xref: /freebsd/sys/kern/kern_racct.c (revision d6b92ffa)
1 /*-
2  * Copyright (c) 2010 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Edward Tomasz Napierala under sponsorship
6  * from the FreeBSD Foundation.
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, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_sched.h"
36 
37 #include <sys/param.h>
38 #include <sys/buf.h>
39 #include <sys/systm.h>
40 #include <sys/eventhandler.h>
41 #include <sys/jail.h>
42 #include <sys/kernel.h>
43 #include <sys/kthread.h>
44 #include <sys/lock.h>
45 #include <sys/loginclass.h>
46 #include <sys/malloc.h>
47 #include <sys/mutex.h>
48 #include <sys/proc.h>
49 #include <sys/racct.h>
50 #include <sys/resourcevar.h>
51 #include <sys/sbuf.h>
52 #include <sys/sched.h>
53 #include <sys/sdt.h>
54 #include <sys/smp.h>
55 #include <sys/sx.h>
56 #include <sys/sysctl.h>
57 #include <sys/sysent.h>
58 #include <sys/sysproto.h>
59 #include <sys/umtx.h>
60 #include <machine/smp.h>
61 
62 #ifdef RCTL
63 #include <sys/rctl.h>
64 #endif
65 
66 #ifdef RACCT
67 
68 FEATURE(racct, "Resource Accounting");
69 
70 /*
71  * Do not block processes that have their %cpu usage <= pcpu_threshold.
72  */
73 static int pcpu_threshold = 1;
74 #ifdef RACCT_DEFAULT_TO_DISABLED
75 int racct_enable = 0;
76 #else
77 int racct_enable = 1;
78 #endif
79 
80 SYSCTL_NODE(_kern, OID_AUTO, racct, CTLFLAG_RW, 0, "Resource Accounting");
81 SYSCTL_UINT(_kern_racct, OID_AUTO, enable, CTLFLAG_RDTUN, &racct_enable,
82     0, "Enable RACCT/RCTL");
83 SYSCTL_UINT(_kern_racct, OID_AUTO, pcpu_threshold, CTLFLAG_RW, &pcpu_threshold,
84     0, "Processes with higher %cpu usage than this value can be throttled.");
85 
86 /*
87  * How many seconds it takes to use the scheduler %cpu calculations.  When a
88  * process starts, we compute its %cpu usage by dividing its runtime by the
89  * process wall clock time.  After RACCT_PCPU_SECS pass, we use the value
90  * provided by the scheduler.
91  */
92 #define RACCT_PCPU_SECS		3
93 
94 struct mtx racct_lock;
95 MTX_SYSINIT(racct_lock, &racct_lock, "racct lock", MTX_DEF);
96 
97 static uma_zone_t racct_zone;
98 
99 static void racct_sub_racct(struct racct *dest, const struct racct *src);
100 static void racct_sub_cred_locked(struct ucred *cred, int resource,
101 		uint64_t amount);
102 static void racct_add_cred_locked(struct ucred *cred, int resource,
103 		uint64_t amount);
104 
105 SDT_PROVIDER_DEFINE(racct);
106 SDT_PROBE_DEFINE3(racct, , rusage, add,
107     "struct proc *", "int", "uint64_t");
108 SDT_PROBE_DEFINE3(racct, , rusage, add__failure,
109     "struct proc *", "int", "uint64_t");
110 SDT_PROBE_DEFINE3(racct, , rusage, add__buf,
111     "struct proc *", "const struct buf *", "int");
112 SDT_PROBE_DEFINE3(racct, , rusage, add__cred,
113     "struct ucred *", "int", "uint64_t");
114 SDT_PROBE_DEFINE3(racct, , rusage, add__force,
115     "struct proc *", "int", "uint64_t");
116 SDT_PROBE_DEFINE3(racct, , rusage, set,
117     "struct proc *", "int", "uint64_t");
118 SDT_PROBE_DEFINE3(racct, , rusage, set__failure,
119     "struct proc *", "int", "uint64_t");
120 SDT_PROBE_DEFINE3(racct, , rusage, set__force,
121     "struct proc *", "int", "uint64_t");
122 SDT_PROBE_DEFINE3(racct, , rusage, sub,
123     "struct proc *", "int", "uint64_t");
124 SDT_PROBE_DEFINE3(racct, , rusage, sub__cred,
125     "struct ucred *", "int", "uint64_t");
126 SDT_PROBE_DEFINE1(racct, , racct, create,
127     "struct racct *");
128 SDT_PROBE_DEFINE1(racct, , racct, destroy,
129     "struct racct *");
130 SDT_PROBE_DEFINE2(racct, , racct, join,
131     "struct racct *", "struct racct *");
132 SDT_PROBE_DEFINE2(racct, , racct, join__failure,
133     "struct racct *", "struct racct *");
134 SDT_PROBE_DEFINE2(racct, , racct, leave,
135     "struct racct *", "struct racct *");
136 
137 int racct_types[] = {
138 	[RACCT_CPU] =
139 		RACCT_IN_MILLIONS,
140 	[RACCT_DATA] =
141 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
142 	[RACCT_STACK] =
143 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
144 	[RACCT_CORE] =
145 		RACCT_DENIABLE,
146 	[RACCT_RSS] =
147 		RACCT_RECLAIMABLE,
148 	[RACCT_MEMLOCK] =
149 		RACCT_RECLAIMABLE | RACCT_DENIABLE,
150 	[RACCT_NPROC] =
151 		RACCT_RECLAIMABLE | RACCT_DENIABLE,
152 	[RACCT_NOFILE] =
153 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
154 	[RACCT_VMEM] =
155 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
156 	[RACCT_NPTS] =
157 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
158 	[RACCT_SWAP] =
159 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
160 	[RACCT_NTHR] =
161 		RACCT_RECLAIMABLE | RACCT_DENIABLE,
162 	[RACCT_MSGQQUEUED] =
163 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
164 	[RACCT_MSGQSIZE] =
165 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
166 	[RACCT_NMSGQ] =
167 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
168 	[RACCT_NSEM] =
169 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
170 	[RACCT_NSEMOP] =
171 		RACCT_RECLAIMABLE | RACCT_INHERITABLE | RACCT_DENIABLE,
172 	[RACCT_NSHM] =
173 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
174 	[RACCT_SHMSIZE] =
175 		RACCT_RECLAIMABLE | RACCT_DENIABLE | RACCT_SLOPPY,
176 	[RACCT_WALLCLOCK] =
177 		RACCT_IN_MILLIONS,
178 	[RACCT_PCTCPU] =
179 		RACCT_DECAYING | RACCT_DENIABLE | RACCT_IN_MILLIONS,
180 	[RACCT_READBPS] =
181 		RACCT_DECAYING,
182 	[RACCT_WRITEBPS] =
183 		RACCT_DECAYING,
184 	[RACCT_READIOPS] =
185 		RACCT_DECAYING,
186 	[RACCT_WRITEIOPS] =
187 		RACCT_DECAYING };
188 
189 static const fixpt_t RACCT_DECAY_FACTOR = 0.3 * FSCALE;
190 
191 #ifdef SCHED_4BSD
192 /*
193  * Contains intermediate values for %cpu calculations to avoid using floating
194  * point in the kernel.
195  * ccpu_exp[k] = FSCALE * (ccpu/FSCALE)^k = FSCALE * exp(-k/20)
196  * It is needed only for the 4BSD scheduler, because in ULE, the ccpu equals to
197  * zero so the calculations are more straightforward.
198  */
199 fixpt_t ccpu_exp[] = {
200 	[0] = FSCALE * 1,
201 	[1] = FSCALE * 0.95122942450071400909,
202 	[2] = FSCALE * 0.90483741803595957316,
203 	[3] = FSCALE * 0.86070797642505780722,
204 	[4] = FSCALE * 0.81873075307798185866,
205 	[5] = FSCALE * 0.77880078307140486824,
206 	[6] = FSCALE * 0.74081822068171786606,
207 	[7] = FSCALE * 0.70468808971871343435,
208 	[8] = FSCALE * 0.67032004603563930074,
209 	[9] = FSCALE * 0.63762815162177329314,
210 	[10] = FSCALE * 0.60653065971263342360,
211 	[11] = FSCALE * 0.57694981038048669531,
212 	[12] = FSCALE * 0.54881163609402643262,
213 	[13] = FSCALE * 0.52204577676101604789,
214 	[14] = FSCALE * 0.49658530379140951470,
215 	[15] = FSCALE * 0.47236655274101470713,
216 	[16] = FSCALE * 0.44932896411722159143,
217 	[17] = FSCALE * 0.42741493194872666992,
218 	[18] = FSCALE * 0.40656965974059911188,
219 	[19] = FSCALE * 0.38674102345450120691,
220 	[20] = FSCALE * 0.36787944117144232159,
221 	[21] = FSCALE * 0.34993774911115535467,
222 	[22] = FSCALE * 0.33287108369807955328,
223 	[23] = FSCALE * 0.31663676937905321821,
224 	[24] = FSCALE * 0.30119421191220209664,
225 	[25] = FSCALE * 0.28650479686019010032,
226 	[26] = FSCALE * 0.27253179303401260312,
227 	[27] = FSCALE * 0.25924026064589150757,
228 	[28] = FSCALE * 0.24659696394160647693,
229 	[29] = FSCALE * 0.23457028809379765313,
230 	[30] = FSCALE * 0.22313016014842982893,
231 	[31] = FSCALE * 0.21224797382674305771,
232 	[32] = FSCALE * 0.20189651799465540848,
233 	[33] = FSCALE * 0.19204990862075411423,
234 	[34] = FSCALE * 0.18268352405273465022,
235 	[35] = FSCALE * 0.17377394345044512668,
236 	[36] = FSCALE * 0.16529888822158653829,
237 	[37] = FSCALE * 0.15723716631362761621,
238 	[38] = FSCALE * 0.14956861922263505264,
239 	[39] = FSCALE * 0.14227407158651357185,
240 	[40] = FSCALE * 0.13533528323661269189,
241 	[41] = FSCALE * 0.12873490358780421886,
242 	[42] = FSCALE * 0.12245642825298191021,
243 	[43] = FSCALE * 0.11648415777349695786,
244 	[44] = FSCALE * 0.11080315836233388333,
245 	[45] = FSCALE * 0.10539922456186433678,
246 	[46] = FSCALE * 0.10025884372280373372,
247 	[47] = FSCALE * 0.09536916221554961888,
248 	[48] = FSCALE * 0.09071795328941250337,
249 	[49] = FSCALE * 0.08629358649937051097,
250 	[50] = FSCALE * 0.08208499862389879516,
251 	[51] = FSCALE * 0.07808166600115315231,
252 	[52] = FSCALE * 0.07427357821433388042,
253 	[53] = FSCALE * 0.07065121306042958674,
254 	[54] = FSCALE * 0.06720551273974976512,
255 	[55] = FSCALE * 0.06392786120670757270,
256 	[56] = FSCALE * 0.06081006262521796499,
257 	[57] = FSCALE * 0.05784432087483846296,
258 	[58] = FSCALE * 0.05502322005640722902,
259 	[59] = FSCALE * 0.05233970594843239308,
260 	[60] = FSCALE * 0.04978706836786394297,
261 	[61] = FSCALE * 0.04735892439114092119,
262 	[62] = FSCALE * 0.04504920239355780606,
263 	[63] = FSCALE * 0.04285212686704017991,
264 	[64] = FSCALE * 0.04076220397836621516,
265 	[65] = FSCALE * 0.03877420783172200988,
266 	[66] = FSCALE * 0.03688316740124000544,
267 	[67] = FSCALE * 0.03508435410084502588,
268 	[68] = FSCALE * 0.03337326996032607948,
269 	[69] = FSCALE * 0.03174563637806794323,
270 	[70] = FSCALE * 0.03019738342231850073,
271 	[71] = FSCALE * 0.02872463965423942912,
272 	[72] = FSCALE * 0.02732372244729256080,
273 	[73] = FSCALE * 0.02599112877875534358,
274 	[74] = FSCALE * 0.02472352647033939120,
275 	[75] = FSCALE * 0.02351774585600910823,
276 	[76] = FSCALE * 0.02237077185616559577,
277 	[77] = FSCALE * 0.02127973643837716938,
278 	[78] = FSCALE * 0.02024191144580438847,
279 	[79] = FSCALE * 0.01925470177538692429,
280 	[80] = FSCALE * 0.01831563888873418029,
281 	[81] = FSCALE * 0.01742237463949351138,
282 	[82] = FSCALE * 0.01657267540176124754,
283 	[83] = FSCALE * 0.01576441648485449082,
284 	[84] = FSCALE * 0.01499557682047770621,
285 	[85] = FSCALE * 0.01426423390899925527,
286 	[86] = FSCALE * 0.01356855901220093175,
287 	[87] = FSCALE * 0.01290681258047986886,
288 	[88] = FSCALE * 0.01227733990306844117,
289 	[89] = FSCALE * 0.01167856697039544521,
290 	[90] = FSCALE * 0.01110899653824230649,
291 	[91] = FSCALE * 0.01056720438385265337,
292 	[92] = FSCALE * 0.01005183574463358164,
293 	[93] = FSCALE * 0.00956160193054350793,
294 	[94] = FSCALE * 0.00909527710169581709,
295 	[95] = FSCALE * 0.00865169520312063417,
296 	[96] = FSCALE * 0.00822974704902002884,
297 	[97] = FSCALE * 0.00782837754922577143,
298 	[98] = FSCALE * 0.00744658307092434051,
299 	[99] = FSCALE * 0.00708340892905212004,
300 	[100] = FSCALE * 0.00673794699908546709,
301 	[101] = FSCALE * 0.00640933344625638184,
302 	[102] = FSCALE * 0.00609674656551563610,
303 	[103] = FSCALE * 0.00579940472684214321,
304 	[104] = FSCALE * 0.00551656442076077241,
305 	[105] = FSCALE * 0.00524751839918138427,
306 	[106] = FSCALE * 0.00499159390691021621,
307 	[107] = FSCALE * 0.00474815099941147558,
308 	[108] = FSCALE * 0.00451658094261266798,
309 	[109] = FSCALE * 0.00429630469075234057,
310 	[110] = FSCALE * 0.00408677143846406699,
311 };
312 #endif
313 
314 #define	CCPU_EXP_MAX	110
315 
316 /*
317  * This function is analogical to the getpcpu() function in the ps(1) command.
318  * They should both calculate in the same way so that the racct %cpu
319  * calculations are consistent with the values showed by the ps(1) tool.
320  * The calculations are more complex in the 4BSD scheduler because of the value
321  * of the ccpu variable.  In ULE it is defined to be zero which saves us some
322  * work.
323  */
324 static uint64_t
325 racct_getpcpu(struct proc *p, u_int pcpu)
326 {
327 	u_int swtime;
328 #ifdef SCHED_4BSD
329 	fixpt_t pctcpu, pctcpu_next;
330 #endif
331 #ifdef SMP
332 	struct pcpu *pc;
333 	int found;
334 #endif
335 	fixpt_t p_pctcpu;
336 	struct thread *td;
337 
338 	ASSERT_RACCT_ENABLED();
339 
340 	/*
341 	 * If the process is swapped out, we count its %cpu usage as zero.
342 	 * This behaviour is consistent with the userland ps(1) tool.
343 	 */
344 	if ((p->p_flag & P_INMEM) == 0)
345 		return (0);
346 	swtime = (ticks - p->p_swtick) / hz;
347 
348 	/*
349 	 * For short-lived processes, the sched_pctcpu() returns small
350 	 * values even for cpu intensive processes.  Therefore we use
351 	 * our own estimate in this case.
352 	 */
353 	if (swtime < RACCT_PCPU_SECS)
354 		return (pcpu);
355 
356 	p_pctcpu = 0;
357 	FOREACH_THREAD_IN_PROC(p, td) {
358 		if (td == PCPU_GET(idlethread))
359 			continue;
360 #ifdef SMP
361 		found = 0;
362 		STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
363 			if (td == pc->pc_idlethread) {
364 				found = 1;
365 				break;
366 			}
367 		}
368 		if (found)
369 			continue;
370 #endif
371 		thread_lock(td);
372 #ifdef SCHED_4BSD
373 		pctcpu = sched_pctcpu(td);
374 		/* Count also the yet unfinished second. */
375 		pctcpu_next = (pctcpu * ccpu_exp[1]) >> FSHIFT;
376 		pctcpu_next += sched_pctcpu_delta(td);
377 		p_pctcpu += max(pctcpu, pctcpu_next);
378 #else
379 		/*
380 		 * In ULE the %cpu statistics are updated on every
381 		 * sched_pctcpu() call.  So special calculations to
382 		 * account for the latest (unfinished) second are
383 		 * not needed.
384 		 */
385 		p_pctcpu += sched_pctcpu(td);
386 #endif
387 		thread_unlock(td);
388 	}
389 
390 #ifdef SCHED_4BSD
391 	if (swtime <= CCPU_EXP_MAX)
392 		return ((100 * (uint64_t)p_pctcpu * 1000000) /
393 		    (FSCALE - ccpu_exp[swtime]));
394 #endif
395 
396 	return ((100 * (uint64_t)p_pctcpu * 1000000) / FSCALE);
397 }
398 
399 static void
400 racct_add_racct(struct racct *dest, const struct racct *src)
401 {
402 	int i;
403 
404 	ASSERT_RACCT_ENABLED();
405 	RACCT_LOCK_ASSERT();
406 
407 	/*
408 	 * Update resource usage in dest.
409 	 */
410 	for (i = 0; i <= RACCT_MAX; i++) {
411 		KASSERT(dest->r_resources[i] >= 0,
412 		    ("%s: resource %d propagation meltdown: dest < 0",
413 		    __func__, i));
414 		KASSERT(src->r_resources[i] >= 0,
415 		    ("%s: resource %d propagation meltdown: src < 0",
416 		    __func__, i));
417 		dest->r_resources[i] += src->r_resources[i];
418 	}
419 }
420 
421 static void
422 racct_sub_racct(struct racct *dest, const struct racct *src)
423 {
424 	int i;
425 
426 	ASSERT_RACCT_ENABLED();
427 	RACCT_LOCK_ASSERT();
428 
429 	/*
430 	 * Update resource usage in dest.
431 	 */
432 	for (i = 0; i <= RACCT_MAX; i++) {
433 		if (!RACCT_IS_SLOPPY(i) && !RACCT_IS_DECAYING(i)) {
434 			KASSERT(dest->r_resources[i] >= 0,
435 			    ("%s: resource %d propagation meltdown: dest < 0",
436 			    __func__, i));
437 			KASSERT(src->r_resources[i] >= 0,
438 			    ("%s: resource %d propagation meltdown: src < 0",
439 			    __func__, i));
440 			KASSERT(src->r_resources[i] <= dest->r_resources[i],
441 			    ("%s: resource %d propagation meltdown: src > dest",
442 			    __func__, i));
443 		}
444 		if (RACCT_CAN_DROP(i)) {
445 			dest->r_resources[i] -= src->r_resources[i];
446 			if (dest->r_resources[i] < 0)
447 				dest->r_resources[i] = 0;
448 		}
449 	}
450 }
451 
452 void
453 racct_create(struct racct **racctp)
454 {
455 
456 	if (!racct_enable)
457 		return;
458 
459 	SDT_PROBE1(racct, , racct, create, racctp);
460 
461 	KASSERT(*racctp == NULL, ("racct already allocated"));
462 
463 	*racctp = uma_zalloc(racct_zone, M_WAITOK | M_ZERO);
464 }
465 
466 static void
467 racct_destroy_locked(struct racct **racctp)
468 {
469 	struct racct *racct;
470 	int i;
471 
472 	ASSERT_RACCT_ENABLED();
473 
474 	SDT_PROBE1(racct, , racct, destroy, racctp);
475 
476 	RACCT_LOCK_ASSERT();
477 	KASSERT(racctp != NULL, ("NULL racctp"));
478 	KASSERT(*racctp != NULL, ("NULL racct"));
479 
480 	racct = *racctp;
481 
482 	for (i = 0; i <= RACCT_MAX; i++) {
483 		if (RACCT_IS_SLOPPY(i))
484 			continue;
485 		if (!RACCT_IS_RECLAIMABLE(i))
486 			continue;
487 		KASSERT(racct->r_resources[i] == 0,
488 		    ("destroying non-empty racct: "
489 		    "%ju allocated for resource %d\n",
490 		    racct->r_resources[i], i));
491 	}
492 	uma_zfree(racct_zone, racct);
493 	*racctp = NULL;
494 }
495 
496 void
497 racct_destroy(struct racct **racct)
498 {
499 
500 	if (!racct_enable)
501 		return;
502 
503 	RACCT_LOCK();
504 	racct_destroy_locked(racct);
505 	RACCT_UNLOCK();
506 }
507 
508 /*
509  * Increase consumption of 'resource' by 'amount' for 'racct',
510  * but not its parents.  Differently from other cases, 'amount' here
511  * may be less than zero.
512  */
513 static void
514 racct_adjust_resource(struct racct *racct, int resource,
515     int64_t amount)
516 {
517 
518 	ASSERT_RACCT_ENABLED();
519 	RACCT_LOCK_ASSERT();
520 	KASSERT(racct != NULL, ("NULL racct"));
521 
522 	racct->r_resources[resource] += amount;
523 	if (racct->r_resources[resource] < 0) {
524 		KASSERT(RACCT_IS_SLOPPY(resource) || RACCT_IS_DECAYING(resource),
525 		    ("%s: resource %d usage < 0", __func__, resource));
526 		racct->r_resources[resource] = 0;
527 	}
528 
529 	/*
530 	 * There are some cases where the racct %cpu resource would grow
531 	 * beyond 100% per core.  For example in racct_proc_exit() we add
532 	 * the process %cpu usage to the ucred racct containers.  If too
533 	 * many processes terminated in a short time span, the ucred %cpu
534 	 * resource could grow too much.  Also, the 4BSD scheduler sometimes
535 	 * returns for a thread more than 100% cpu usage. So we set a sane
536 	 * boundary here to 100% * the maxumum number of CPUs.
537 	 */
538 	if ((resource == RACCT_PCTCPU) &&
539 	    (racct->r_resources[RACCT_PCTCPU] > 100 * 1000000 * (int64_t)MAXCPU))
540 		racct->r_resources[RACCT_PCTCPU] = 100 * 1000000 * (int64_t)MAXCPU;
541 }
542 
543 static int
544 racct_add_locked(struct proc *p, int resource, uint64_t amount, int force)
545 {
546 #ifdef RCTL
547 	int error;
548 #endif
549 
550 	ASSERT_RACCT_ENABLED();
551 
552 	/*
553 	 * We need proc lock to dereference p->p_ucred.
554 	 */
555 	PROC_LOCK_ASSERT(p, MA_OWNED);
556 
557 #ifdef RCTL
558 	error = rctl_enforce(p, resource, amount);
559 	if (error && !force && RACCT_IS_DENIABLE(resource)) {
560 		SDT_PROBE3(racct, , rusage, add__failure, p, resource, amount);
561 		return (error);
562 	}
563 #endif
564 	racct_adjust_resource(p->p_racct, resource, amount);
565 	racct_add_cred_locked(p->p_ucred, resource, amount);
566 
567 	return (0);
568 }
569 
570 /*
571  * Increase allocation of 'resource' by 'amount' for process 'p'.
572  * Return 0 if it's below limits, or errno, if it's not.
573  */
574 int
575 racct_add(struct proc *p, int resource, uint64_t amount)
576 {
577 	int error;
578 
579 	if (!racct_enable)
580 		return (0);
581 
582 	SDT_PROBE3(racct, , rusage, add, p, resource, amount);
583 
584 	RACCT_LOCK();
585 	error = racct_add_locked(p, resource, amount, 0);
586 	RACCT_UNLOCK();
587 	return (error);
588 }
589 
590 /*
591  * Increase allocation of 'resource' by 'amount' for process 'p'.
592  * Doesn't check for limits and never fails.
593  */
594 void
595 racct_add_force(struct proc *p, int resource, uint64_t amount)
596 {
597 
598 	if (!racct_enable)
599 		return;
600 
601 	SDT_PROBE3(racct, , rusage, add__force, p, resource, amount);
602 
603 	RACCT_LOCK();
604 	racct_add_locked(p, resource, amount, 1);
605 	RACCT_UNLOCK();
606 }
607 
608 static void
609 racct_add_cred_locked(struct ucred *cred, int resource, uint64_t amount)
610 {
611 	struct prison *pr;
612 
613 	ASSERT_RACCT_ENABLED();
614 
615 	racct_adjust_resource(cred->cr_ruidinfo->ui_racct, resource, amount);
616 	for (pr = cred->cr_prison; pr != NULL; pr = pr->pr_parent)
617 		racct_adjust_resource(pr->pr_prison_racct->prr_racct, resource,
618 		    amount);
619 	racct_adjust_resource(cred->cr_loginclass->lc_racct, resource, amount);
620 }
621 
622 /*
623  * Increase allocation of 'resource' by 'amount' for credential 'cred'.
624  * Doesn't check for limits and never fails.
625  */
626 void
627 racct_add_cred(struct ucred *cred, int resource, uint64_t amount)
628 {
629 
630 	if (!racct_enable)
631 		return;
632 
633 	SDT_PROBE3(racct, , rusage, add__cred, cred, resource, amount);
634 
635 	RACCT_LOCK();
636 	racct_add_cred_locked(cred, resource, amount);
637 	RACCT_UNLOCK();
638 }
639 
640 /*
641  * Account for disk IO resource consumption.  Checks for limits,
642  * but never fails, due to disk limits being undeniable.
643  */
644 void
645 racct_add_buf(struct proc *p, const struct buf *bp, int is_write)
646 {
647 
648 	ASSERT_RACCT_ENABLED();
649 	PROC_LOCK_ASSERT(p, MA_OWNED);
650 
651 	SDT_PROBE3(racct, , rusage, add__buf, p, bp, is_write);
652 
653 	RACCT_LOCK();
654 	if (is_write) {
655 		racct_add_locked(curproc, RACCT_WRITEBPS, bp->b_bcount, 1);
656 		racct_add_locked(curproc, RACCT_WRITEIOPS, 1, 1);
657 	} else {
658 		racct_add_locked(curproc, RACCT_READBPS, bp->b_bcount, 1);
659 		racct_add_locked(curproc, RACCT_READIOPS, 1, 1);
660 	}
661 	RACCT_UNLOCK();
662 }
663 
664 static int
665 racct_set_locked(struct proc *p, int resource, uint64_t amount, int force)
666 {
667 	int64_t old_amount, decayed_amount, diff_proc, diff_cred;
668 #ifdef RCTL
669 	int error;
670 #endif
671 
672 	ASSERT_RACCT_ENABLED();
673 
674 	/*
675 	 * We need proc lock to dereference p->p_ucred.
676 	 */
677 	PROC_LOCK_ASSERT(p, MA_OWNED);
678 
679 	old_amount = p->p_racct->r_resources[resource];
680 	/*
681 	 * The diffs may be negative.
682 	 */
683 	diff_proc = amount - old_amount;
684 	if (resource == RACCT_PCTCPU) {
685 		/*
686 		 * Resources in per-credential racct containers may decay.
687 		 * If this is the case, we need to calculate the difference
688 		 * between the new amount and the proportional value of the
689 		 * old amount that has decayed in the ucred racct containers.
690 		 */
691 		decayed_amount = old_amount * RACCT_DECAY_FACTOR / FSCALE;
692 		diff_cred = amount - decayed_amount;
693 	} else
694 		diff_cred = diff_proc;
695 #ifdef notyet
696 	KASSERT(diff_proc >= 0 || RACCT_CAN_DROP(resource),
697 	    ("%s: usage of non-droppable resource %d dropping", __func__,
698 	     resource));
699 #endif
700 #ifdef RCTL
701 	if (diff_proc > 0) {
702 		error = rctl_enforce(p, resource, diff_proc);
703 		if (error && !force && RACCT_IS_DENIABLE(resource)) {
704 			SDT_PROBE3(racct, , rusage, set__failure, p, resource,
705 			    amount);
706 			return (error);
707 		}
708 	}
709 #endif
710 	racct_adjust_resource(p->p_racct, resource, diff_proc);
711 	if (diff_cred > 0)
712 		racct_add_cred_locked(p->p_ucred, resource, diff_cred);
713 	else if (diff_cred < 0)
714 		racct_sub_cred_locked(p->p_ucred, resource, -diff_cred);
715 
716 	return (0);
717 }
718 
719 /*
720  * Set allocation of 'resource' to 'amount' for process 'p'.
721  * Return 0 if it's below limits, or errno, if it's not.
722  *
723  * Note that decreasing the allocation always returns 0,
724  * even if it's above the limit.
725  */
726 int
727 racct_set(struct proc *p, int resource, uint64_t amount)
728 {
729 	int error;
730 
731 	if (!racct_enable)
732 		return (0);
733 
734 	SDT_PROBE3(racct, , rusage, set__force, p, resource, amount);
735 
736 	RACCT_LOCK();
737 	error = racct_set_locked(p, resource, amount, 0);
738 	RACCT_UNLOCK();
739 	return (error);
740 }
741 
742 void
743 racct_set_force(struct proc *p, int resource, uint64_t amount)
744 {
745 
746 	if (!racct_enable)
747 		return;
748 
749 	SDT_PROBE3(racct, , rusage, set, p, resource, amount);
750 
751 	RACCT_LOCK();
752 	racct_set_locked(p, resource, amount, 1);
753 	RACCT_UNLOCK();
754 }
755 
756 /*
757  * Returns amount of 'resource' the process 'p' can keep allocated.
758  * Allocating more than that would be denied, unless the resource
759  * is marked undeniable.  Amount of already allocated resource does
760  * not matter.
761  */
762 uint64_t
763 racct_get_limit(struct proc *p, int resource)
764 {
765 #ifdef RCTL
766 	uint64_t available;
767 
768 	if (!racct_enable)
769 		return (UINT64_MAX);
770 
771 	RACCT_LOCK();
772 	available = rctl_get_limit(p, resource);
773 	RACCT_UNLOCK();
774 
775 	return (available);
776 #else
777 
778 	return (UINT64_MAX);
779 #endif
780 }
781 
782 /*
783  * Returns amount of 'resource' the process 'p' can keep allocated.
784  * Allocating more than that would be denied, unless the resource
785  * is marked undeniable.  Amount of already allocated resource does
786  * matter.
787  */
788 uint64_t
789 racct_get_available(struct proc *p, int resource)
790 {
791 #ifdef RCTL
792 	uint64_t available;
793 
794 	if (!racct_enable)
795 		return (UINT64_MAX);
796 
797 	RACCT_LOCK();
798 	available = rctl_get_available(p, resource);
799 	RACCT_UNLOCK();
800 
801 	return (available);
802 #else
803 
804 	return (UINT64_MAX);
805 #endif
806 }
807 
808 /*
809  * Returns amount of the %cpu resource that process 'p' can add to its %cpu
810  * utilization.  Adding more than that would lead to the process being
811  * throttled.
812  */
813 static int64_t
814 racct_pcpu_available(struct proc *p)
815 {
816 #ifdef RCTL
817 	uint64_t available;
818 
819 	ASSERT_RACCT_ENABLED();
820 
821 	RACCT_LOCK();
822 	available = rctl_pcpu_available(p);
823 	RACCT_UNLOCK();
824 
825 	return (available);
826 #else
827 
828 	return (INT64_MAX);
829 #endif
830 }
831 
832 /*
833  * Decrease allocation of 'resource' by 'amount' for process 'p'.
834  */
835 void
836 racct_sub(struct proc *p, int resource, uint64_t amount)
837 {
838 
839 	if (!racct_enable)
840 		return;
841 
842 	SDT_PROBE3(racct, , rusage, sub, p, resource, amount);
843 
844 	/*
845 	 * We need proc lock to dereference p->p_ucred.
846 	 */
847 	PROC_LOCK_ASSERT(p, MA_OWNED);
848 	KASSERT(RACCT_CAN_DROP(resource),
849 	    ("%s: called for non-droppable resource %d", __func__, resource));
850 
851 	RACCT_LOCK();
852 	KASSERT(amount <= p->p_racct->r_resources[resource],
853 	    ("%s: freeing %ju of resource %d, which is more "
854 	     "than allocated %jd for %s (pid %d)", __func__, amount, resource,
855 	    (intmax_t)p->p_racct->r_resources[resource], p->p_comm, p->p_pid));
856 
857 	racct_adjust_resource(p->p_racct, resource, -amount);
858 	racct_sub_cred_locked(p->p_ucred, resource, amount);
859 	RACCT_UNLOCK();
860 }
861 
862 static void
863 racct_sub_cred_locked(struct ucred *cred, int resource, uint64_t amount)
864 {
865 	struct prison *pr;
866 
867 	ASSERT_RACCT_ENABLED();
868 
869 	racct_adjust_resource(cred->cr_ruidinfo->ui_racct, resource, -amount);
870 	for (pr = cred->cr_prison; pr != NULL; pr = pr->pr_parent)
871 		racct_adjust_resource(pr->pr_prison_racct->prr_racct, resource,
872 		    -amount);
873 	racct_adjust_resource(cred->cr_loginclass->lc_racct, resource, -amount);
874 }
875 
876 /*
877  * Decrease allocation of 'resource' by 'amount' for credential 'cred'.
878  */
879 void
880 racct_sub_cred(struct ucred *cred, int resource, uint64_t amount)
881 {
882 
883 	if (!racct_enable)
884 		return;
885 
886 	SDT_PROBE3(racct, , rusage, sub__cred, cred, resource, amount);
887 
888 #ifdef notyet
889 	KASSERT(RACCT_CAN_DROP(resource),
890 	    ("%s: called for resource %d which can not drop", __func__,
891 	     resource));
892 #endif
893 
894 	RACCT_LOCK();
895 	racct_sub_cred_locked(cred, resource, amount);
896 	RACCT_UNLOCK();
897 }
898 
899 /*
900  * Inherit resource usage information from the parent process.
901  */
902 int
903 racct_proc_fork(struct proc *parent, struct proc *child)
904 {
905 	int i, error = 0;
906 
907 	if (!racct_enable)
908 		return (0);
909 
910 	/*
911 	 * Create racct for the child process.
912 	 */
913 	racct_create(&child->p_racct);
914 
915 	PROC_LOCK(parent);
916 	PROC_LOCK(child);
917 	RACCT_LOCK();
918 
919 #ifdef RCTL
920 	error = rctl_proc_fork(parent, child);
921 	if (error != 0)
922 		goto out;
923 #endif
924 
925 	/* Init process cpu time. */
926 	child->p_prev_runtime = 0;
927 	child->p_throttled = 0;
928 
929 	/*
930 	 * Inherit resource usage.
931 	 */
932 	for (i = 0; i <= RACCT_MAX; i++) {
933 		if (parent->p_racct->r_resources[i] == 0 ||
934 		    !RACCT_IS_INHERITABLE(i))
935 			continue;
936 
937 		error = racct_set_locked(child, i,
938 		    parent->p_racct->r_resources[i], 0);
939 		if (error != 0)
940 			goto out;
941 	}
942 
943 	error = racct_add_locked(child, RACCT_NPROC, 1, 0);
944 	error += racct_add_locked(child, RACCT_NTHR, 1, 0);
945 
946 out:
947 	RACCT_UNLOCK();
948 	PROC_UNLOCK(child);
949 	PROC_UNLOCK(parent);
950 
951 	if (error != 0)
952 		racct_proc_exit(child);
953 
954 	return (error);
955 }
956 
957 /*
958  * Called at the end of fork1(), to handle rules that require the process
959  * to be fully initialized.
960  */
961 void
962 racct_proc_fork_done(struct proc *child)
963 {
964 
965 	if (!racct_enable)
966 		return;
967 
968 	PROC_LOCK_ASSERT(child, MA_OWNED);
969 
970 #ifdef RCTL
971 	RACCT_LOCK();
972 	rctl_enforce(child, RACCT_NPROC, 0);
973 	rctl_enforce(child, RACCT_NTHR, 0);
974 	RACCT_UNLOCK();
975 #endif
976 }
977 
978 void
979 racct_proc_exit(struct proc *p)
980 {
981 	struct timeval wallclock;
982 	uint64_t pct_estimate, pct, runtime;
983 	int i;
984 
985 	if (!racct_enable)
986 		return;
987 
988 	PROC_LOCK(p);
989 	/*
990 	 * We don't need to calculate rux, proc_reap() has already done this.
991 	 */
992 	runtime = cputick2usec(p->p_rux.rux_runtime);
993 #ifdef notyet
994 	KASSERT(runtime >= p->p_prev_runtime, ("runtime < p_prev_runtime"));
995 #else
996 	if (runtime < p->p_prev_runtime)
997 		runtime = p->p_prev_runtime;
998 #endif
999 	microuptime(&wallclock);
1000 	timevalsub(&wallclock, &p->p_stats->p_start);
1001 	if (wallclock.tv_sec > 0 || wallclock.tv_usec > 0) {
1002 		pct_estimate = (1000000 * runtime * 100) /
1003 		    ((uint64_t)wallclock.tv_sec * 1000000 +
1004 		    wallclock.tv_usec);
1005 	} else
1006 		pct_estimate = 0;
1007 	pct = racct_getpcpu(p, pct_estimate);
1008 
1009 	RACCT_LOCK();
1010 	racct_set_locked(p, RACCT_CPU, runtime, 0);
1011 	racct_add_cred_locked(p->p_ucred, RACCT_PCTCPU, pct);
1012 
1013 	KASSERT(p->p_racct->r_resources[RACCT_RSS] == 0,
1014 	    ("process reaped with %ju allocated for RSS\n",
1015 	    p->p_racct->r_resources[RACCT_RSS]));
1016 	for (i = 0; i <= RACCT_MAX; i++) {
1017 		if (p->p_racct->r_resources[i] == 0)
1018 			continue;
1019 		if (!RACCT_IS_RECLAIMABLE(i))
1020 			continue;
1021 		racct_set_locked(p, i, 0, 0);
1022 	}
1023 
1024 #ifdef RCTL
1025 	rctl_racct_release(p->p_racct);
1026 #endif
1027 	racct_destroy_locked(&p->p_racct);
1028 	RACCT_UNLOCK();
1029 	PROC_UNLOCK(p);
1030 }
1031 
1032 /*
1033  * Called after credentials change, to move resource utilisation
1034  * between raccts.
1035  */
1036 void
1037 racct_proc_ucred_changed(struct proc *p, struct ucred *oldcred,
1038     struct ucred *newcred)
1039 {
1040 	struct uidinfo *olduip, *newuip;
1041 	struct loginclass *oldlc, *newlc;
1042 	struct prison *oldpr, *newpr, *pr;
1043 
1044 	if (!racct_enable)
1045 		return;
1046 
1047 	PROC_LOCK_ASSERT(p, MA_NOTOWNED);
1048 
1049 	newuip = newcred->cr_ruidinfo;
1050 	olduip = oldcred->cr_ruidinfo;
1051 	newlc = newcred->cr_loginclass;
1052 	oldlc = oldcred->cr_loginclass;
1053 	newpr = newcred->cr_prison;
1054 	oldpr = oldcred->cr_prison;
1055 
1056 	RACCT_LOCK();
1057 	if (newuip != olduip) {
1058 		racct_sub_racct(olduip->ui_racct, p->p_racct);
1059 		racct_add_racct(newuip->ui_racct, p->p_racct);
1060 	}
1061 	if (newlc != oldlc) {
1062 		racct_sub_racct(oldlc->lc_racct, p->p_racct);
1063 		racct_add_racct(newlc->lc_racct, p->p_racct);
1064 	}
1065 	if (newpr != oldpr) {
1066 		for (pr = oldpr; pr != NULL; pr = pr->pr_parent)
1067 			racct_sub_racct(pr->pr_prison_racct->prr_racct,
1068 			    p->p_racct);
1069 		for (pr = newpr; pr != NULL; pr = pr->pr_parent)
1070 			racct_add_racct(pr->pr_prison_racct->prr_racct,
1071 			    p->p_racct);
1072 	}
1073 	RACCT_UNLOCK();
1074 
1075 #ifdef RCTL
1076 	rctl_proc_ucred_changed(p, newcred);
1077 #endif
1078 }
1079 
1080 void
1081 racct_move(struct racct *dest, struct racct *src)
1082 {
1083 
1084 	ASSERT_RACCT_ENABLED();
1085 
1086 	RACCT_LOCK();
1087 	racct_add_racct(dest, src);
1088 	racct_sub_racct(src, src);
1089 	RACCT_UNLOCK();
1090 }
1091 
1092 /*
1093  * Make the process sleep in userret() for 'timeout' ticks.  Setting
1094  * timeout to -1 makes it sleep until woken up by racct_proc_wakeup().
1095  */
1096 void
1097 racct_proc_throttle(struct proc *p, int timeout)
1098 {
1099 	struct thread *td;
1100 #ifdef SMP
1101 	int cpuid;
1102 #endif
1103 
1104 	KASSERT(timeout != 0, ("timeout %d", timeout));
1105 	ASSERT_RACCT_ENABLED();
1106 	PROC_LOCK_ASSERT(p, MA_OWNED);
1107 
1108 	/*
1109 	 * Do not block kernel processes.  Also do not block processes with
1110 	 * low %cpu utilization to improve interactivity.
1111 	 */
1112 	if ((p->p_flag & (P_SYSTEM | P_KPROC)) != 0)
1113 		return;
1114 
1115 	if (p->p_throttled < 0 || (timeout > 0 && p->p_throttled > timeout))
1116 		return;
1117 
1118 	p->p_throttled = timeout;
1119 
1120 	FOREACH_THREAD_IN_PROC(p, td) {
1121 		thread_lock(td);
1122 		switch (td->td_state) {
1123 		case TDS_RUNQ:
1124 			/*
1125 			 * If the thread is on the scheduler run-queue, we can
1126 			 * not just remove it from there.  So we set the flag
1127 			 * TDF_NEEDRESCHED for the thread, so that once it is
1128 			 * running, it is taken off the cpu as soon as possible.
1129 			 */
1130 			td->td_flags |= TDF_NEEDRESCHED;
1131 			break;
1132 		case TDS_RUNNING:
1133 			/*
1134 			 * If the thread is running, we request a context
1135 			 * switch for it by setting the TDF_NEEDRESCHED flag.
1136 			 */
1137 			td->td_flags |= TDF_NEEDRESCHED;
1138 #ifdef SMP
1139 			cpuid = td->td_oncpu;
1140 			if ((cpuid != NOCPU) && (td != curthread))
1141 				ipi_cpu(cpuid, IPI_AST);
1142 #endif
1143 			break;
1144 		default:
1145 			break;
1146 		}
1147 		thread_unlock(td);
1148 	}
1149 }
1150 
1151 static void
1152 racct_proc_wakeup(struct proc *p)
1153 {
1154 
1155 	ASSERT_RACCT_ENABLED();
1156 
1157 	PROC_LOCK_ASSERT(p, MA_OWNED);
1158 
1159 	if (p->p_throttled != 0) {
1160 		p->p_throttled = 0;
1161 		wakeup(p->p_racct);
1162 	}
1163 }
1164 
1165 static void
1166 racct_decay_callback(struct racct *racct, void *dummy1, void *dummy2)
1167 {
1168 	int64_t r_old, r_new;
1169 
1170 	ASSERT_RACCT_ENABLED();
1171 	RACCT_LOCK_ASSERT();
1172 
1173 #ifdef RCTL
1174 	rctl_throttle_decay(racct, RACCT_READBPS);
1175 	rctl_throttle_decay(racct, RACCT_WRITEBPS);
1176 	rctl_throttle_decay(racct, RACCT_READIOPS);
1177 	rctl_throttle_decay(racct, RACCT_WRITEIOPS);
1178 #endif
1179 
1180 	r_old = racct->r_resources[RACCT_PCTCPU];
1181 
1182 	/* If there is nothing to decay, just exit. */
1183 	if (r_old <= 0)
1184 		return;
1185 
1186 	r_new = r_old * RACCT_DECAY_FACTOR / FSCALE;
1187 	racct->r_resources[RACCT_PCTCPU] = r_new;
1188 }
1189 
1190 static void
1191 racct_decay_pre(void)
1192 {
1193 
1194 	RACCT_LOCK();
1195 }
1196 
1197 static void
1198 racct_decay_post(void)
1199 {
1200 
1201 	RACCT_UNLOCK();
1202 }
1203 
1204 static void
1205 racct_decay(void)
1206 {
1207 
1208 	ASSERT_RACCT_ENABLED();
1209 
1210 	ui_racct_foreach(racct_decay_callback, racct_decay_pre,
1211 	    racct_decay_post, NULL, NULL);
1212 	loginclass_racct_foreach(racct_decay_callback, racct_decay_pre,
1213 	    racct_decay_post, NULL, NULL);
1214 	prison_racct_foreach(racct_decay_callback, racct_decay_pre,
1215 	    racct_decay_post, NULL, NULL);
1216 }
1217 
1218 static void
1219 racctd(void)
1220 {
1221 	struct thread *td;
1222 	struct proc *p;
1223 	struct timeval wallclock;
1224 	uint64_t pct, pct_estimate, runtime;
1225 
1226 	ASSERT_RACCT_ENABLED();
1227 
1228 	for (;;) {
1229 		racct_decay();
1230 
1231 		sx_slock(&allproc_lock);
1232 
1233 		LIST_FOREACH(p, &zombproc, p_list) {
1234 			PROC_LOCK(p);
1235 			racct_set(p, RACCT_PCTCPU, 0);
1236 			PROC_UNLOCK(p);
1237 		}
1238 
1239 		FOREACH_PROC_IN_SYSTEM(p) {
1240 			PROC_LOCK(p);
1241 			if (p->p_state != PRS_NORMAL) {
1242 				PROC_UNLOCK(p);
1243 				continue;
1244 			}
1245 
1246 			microuptime(&wallclock);
1247 			timevalsub(&wallclock, &p->p_stats->p_start);
1248 			PROC_STATLOCK(p);
1249 			FOREACH_THREAD_IN_PROC(p, td)
1250 				ruxagg(p, td);
1251 			runtime = cputick2usec(p->p_rux.rux_runtime);
1252 			PROC_STATUNLOCK(p);
1253 #ifdef notyet
1254 			KASSERT(runtime >= p->p_prev_runtime,
1255 			    ("runtime < p_prev_runtime"));
1256 #else
1257 			if (runtime < p->p_prev_runtime)
1258 				runtime = p->p_prev_runtime;
1259 #endif
1260 			p->p_prev_runtime = runtime;
1261 			if (wallclock.tv_sec > 0 || wallclock.tv_usec > 0) {
1262 				pct_estimate = (1000000 * runtime * 100) /
1263 				    ((uint64_t)wallclock.tv_sec * 1000000 +
1264 				    wallclock.tv_usec);
1265 			} else
1266 				pct_estimate = 0;
1267 			pct = racct_getpcpu(p, pct_estimate);
1268 			RACCT_LOCK();
1269 #ifdef RCTL
1270 			rctl_throttle_decay(p->p_racct, RACCT_READBPS);
1271 			rctl_throttle_decay(p->p_racct, RACCT_WRITEBPS);
1272 			rctl_throttle_decay(p->p_racct, RACCT_READIOPS);
1273 			rctl_throttle_decay(p->p_racct, RACCT_WRITEIOPS);
1274 #endif
1275 			racct_set_locked(p, RACCT_PCTCPU, pct, 1);
1276 			racct_set_locked(p, RACCT_CPU, runtime, 0);
1277 			racct_set_locked(p, RACCT_WALLCLOCK,
1278 			    (uint64_t)wallclock.tv_sec * 1000000 +
1279 			    wallclock.tv_usec, 0);
1280 			RACCT_UNLOCK();
1281 			PROC_UNLOCK(p);
1282 		}
1283 
1284 		/*
1285 		 * To ensure that processes are throttled in a fair way, we need
1286 		 * to iterate over all processes again and check the limits
1287 		 * for %cpu resource only after ucred racct containers have been
1288 		 * properly filled.
1289 		 */
1290 		FOREACH_PROC_IN_SYSTEM(p) {
1291 			PROC_LOCK(p);
1292 			if (p->p_state != PRS_NORMAL) {
1293 				PROC_UNLOCK(p);
1294 				continue;
1295 			}
1296 
1297 			if (racct_pcpu_available(p) <= 0) {
1298 				if (p->p_racct->r_resources[RACCT_PCTCPU] >
1299 				    pcpu_threshold)
1300 					racct_proc_throttle(p, -1);
1301 			} else if (p->p_throttled == -1) {
1302 				racct_proc_wakeup(p);
1303 			}
1304 			PROC_UNLOCK(p);
1305 		}
1306 		sx_sunlock(&allproc_lock);
1307 		pause("-", hz);
1308 	}
1309 }
1310 
1311 static struct kproc_desc racctd_kp = {
1312 	"racctd",
1313 	racctd,
1314 	NULL
1315 };
1316 
1317 static void
1318 racctd_init(void)
1319 {
1320 	if (!racct_enable)
1321 		return;
1322 
1323 	kproc_start(&racctd_kp);
1324 }
1325 SYSINIT(racctd, SI_SUB_RACCTD, SI_ORDER_FIRST, racctd_init, NULL);
1326 
1327 static void
1328 racct_init(void)
1329 {
1330 	if (!racct_enable)
1331 		return;
1332 
1333 	racct_zone = uma_zcreate("racct", sizeof(struct racct),
1334 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1335 	/*
1336 	 * XXX: Move this somewhere.
1337 	 */
1338 	prison0.pr_prison_racct = prison_racct_find("0");
1339 }
1340 SYSINIT(racct, SI_SUB_RACCT, SI_ORDER_FIRST, racct_init, NULL);
1341 
1342 #endif /* !RACCT */
1343