !RACCT_IS_INHERITABLE(i))
936 			continue;
937 
938 		error = racct_set_locked(child, i,
939 		    parent->p_racct->r_resources[i], 0);
940 		if (error != 0)
941 			goto out;
942 	}
943 
944 	error = racct_add_locked(child, RACCT_NPROC, 1, 0);
945 	error += racct_add_locked(child, RACCT_NTHR, 1, 0);
946 
947 out:
948 	RACCT_UNLOCK();
949 	PROC_UNLOCK(child);
950 	PROC_UNLOCK(parent);
951 
952 	if (error != 0)
953 		racct_proc_exit(child);
954 
955 	return (error);
956 }
957 
958 /*
959  * Called at the end of fork1(), to handle rules that require the process
960  * to be fully initialized.
961  */
962 void
963 racct_proc_fork_done(struct proc *child)
964 {
965 
966 	if (!racct_enable)
967 		return;
968 
969 #ifdef RCTL
970 	PROC_LOCK(child);
971 	RACCT_LOCK();
972 	rctl_enforce(child, RACCT_NPROC, 0);
973 	rctl_enforce(child, RACCT_NTHR, 0);
974 	RACCT_UNLOCK();
975 	PROC_UNLOCK(child);
976 #endif
977 }
978 
979 void
980 racct_proc_exit(struct proc *p)
981 {
982 	struct timeval wallclock;
983 	uint64_t pct_estimate, pct, runtime;
984 	int i;
985 
986 	if (!racct_enable)
987 		return;
988 
989 	PROC_LOCK(p);
990 	/*
991 	 * We don't need to calculate rux, proc_reap() has already done this.
992 	 */
993 	runtime = cputick2usec(p->p_rux.rux_runtime);
994 #ifdef notyet
995 	KASSERT(runtime >= p->p_prev_runtime, ("runtime < p_prev_runtime"));
996 #else
997 	if (runtime < p->p_prev_runtime)
998 		runtime = p->p_prev_runtime;
999 #endif
1000 	microuptime(&wallclock);
1001 	timevalsub(&wallclock, &p->p_stats->p_start);
1002 	if (wallclock.tv_sec > 0 || wallclock.tv_usec > 0) {
1003 		pct_estimate = (1000000 * runtime * 100) /
1004 		    ((uint64_t)wallclock.tv_sec * 1000000 +
1005 		    wallclock.tv_usec);
1006 	} else
1007 		pct_estimate = 0;
1008 	pct = racct_getpcpu(p, pct_estimate);
1009 
1010 	RACCT_LOCK();
1011 	racct_set_locked(p, RACCT_CPU, runtime, 0);
1012 	racct_add_cred_locked(p->p_ucred, RACCT_PCTCPU, pct);
1013 
1014 	KASSERT(p->p_racct->r_resources[RACCT_RSS] == 0,
1015 	    ("process reaped with %ju allocated for RSS\n",
1016 	    p->p_racct->r_resources[RACCT_RSS]));
1017 	for (i = 0; i <= RACCT_MAX; i++) {
1018 		if (p->p_racct->r_resources[i] == 0)
1019 			continue;
1020 		if (!RACCT_IS_RECLAIMABLE(i))
1021 			continue;
1022 		racct_set_locked(p, i, 0, 0);
1023 	}
1024 
1025 #ifdef RCTL
1026 	rctl_racct_release(p->p_racct);
1027 #endif
1028 	racct_destroy_locked(&p->p_racct);
1029 	RACCT_UNLOCK();
1030 	PROC_UNLOCK(p);
1031 }
1032 
1033 /*
1034  * Called after credentials change, to move resource utilisation
1035  * between raccts.
1036  */
1037 void
1038 racct_proc_ucred_changed(struct proc *p, struct ucred *oldcred,
1039     struct ucred *newcred)
1040 {
1041 	struct uidinfo *olduip, *newuip;
1042 	struct loginclass *oldlc, *newlc;
1043 	struct prison *oldpr, *newpr, *pr;
1044 
1045 	if (!racct_enable)
1046 		return;
1047 
1048 	PROC_LOCK_ASSERT(p, MA_OWNED);
1049 
1050 	newuip = newcred->cr_ruidinfo;
1051 	olduip = oldcred->cr_ruidinfo;
1052 	newlc = newcred->cr_loginclass;
1053 	oldlc = oldcred->cr_loginclass;
1054 	newpr = newcred->cr_prison;
1055 	oldpr = oldcred->cr_prison;
1056 
1057 	RACCT_LOCK();
1058 	if (newuip != olduip) {
1059 		racct_sub_racct(olduip->ui_racct, p->p_racct);
1060 		racct_add_racct(newuip->ui_racct, p->p_racct);
1061 	}
1062 	if (newlc != oldlc) {
1063 		racct_sub_racct(oldlc->lc_racct, p->p_racct);
1064 		racct_add_racct(newlc->lc_racct, p->p_racct);
1065 	}
1066 	if (newpr != oldpr) {
1067 		for (pr = oldpr; pr != NULL; pr = pr->pr_parent)
1068 			racct_sub_racct(pr->pr_prison_racct->prr_racct,
1069 			    p->p_racct);
1070 		for (pr = newpr; pr != NULL; pr = pr->pr_parent)
1071 			racct_add_racct(pr->pr_prison_racct->prr_racct,
1072 			    p->p_racct);
1073 	}
1074 	RACCT_UNLOCK();
1075 }
1076 
1077 void
1078 racct_move(struct racct *dest, struct racct *src)
1079 {
1080 
1081 	ASSERT_RACCT_ENABLED();
1082 
1083 	RACCT_LOCK();
1084 	racct_add_racct(dest, src);
1085 	racct_sub_racct(src, src);
1086 	RACCT_UNLOCK();
1087 }
1088 
1089 static void
1090 ast_racct(struct thread *td, int tda __unused)
1091 {
1092 	struct proc *p;
1093 
1094 	ASSERT_RACCT_ENABLED();
1095 
1096 	p = td->td_proc;
1097 	if (p->p_throttled == 0)
1098 		return;
1099 
1100 	PROC_LOCK(p);
1101 	while (p->p_throttled != 0) {
1102 		msleep(p->p_racct, &p->p_mtx, 0, "racct",
1103 		    p->p_throttled < 0 ? 0 : p->p_throttled);
1104 		if (p->p_throttled > 0)
1105 			p->p_throttled = 0;
1106 	}
1107 	PROC_UNLOCK(p);
1108 }
1109 
1110 /*
1111  * Make the process sleep in userret() for 'timeout' ticks.  Setting
1112  * timeout to -1 makes it sleep until woken up by racct_proc_wakeup().
1113  */
1114 void
1115 racct_proc_throttle(struct proc *p, int timeout)
1116 {
1117 	struct thread *td;
1118 #ifdef SMP
1119 	int cpuid;
1120 #endif
1121 
1122 	KASSERT(timeout != 0, ("timeout %d", timeout));
1123 	ASSERT_RACCT_ENABLED();
1124 	PROC_LOCK_ASSERT(p, MA_OWNED);
1125 
1126 	/*
1127 	 * Do not block kernel processes.  Also do not block processes with
1128 	 * low %cpu utilization to improve interactivity.
1129 	 */
1130 	if ((p->p_flag & (P_SYSTEM | P_KPROC)) != 0)
1131 		return;
1132 
1133 	if (p->p_throttled < 0 || (timeout > 0 && p->p_throttled > timeout))
1134 		return;
1135 
1136 	p->p_throttled = timeout;
1137 
1138 	FOREACH_THREAD_IN_PROC(p, td) {
1139 		thread_lock(td);
1140 		ast_sched_locked(td, TDA_RACCT);
1141 
1142 		switch (TD_GET_STATE(td)) {
1143 		case TDS_RUNQ:
1144 			/*
1145 			 * If the thread is on the scheduler run-queue, we can
1146 			 * not just remove it from there.  So we set the flag
1147 			 * TDA_SCHED for the thread, so that once it is
1148 			 * running, it is taken off the cpu as soon as possible.
1149 			 */
1150 			ast_sched_locked(td, TDA_SCHED);
1151 			break;
1152 		case TDS_RUNNING:
1153 			/*
1154 			 * If the thread is running, we request a context
1155 			 * switch for it by setting the TDA_SCHED flag.
1156 			 */
1157 			ast_sched_locked(td, TDA_SCHED);
1158 #ifdef SMP
1159 			cpuid = td->td_oncpu;
1160 			if ((cpuid != NOCPU) && (td != curthread))
1161 				ipi_cpu(cpuid, IPI_AST);
1162 #endif
1163 			break;
1164 		default:
1165 			break;
1166 		}
1167 		thread_unlock(td);
1168 	}
1169 }
1170 
1171 static void
1172 racct_proc_wakeup(struct proc *p)
1173 {
1174 
1175 	ASSERT_RACCT_ENABLED();
1176 
1177 	PROC_LOCK_ASSERT(p, MA_OWNED);
1178 
1179 	if (p->p_throttled != 0) {
1180 		p->p_throttled = 0;
1181 		wakeup(p->p_racct);
1182 	}
1183 }
1184 
1185 static void
1186 racct_decay_callback(struct racct *racct, void *dummy1, void *dummy2)
1187 {
1188 	int64_t r_old, r_new;
1189 
1190 	ASSERT_RACCT_ENABLED();
1191 	RACCT_LOCK_ASSERT();
1192 
1193 #ifdef RCTL
1194 	rctl_throttle_decay(racct, RACCT_READBPS);
1195 	rctl_throttle_decay(racct, RACCT_WRITEBPS);
1196 	rctl_throttle_decay(racct, RACCT_READIOPS);
1197 	rctl_throttle_decay(racct, RACCT_WRITEIOPS);
1198 #endif
1199 
1200 	r_old = racct->r_resources[RACCT_PCTCPU];
1201 
1202 	/* If there is nothing to decay, just exit. */
1203 	if (r_old <= 0)
1204 		return;
1205 
1206 	r_new = r_old * RACCT_DECAY_FACTOR / FSCALE;
1207 	racct->r_resources[RACCT_PCTCPU] = r_new;
1208 }
1209 
1210 static void
1211 racct_decay_pre(void)
1212 {
1213 
1214 	RACCT_LOCK();
1215 }
1216 
1217 static void
1218 racct_decay_post(void)
1219 {
1220 
1221 	RACCT_UNLOCK();
1222 }
1223 
1224 static void
1225 racct_decay(void)
1226 {
1227 
1228 	ASSERT_RACCT_ENABLED();
1229 
1230 	ui_racct_foreach(racct_decay_callback, racct_decay_pre,
1231 	    racct_decay_post, NULL, NULL);
1232 	loginclass_racct_foreach(racct_decay_callback, racct_decay_pre,
1233 	    racct_decay_post, NULL, NULL);
1234 	prison_racct_foreach(racct_decay_callback, racct_decay_pre,
1235 	    racct_decay_post, NULL, NULL);
1236 }
1237 
1238 static void
1239 racctd(void)
1240 {
1241 	struct thread *td;
1242 	struct proc *p;
1243 	struct timeval wallclock;
1244 	uint64_t pct, pct_estimate, runtime;
1245 
1246 	ASSERT_RACCT_ENABLED();
1247 
1248 	for (;;) {
1249 		racct_decay();
1250 
1251 		sx_slock(&allproc_lock);
1252 
1253 		FOREACH_PROC_IN_SYSTEM(p) {
1254 			PROC_LOCK(p);
1255 			if (p->p_state != PRS_NORMAL) {
1256 				if (p->p_state == PRS_ZOMBIE)
1257 					racct_set(p, RACCT_PCTCPU, 0);
1258 				PROC_UNLOCK(p);
1259 				continue;
1260 			}
1261 
1262 			microuptime(&wallclock);
1263 			timevalsub(&wallclock, &p->p_stats->p_start);
1264 			PROC_STATLOCK(p);
1265 			FOREACH_THREAD_IN_PROC(p, td)
1266 				ruxagg(p, td);
1267 			runtime = cputick2usec(p->p_rux.rux_runtime);
1268 			PROC_STATUNLOCK(p);
1269 #ifdef notyet
1270 			KASSERT(runtime >= p->p_prev_runtime,
1271 			    ("runtime < p_prev_runtime"));
1272 #else
1273 			if (runtime < p->p_prev_runtime)
1274 				runtime = p->p_prev_runtime;
1275 #endif
1276 			p->p_prev_runtime = runtime;
1277 			if (wallclock.tv_sec > 0 || wallclock.tv_usec > 0) {
1278 				pct_estimate = (1000000 * runtime * 100) /
1279 				    ((uint64_t)wallclock.tv_sec * 1000000 +
1280 				    wallclock.tv_usec);
1281 			} else
1282 				pct_estimate = 0;
1283 			pct = racct_getpcpu(p, pct_estimate);
1284 			RACCT_LOCK();
1285 #ifdef RCTL
1286 			rctl_throttle_decay(p->p_racct, RACCT_READBPS);
1287 			rctl_throttle_decay(p->p_racct, RACCT_WRITEBPS);
1288 			rctl_throttle_decay(p->p_racct, RACCT_READIOPS);
1289 			rctl_throttle_decay(p->p_racct, RACCT_WRITEIOPS);
1290 #endif
1291 			racct_set_locked(p, RACCT_PCTCPU, pct, 1);
1292 			racct_set_locked(p, RACCT_CPU, runtime, 0);
1293 			racct_set_locked(p, RACCT_WALLCLOCK,
1294 			    (uint64_t)wallclock.tv_sec * 1000000 +
1295 			    wallclock.tv_usec, 0);
1296 			RACCT_UNLOCK();
1297 			PROC_UNLOCK(p);
1298 		}
1299 
1300 		/*
1301 		 * To ensure that processes are throttled in a fair way, we need
1302 		 * to iterate over all processes again and check the limits
1303 		 * for %cpu resource only after ucred racct containers have been
1304 		 * properly filled.
1305 		 */
1306 		FOREACH_PROC_IN_SYSTEM(p) {
1307 			PROC_LOCK(p);
1308 			if (p->p_state != PRS_NORMAL) {
1309 				PROC_UNLOCK(p);
1310 				continue;
1311 			}
1312 
1313 			if (racct_pcpu_available(p) <= 0) {
1314 				if (p->p_racct->r_resources[RACCT_PCTCPU] >
1315 				    pcpu_threshold)
1316 					racct_proc_throttle(p, -1);
1317 			} else if (p->p_throttled == -1) {
1318 				racct_proc_wakeup(p);
1319 			}
1320 			PROC_UNLOCK(p);
1321 		}
1322 		sx_sunlock(&allproc_lock);
1323 		pause("-", hz);
1324 	}
1325 }
1326 
1327 static struct kproc_desc racctd_kp = {
1328 	"racctd",
1329 	racctd,
1330 	NULL
1331 };
1332 
1333 static void
1334 racctd_init(void)
1335 {
1336 	if (!racct_enable)
1337 		return;
1338 
1339 	kproc_start(&racctd_kp);
1340 }
1341 SYSINIT(racctd, SI_SUB_RACCTD, SI_ORDER_FIRST, racctd_init, NULL);
1342 
1343 static void
1344 racct_init(void)
1345 {
1346 	if (!racct_enable)
1347 		return;
1348 
1349 	racct_zone = uma_zcreate("racct", sizeof(struct racct),
1350 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1351 	ast_register(TDA_RACCT, ASTR_ASTF_REQUIRED, 0, ast_racct);
1352 
1353 	/*
1354 	 * XXX: Move this somewhere.
1355 	 */
1356 	prison0.pr_prison_racct = prison_racct_find("0");
1357 }
1358 SYSINIT(racct, SI_SUB_RACCT, SI_ORDER_FIRST, racct_init, NULL);
1359