1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 * Copyright 2012 Joyent, Inc. All rights reserved.
25 */
26
27 #include <sys/types.h>
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/user.h>
31 #include <sys/proc.h>
32 #include <sys/cpuvar.h>
33 #include <sys/thread.h>
34 #include <sys/debug.h>
35 #include <sys/msacct.h>
36 #include <sys/time.h>
37 #include <sys/zone.h>
38
39 /*
40 * Mega-theory block comment:
41 *
42 * Microstate accounting uses finite states and the transitions between these
43 * states to measure timing and accounting information. The state information
44 * is presently tracked for threads (via microstate accounting) and cpus (via
45 * cpu microstate accounting). In each case, these accounting mechanisms use
46 * states and transitions to measure time spent in each state instead of
47 * clock-based sampling methodologies.
48 *
49 * For microstate accounting:
50 * state transitions are accomplished by calling new_mstate() to switch between
51 * states. Transitions from a sleeping state (LMS_SLEEP and LMS_STOPPED) occur
52 * by calling restore_mstate() which restores a thread to its previously running
53 * state. This code is primarialy executed by the dispatcher in disp() before
54 * running a process that was put to sleep. If the thread was not in a sleeping
55 * state, this call has little effect other than to update the count of time the
56 * thread has spent waiting on run-queues in its lifetime.
57 *
58 * For cpu microstate accounting:
59 * Cpu microstate accounting is similar to the microstate accounting for threads
60 * but it tracks user, system, and idle time for cpus. Cpu microstate
61 * accounting does not track interrupt times as there is a pre-existing
62 * interrupt accounting mechanism for this purpose. Cpu microstate accounting
63 * tracks time that user threads have spent active, idle, or in the system on a
64 * given cpu. Cpu microstate accounting has fewer states which allows it to
65 * have better defined transitions. The states transition in the following
66 * order:
67 *
68 * CMS_USER <-> CMS_SYSTEM <-> CMS_IDLE
69 *
70 * In order to get to the idle state, the cpu microstate must first go through
71 * the system state, and vice-versa for the user state from idle. The switching
72 * of the microstates from user to system is done as part of the regular thread
73 * microstate accounting code, except for the idle state which is switched by
74 * the dispatcher before it runs the idle loop.
75 *
76 * Cpu percentages:
77 * Cpu percentages are now handled by and based upon microstate accounting
78 * information (the same is true for load averages). The routines which handle
79 * the growing/shrinking and exponentiation of cpu percentages have been moved
80 * here as it now makes more sense for them to be generated from the microstate
81 * code. Cpu percentages are generated similarly to the way they were before;
82 * however, now they are based upon high-resolution timestamps and the
83 * timestamps are modified at various state changes instead of during a clock()
84 * interrupt. This allows us to generate more accurate cpu percentages which
85 * are also in-sync with microstate data.
86 */
87
88 /*
89 * Initialize the microstate level and the
90 * associated accounting information for an LWP.
91 */
92 void
93 init_mstate(
94 kthread_t *t,
95 int init_state)
96 {
97 struct mstate *ms;
98 klwp_t *lwp;
99 hrtime_t curtime;
100
101 ASSERT(init_state != LMS_WAIT_CPU);
102 ASSERT((unsigned)init_state < NMSTATES);
103
104 if ((lwp = ttolwp(t)) != NULL) {
105 ms = &lwp->lwp_mstate;
106 curtime = gethrtime_unscaled();
107 ms->ms_prev = LMS_SYSTEM;
108 ms->ms_start = curtime;
109 ms->ms_term = 0;
110 ms->ms_state_start = curtime;
111 t->t_mstate = init_state;
112 t->t_waitrq = 0;
113 t->t_hrtime = curtime;
114 if ((t->t_proc_flag & TP_MSACCT) == 0)
115 t->t_proc_flag |= TP_MSACCT;
116 bzero((caddr_t)&ms->ms_acct[0], sizeof (ms->ms_acct));
117 }
118 }
119
120 /*
121 * Initialize the microstate level and associated accounting information
122 * for the specified cpu
123 */
124
125 void
126 init_cpu_mstate(
127 cpu_t *cpu,
128 int init_state)
129 {
130 ASSERT(init_state != CMS_DISABLED);
131
132 cpu->cpu_mstate = init_state;
133 cpu->cpu_mstate_start = gethrtime_unscaled();
134 cpu->cpu_waitrq = 0;
135 bzero((caddr_t)&cpu->cpu_acct[0], sizeof (cpu->cpu_acct));
136 }
137
138 /*
139 * sets cpu state to OFFLINE. We don't actually track this time,
140 * but it serves as a useful placeholder state for when we're not
141 * doing anything.
142 */
143
144 void
145 term_cpu_mstate(struct cpu *cpu)
146 {
147 ASSERT(cpu->cpu_mstate != CMS_DISABLED);
148 cpu->cpu_mstate = CMS_DISABLED;
149 cpu->cpu_mstate_start = 0;
150 }
151
152 /* NEW_CPU_MSTATE comments inline in new_cpu_mstate below. */
153
154 #define NEW_CPU_MSTATE(state) \
155 gen = cpu->cpu_mstate_gen; \
156 cpu->cpu_mstate_gen = 0; \
157 /* Need membar_producer() here if stores not ordered / TSO */ \
158 cpu->cpu_acct[cpu->cpu_mstate] += curtime - cpu->cpu_mstate_start; \
159 cpu->cpu_mstate = state; \
160 cpu->cpu_mstate_start = curtime; \
161 /* Need membar_producer() here if stores not ordered / TSO */ \
162 cpu->cpu_mstate_gen = (++gen == 0) ? 1 : gen;
163
164 void
165 new_cpu_mstate(int cmstate, hrtime_t curtime)
166 {
167 cpu_t *cpu = CPU;
168 uint16_t gen;
169
170 ASSERT(cpu->cpu_mstate != CMS_DISABLED);
171 ASSERT(cmstate < NCMSTATES);
172 ASSERT(cmstate != CMS_DISABLED);
173
174 /*
175 * This function cannot be re-entrant on a given CPU. As such,
176 * we ASSERT and panic if we are called on behalf of an interrupt.
177 * The one exception is for an interrupt which has previously
178 * blocked. Such an interrupt is being scheduled by the dispatcher
179 * just like a normal thread, and as such cannot arrive here
180 * in a re-entrant manner.
181 */
182
183 ASSERT(!CPU_ON_INTR(cpu) && curthread->t_intr == NULL);
184 ASSERT(curthread->t_preempt > 0 || curthread == cpu->cpu_idle_thread);
185
186 /*
187 * LOCKING, or lack thereof:
188 *
189 * Updates to CPU mstate can only be made by the CPU
190 * itself, and the above check to ignore interrupts
191 * should prevent recursion into this function on a given
192 * processor. i.e. no possible write contention.
193 *
194 * However, reads of CPU mstate can occur at any time
195 * from any CPU. Any locking added to this code path
196 * would seriously impact syscall performance. So,
197 * instead we have a best-effort protection for readers.
198 * The reader will want to account for any time between
199 * cpu_mstate_start and the present time. This requires
200 * some guarantees that the reader is getting coherent
201 * information.
202 *
203 * We use a generation counter, which is set to 0 before
204 * we start making changes, and is set to a new value
205 * after we're done. Someone reading the CPU mstate
206 * should check for the same non-zero value of this
207 * counter both before and after reading all state. The
208 * important point is that the reader is not a
209 * performance-critical path, but this function is.
210 *
211 * The ordering of writes is critical. cpu_mstate_gen must
212 * be visibly zero on all CPUs before we change cpu_mstate
213 * and cpu_mstate_start. Additionally, cpu_mstate_gen must
214 * not be restored to oldgen+1 until after all of the other
215 * writes have become visible.
216 *
217 * Normally one puts membar_producer() calls to accomplish
218 * this. Unfortunately this routine is extremely performance
219 * critical (esp. in syscall_mstate below) and we cannot
220 * afford the additional time, particularly on some x86
221 * architectures with extremely slow sfence calls. On a
222 * CPU which guarantees write ordering (including sparc, x86,
223 * and amd64) this is not a problem. The compiler could still
224 * reorder the writes, so we make the four cpu fields
225 * volatile to prevent this.
226 *
227 * TSO warning: should we port to a non-TSO (or equivalent)
228 * CPU, this will break.
229 *
230 * The reader stills needs the membar_consumer() calls because,
231 * although the volatiles prevent the compiler from reordering
232 * loads, the CPU can still do so.
233 */
234
235 NEW_CPU_MSTATE(cmstate);
236 }
237
238 /*
239 * Return an aggregation of user and system CPU time consumed by
240 * the specified thread in scaled nanoseconds.
241 */
242 hrtime_t
243 mstate_thread_onproc_time(kthread_t *t)
244 {
245 hrtime_t aggr_time;
246 hrtime_t now;
247 hrtime_t waitrq;
248 hrtime_t state_start;
249 struct mstate *ms;
250 klwp_t *lwp;
251 int mstate;
252
253 ASSERT(THREAD_LOCK_HELD(t));
254
255 if ((lwp = ttolwp(t)) == NULL)
256 return (0);
257
258 mstate = t->t_mstate;
259 waitrq = t->t_waitrq;
260 ms = &lwp->lwp_mstate;
261 state_start = ms->ms_state_start;
262
263 aggr_time = ms->ms_acct[LMS_USER] +
264 ms->ms_acct[LMS_SYSTEM] + ms->ms_acct[LMS_TRAP];
265
266 now = gethrtime_unscaled();
267
268 /*
269 * NOTE: gethrtime_unscaled on X86 taken on different CPUs is
270 * inconsistent, so it is possible that now < state_start.
271 */
272 if (mstate == LMS_USER || mstate == LMS_SYSTEM || mstate == LMS_TRAP) {
273 /* if waitrq is zero, count all of the time. */
274 if (waitrq == 0) {
275 waitrq = now;
276 }
277
278 if (waitrq > state_start) {
279 aggr_time += waitrq - state_start;
280 }
281 }
282
283 scalehrtime(&aggr_time);
284 return (aggr_time);
285 }
286
287 /*
288 * Return the amount of onproc and runnable time this thread has experienced.
289 *
290 * Because the fields we read are not protected by locks when updated
291 * by the thread itself, this is an inherently racey interface. In
292 * particular, the ASSERT(THREAD_LOCK_HELD(t)) doesn't guarantee as much
293 * as it might appear to.
294 *
295 * The implication for users of this interface is that onproc and runnable
296 * are *NOT* monotonically increasing; they may temporarily be larger than
297 * they should be.
298 */
299 void
300 mstate_systhread_times(kthread_t *t, hrtime_t *onproc, hrtime_t *runnable)
301 {
302 struct mstate *const ms = &ttolwp(t)->lwp_mstate;
303
304 int mstate;
305 hrtime_t now;
306 hrtime_t state_start;
307 hrtime_t waitrq;
308 hrtime_t aggr_onp;
309 hrtime_t aggr_run;
310
311 ASSERT(THREAD_LOCK_HELD(t));
312 ASSERT(t->t_procp->p_flag & SSYS);
313 ASSERT(ttolwp(t) != NULL);
314
315 /* shouldn't be any non-SYSTEM on-CPU time */
316 ASSERT(ms->ms_acct[LMS_USER] == 0);
317 ASSERT(ms->ms_acct[LMS_TRAP] == 0);
318
319 mstate = t->t_mstate;
320 waitrq = t->t_waitrq;
321 state_start = ms->ms_state_start;
322
323 aggr_onp = ms->ms_acct[LMS_SYSTEM];
324 aggr_run = ms->ms_acct[LMS_WAIT_CPU];
325
326 now = gethrtime_unscaled();
327
328 /* if waitrq == 0, then there is no time to account to TS_RUN */
329 if (waitrq == 0)
330 waitrq = now;
331
332 /* If there is system time to accumulate, do so */
333 if (mstate == LMS_SYSTEM && state_start < waitrq)
334 aggr_onp += waitrq - state_start;
335
336 if (waitrq < now)
337 aggr_run += now - waitrq;
338
339 scalehrtime(&aggr_onp);
340 scalehrtime(&aggr_run);
341
342 *onproc = aggr_onp;
343 *runnable = aggr_run;
344 }
345
346 /*
347 * Return an aggregation of microstate times in scaled nanoseconds (high-res
348 * time). This keeps in mind that p_acct is already scaled, and ms_acct is
349 * not.
350 */
351 hrtime_t
352 mstate_aggr_state(proc_t *p, int a_state)
353 {
354 struct mstate *ms;
355 kthread_t *t;
356 klwp_t *lwp;
357 hrtime_t aggr_time;
358 hrtime_t scaledtime;
359
360 ASSERT(MUTEX_HELD(&p->p_lock));
361 ASSERT((unsigned)a_state < NMSTATES);
362
363 aggr_time = p->p_acct[a_state];
364 if (a_state == LMS_SYSTEM)
365 aggr_time += p->p_acct[LMS_TRAP];
366
367 t = p->p_tlist;
368 if (t == NULL)
369 return (aggr_time);
370
371 do {
372 if (t->t_proc_flag & TP_LWPEXIT)
373 continue;
374
375 lwp = ttolwp(t);
376 ms = &lwp->lwp_mstate;
377 scaledtime = ms->ms_acct[a_state];
378 scalehrtime(&scaledtime);
379 aggr_time += scaledtime;
380 if (a_state == LMS_SYSTEM) {
381 scaledtime = ms->ms_acct[LMS_TRAP];
382 scalehrtime(&scaledtime);
383 aggr_time += scaledtime;
384 }
385 } while ((t = t->t_forw) != p->p_tlist);
386
387 return (aggr_time);
388 }
389
390
391 void
392 syscall_mstate(int fromms, int toms)
393 {
394 kthread_t *t = curthread;
395 zone_t *z = ttozone(t);
396 struct mstate *ms;
397 hrtime_t *mstimep;
398 hrtime_t curtime;
399 klwp_t *lwp;
400 hrtime_t newtime;
401 cpu_t *cpu;
402 uint16_t gen;
403
404 if ((lwp = ttolwp(t)) == NULL)
405 return;
406
407 ASSERT(fromms < NMSTATES);
408 ASSERT(toms < NMSTATES);
409
410 ms = &lwp->lwp_mstate;
411 mstimep = &ms->ms_acct[fromms];
412 curtime = gethrtime_unscaled();
413 newtime = curtime - ms->ms_state_start;
414 while (newtime < 0) {
415 curtime = gethrtime_unscaled();
416 newtime = curtime - ms->ms_state_start;
417 }
418 *mstimep += newtime;
419 if (fromms == LMS_USER)
420 atomic_add_64(&z->zone_utime, newtime);
421 else if (fromms == LMS_SYSTEM)
422 atomic_add_64(&z->zone_stime, newtime);
423 t->t_mstate = toms;
424 ms->ms_state_start = curtime;
425 ms->ms_prev = fromms;
426 kpreempt_disable(); /* don't change CPU while changing CPU's state */
427 cpu = CPU;
428 ASSERT(cpu == t->t_cpu);
429 if ((toms != LMS_USER) && (cpu->cpu_mstate != CMS_SYSTEM)) {
430 NEW_CPU_MSTATE(CMS_SYSTEM);
431 } else if ((toms == LMS_USER) && (cpu->cpu_mstate != CMS_USER)) {
432 NEW_CPU_MSTATE(CMS_USER);
433 }
434 kpreempt_enable();
435 }
436
437 #undef NEW_CPU_MSTATE
438
439 /*
440 * The following is for computing the percentage of cpu time used recently
441 * by an lwp. The function cpu_decay() is also called from /proc code.
442 *
443 * exp_x(x):
444 * Given x as a 64-bit non-negative scaled integer of arbitrary magnitude,
445 * Return exp(-x) as a 64-bit scaled integer in the range [0 .. 1].
446 *
447 * Scaling for 64-bit scaled integer:
448 * The binary point is to the right of the high-order bit
449 * of the low-order 32-bit word.
450 */
451
452 #define LSHIFT 31
453 #define LSI_ONE ((uint32_t)1 << LSHIFT) /* 32-bit scaled integer 1 */
454
455 #ifdef DEBUG
456 uint_t expx_cnt = 0; /* number of calls to exp_x() */
457 uint_t expx_mul = 0; /* number of long multiplies in exp_x() */
458 #endif
459
460 static uint64_t
461 exp_x(uint64_t x)
462 {
463 int i;
464 uint64_t ull;
465 uint32_t ui;
466
467 #ifdef DEBUG
468 expx_cnt++;
469 #endif
470 /*
471 * By the formula:
472 * exp(-x) = exp(-x/2) * exp(-x/2)
473 * we keep halving x until it becomes small enough for
474 * the following approximation to be accurate enough:
475 * exp(-x) = 1 - x
476 * We reduce x until it is less than 1/4 (the 2 in LSHIFT-2 below).
477 * Our final error will be smaller than 4% .
478 */
479
480 /*
481 * Use a uint64_t for the initial shift calculation.
482 */
483 ull = x >> (LSHIFT-2);
484
485 /*
486 * Short circuit:
487 * A number this large produces effectively 0 (actually .005).
488 * This way, we will never do more than 5 multiplies.
489 */
490 if (ull >= (1 << 5))
491 return (0);
492
493 ui = ull; /* OK. Now we can use a uint_t. */
494 for (i = 0; ui != 0; i++)
495 ui >>= 1;
496
497 if (i != 0) {
498 #ifdef DEBUG
499 expx_mul += i; /* seldom happens */
500 #endif
501 x >>= i;
502 }
503
504 /*
505 * Now we compute 1 - x and square it the number of times
506 * that we halved x above to produce the final result:
507 */
508 x = LSI_ONE - x;
509 while (i--)
510 x = (x * x) >> LSHIFT;
511
512 return (x);
513 }
514
515 /*
516 * Given the old percent cpu and a time delta in nanoseconds,
517 * return the new decayed percent cpu: pct * exp(-tau),
518 * where 'tau' is the time delta multiplied by a decay factor.
519 * We have chosen the decay factor (cpu_decay_factor in param.c)
520 * to make the decay over five seconds be approximately 20%.
521 *
522 * 'pct' is a 32-bit scaled integer <= 1
523 * The binary point is to the right of the high-order bit
524 * of the 32-bit word.
525 */
526 static uint32_t
527 cpu_decay(uint32_t pct, hrtime_t nsec)
528 {
529 uint64_t delta = (uint64_t)nsec;
530
531 delta /= cpu_decay_factor;
532 return ((pct * exp_x(delta)) >> LSHIFT);
533 }
534
535 /*
536 * Given the old percent cpu and a time delta in nanoseconds,
537 * return the new grown percent cpu: 1 - ( 1 - pct ) * exp(-tau)
538 */
539 static uint32_t
540 cpu_grow(uint32_t pct, hrtime_t nsec)
541 {
542 return (LSI_ONE - cpu_decay(LSI_ONE - pct, nsec));
543 }
544
545
546 /*
547 * Defined to determine whether a lwp is still on a processor.
548 */
549
550 #define T_ONPROC(kt) \
551 ((kt)->t_mstate < LMS_SLEEP)
552 #define T_OFFPROC(kt) \
553 ((kt)->t_mstate >= LMS_SLEEP)
554
555 uint_t
556 cpu_update_pct(kthread_t *t, hrtime_t newtime)
557 {
558 hrtime_t delta;
559 hrtime_t hrlb;
560 uint_t pctcpu;
561 uint_t npctcpu;
562
563 /*
564 * This routine can get called at PIL > 0, this *has* to be
565 * done atomically. Holding locks here causes bad things to happen.
566 * (read: deadlock).
567 */
568
569 do {
570 pctcpu = t->t_pctcpu;
571 hrlb = t->t_hrtime;
572 delta = newtime - hrlb;
573 if (delta < 0) {
574 newtime = gethrtime_unscaled();
575 delta = newtime - hrlb;
576 }
577 t->t_hrtime = newtime;
578 scalehrtime(&delta);
579 if (T_ONPROC(t) && t->t_waitrq == 0) {
580 npctcpu = cpu_grow(pctcpu, delta);
581 } else {
582 npctcpu = cpu_decay(pctcpu, delta);
583 }
584 } while (atomic_cas_32(&t->t_pctcpu, pctcpu, npctcpu) != pctcpu);
585
586 return (npctcpu);
587 }
588
589 /*
590 * Change the microstate level for the LWP and update the
591 * associated accounting information. Return the previous
592 * LWP state.
593 */
594 int
595 new_mstate(kthread_t *t, int new_state)
596 {
597 struct mstate *ms;
598 unsigned state;
599 hrtime_t *mstimep;
600 hrtime_t curtime;
601 hrtime_t newtime;
602 hrtime_t oldtime;
603 hrtime_t ztime;
604 hrtime_t origstart;
605 klwp_t *lwp;
606 zone_t *z;
607
608 ASSERT(new_state != LMS_WAIT_CPU);
609 ASSERT((unsigned)new_state < NMSTATES);
610 ASSERT(t == curthread || THREAD_LOCK_HELD(t));
611
612 /*
613 * Don't do microstate processing for threads without a lwp (kernel
614 * threads). Also, if we're an interrupt thread that is pinning another
615 * thread, our t_mstate hasn't been initialized. We'd be modifying the
616 * microstate of the underlying lwp which doesn't realize that it's
617 * pinned. In this case, also don't change the microstate.
618 */
619 if (((lwp = ttolwp(t)) == NULL) || t->t_intr)
620 return (LMS_SYSTEM);
621
622 curtime = gethrtime_unscaled();
623
624 /* adjust cpu percentages before we go any further */
625 (void) cpu_update_pct(t, curtime);
626
627 ms = &lwp->lwp_mstate;
628 state = t->t_mstate;
629 origstart = ms->ms_state_start;
630 do {
631 switch (state) {
632 case LMS_TFAULT:
633 case LMS_DFAULT:
634 case LMS_KFAULT:
635 case LMS_USER_LOCK:
636 mstimep = &ms->ms_acct[LMS_SYSTEM];
637 break;
638 default:
639 mstimep = &ms->ms_acct[state];
640 break;
641 }
642 ztime = newtime = curtime - ms->ms_state_start;
643 if (newtime < 0) {
644 curtime = gethrtime_unscaled();
645 oldtime = *mstimep - 1; /* force CAS to fail */
646 continue;
647 }
648 oldtime = *mstimep;
649 newtime += oldtime;
650 t->t_mstate = new_state;
651 ms->ms_state_start = curtime;
652 } while (atomic_cas_64((uint64_t *)mstimep, oldtime, newtime) !=
653 oldtime);
654
655 /*
656 * When the system boots the initial startup thread will have a
657 * ms_state_start of 0 which would add a huge system time to the global
658 * zone. We want to skip aggregating that initial bit of work.
659 */
660 if (origstart != 0) {
661 z = ttozone(t);
662 if (state == LMS_USER)
663 atomic_add_64(&z->zone_utime, ztime);
664 else if (state == LMS_SYSTEM)
665 atomic_add_64(&z->zone_stime, ztime);
666 }
667
668 /*
669 * Remember the previous running microstate.
670 */
671 if (state != LMS_SLEEP && state != LMS_STOPPED)
672 ms->ms_prev = state;
673
674 /*
675 * Switch CPU microstate if appropriate
676 */
677
678 kpreempt_disable(); /* MUST disable kpreempt before touching t->cpu */
679 ASSERT(t->t_cpu == CPU);
680 if (!CPU_ON_INTR(t->t_cpu) && curthread->t_intr == NULL) {
681 if (new_state == LMS_USER && t->t_cpu->cpu_mstate != CMS_USER)
682 new_cpu_mstate(CMS_USER, curtime);
683 else if (new_state != LMS_USER &&
684 t->t_cpu->cpu_mstate != CMS_SYSTEM)
685 new_cpu_mstate(CMS_SYSTEM, curtime);
686 }
687 kpreempt_enable();
688
689 return (ms->ms_prev);
690 }
691
692 /*
693 * Restore the LWP microstate to the previous runnable state.
694 * Called from disp() with the newly selected lwp.
695 */
696 void
697 restore_mstate(kthread_t *t)
698 {
699 struct mstate *ms;
700 hrtime_t *mstimep;
701 klwp_t *lwp;
702 hrtime_t curtime;
703 hrtime_t waitrq;
704 hrtime_t newtime;
705 hrtime_t oldtime;
706 hrtime_t waittime;
707 zone_t *z;
708
709 /*
710 * Don't call restore mstate of threads without lwps. (Kernel threads)
711 *
712 * threads with t_intr set shouldn't be in the dispatcher, so assert
713 * that nobody here has t_intr.
714 */
715 ASSERT(t->t_intr == NULL);
716
717 if ((lwp = ttolwp(t)) == NULL)
718 return;
719
720 curtime = gethrtime_unscaled();
721 (void) cpu_update_pct(t, curtime);
722 ms = &lwp->lwp_mstate;
723 ASSERT((unsigned)t->t_mstate < NMSTATES);
724 do {
725 switch (t->t_mstate) {
726 case LMS_SLEEP:
727 /*
728 * Update the timer for the current sleep state.
729 */
730 ASSERT((unsigned)ms->ms_prev < NMSTATES);
731 switch (ms->ms_prev) {
732 case LMS_TFAULT:
733 case LMS_DFAULT:
734 case LMS_KFAULT:
735 case LMS_USER_LOCK:
736 mstimep = &ms->ms_acct[ms->ms_prev];
737 break;
738 default:
739 mstimep = &ms->ms_acct[LMS_SLEEP];
740 break;
741 }
742 /*
743 * Return to the previous run state.
744 */
745 t->t_mstate = ms->ms_prev;
746 break;
747 case LMS_STOPPED:
748 mstimep = &ms->ms_acct[LMS_STOPPED];
749 /*
750 * Return to the previous run state.
751 */
752 t->t_mstate = ms->ms_prev;
753 break;
754 case LMS_TFAULT:
755 case LMS_DFAULT:
756 case LMS_KFAULT:
757 case LMS_USER_LOCK:
758 mstimep = &ms->ms_acct[LMS_SYSTEM];
759 break;
760 default:
761 mstimep = &ms->ms_acct[t->t_mstate];
762 break;
763 }
764 waitrq = t->t_waitrq; /* hopefully atomic */
765 if (waitrq == 0) {
766 waitrq = curtime;
767 }
768 t->t_waitrq = 0;
769 newtime = waitrq - ms->ms_state_start;
770 if (newtime < 0) {
771 curtime = gethrtime_unscaled();
772 oldtime = *mstimep - 1; /* force CAS to fail */
773 continue;
774 }
775 oldtime = *mstimep;
776 newtime += oldtime;
777 } while (atomic_cas_64((uint64_t *)mstimep, oldtime, newtime) !=
778 oldtime);
779
780 /*
781 * Update the WAIT_CPU timer and per-cpu waitrq total.
782 */
783 z = ttozone(t);
784 waittime = curtime - waitrq;
785 ms->ms_acct[LMS_WAIT_CPU] += waittime;
786 atomic_add_64(&z->zone_wtime, waittime);
787 CPU->cpu_waitrq += waittime;
788 ms->ms_state_start = curtime;
789 }
790
791 /*
792 * Copy lwp microstate accounting and resource usage information
793 * to the process. (lwp is terminating)
794 */
795 void
796 term_mstate(kthread_t *t)
797 {
798 struct mstate *ms;
799 proc_t *p = ttoproc(t);
800 klwp_t *lwp = ttolwp(t);
801 int i;
802 hrtime_t tmp;
803
804 ASSERT(MUTEX_HELD(&p->p_lock));
805
806 ms = &lwp->lwp_mstate;
807 (void) new_mstate(t, LMS_STOPPED);
808 ms->ms_term = ms->ms_state_start;
809 tmp = ms->ms_term - ms->ms_start;
810 scalehrtime(&tmp);
811 p->p_mlreal += tmp;
812 for (i = 0; i < NMSTATES; i++) {
813 tmp = ms->ms_acct[i];
814 scalehrtime(&tmp);
815 p->p_acct[i] += tmp;
816 }
817 p->p_ru.minflt += lwp->lwp_ru.minflt;
818 p->p_ru.majflt += lwp->lwp_ru.majflt;
819 p->p_ru.nswap += lwp->lwp_ru.nswap;
820 p->p_ru.inblock += lwp->lwp_ru.inblock;
821 p->p_ru.oublock += lwp->lwp_ru.oublock;
822 p->p_ru.msgsnd += lwp->lwp_ru.msgsnd;
823 p->p_ru.msgrcv += lwp->lwp_ru.msgrcv;
824 p->p_ru.nsignals += lwp->lwp_ru.nsignals;
825 p->p_ru.nvcsw += lwp->lwp_ru.nvcsw;
826 p->p_ru.nivcsw += lwp->lwp_ru.nivcsw;
827 p->p_ru.sysc += lwp->lwp_ru.sysc;
828 p->p_ru.ioch += lwp->lwp_ru.ioch;
829 p->p_defunct++;
830 }