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1 /*
2 * CDDL HEADER START
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.
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.
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]
19 * CDDL HEADER END
21 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
22 /* All Rights Reserved */
25 * Copyright (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved.
28 #include <sys/param.h>
29 #include <sys/t_lock.h>
30 #include <sys/types.h>
31 #include <sys/tuneable.h>
32 #include <sys/sysmacros.h>
33 #include <sys/systm.h>
34 #include <sys/cpuvar.h>
35 #include <sys/lgrp.h>
36 #include <sys/user.h>
37 #include <sys/proc.h>
38 #include <sys/callo.h>
39 #include <sys/kmem.h>
40 #include <sys/var.h>
41 #include <sys/cmn_err.h>
42 #include <sys/swap.h>
43 #include <sys/vmsystm.h>
44 #include <sys/class.h>
45 #include <sys/time.h>
46 #include <sys/debug.h>
47 #include <sys/vtrace.h>
48 #include <sys/spl.h>
49 #include <sys/atomic.h>
50 #include <sys/dumphdr.h>
51 #include <sys/archsystm.h>
52 #include <sys/fs/swapnode.h>
53 #include <sys/panic.h>
54 #include <sys/disp.h>
55 #include <sys/msacct.h>
56 #include <sys/mem_cage.h>
58 #include <vm/page.h>
59 #include <vm/anon.h>
60 #include <vm/rm.h>
61 #include <sys/cyclic.h>
62 #include <sys/cpupart.h>
63 #include <sys/rctl.h>
64 #include <sys/task.h>
65 #include <sys/sdt.h>
66 #include <sys/ddi_timer.h>
67 #include <sys/random.h>
68 #include <sys/modctl.h>
71 * for NTP support
73 #include <sys/timex.h>
74 #include <sys/inttypes.h>
76 #include <sys/sunddi.h>
77 #include <sys/clock_impl.h>
80 * clock() is called straight from the clock cyclic; see clock_init().
82 * Functions:
83 * reprime clock
84 * maintain date
85 * jab the scheduler
88 extern kcondvar_t fsflush_cv;
89 extern sysinfo_t sysinfo;
90 extern vminfo_t vminfo;
91 extern int idleswtch; /* flag set while idle in pswtch() */
92 extern hrtime_t volatile devinfo_freeze;
95 * high-precision avenrun values. These are needed to make the
96 * regular avenrun values accurate.
98 static uint64_t hp_avenrun[3];
99 int avenrun[3]; /* FSCALED average run queue lengths */
100 time_t time; /* time in seconds since 1970 - for compatibility only */
102 static struct loadavg_s loadavg;
104 * Phase/frequency-lock loop (PLL/FLL) definitions
106 * The following variables are read and set by the ntp_adjtime() system
107 * call.
109 * time_state shows the state of the system clock, with values defined
110 * in the timex.h header file.
112 * time_status shows the status of the system clock, with bits defined
113 * in the timex.h header file.
115 * time_offset is used by the PLL/FLL to adjust the system time in small
116 * increments.
118 * time_constant determines the bandwidth or "stiffness" of the PLL.
120 * time_tolerance determines maximum frequency error or tolerance of the
121 * CPU clock oscillator and is a property of the architecture; however,
122 * in principle it could change as result of the presence of external
123 * discipline signals, for instance.
125 * time_precision is usually equal to the kernel tick variable; however,
126 * in cases where a precision clock counter or external clock is
127 * available, the resolution can be much less than this and depend on
128 * whether the external clock is working or not.
130 * time_maxerror is initialized by a ntp_adjtime() call and increased by
131 * the kernel once each second to reflect the maximum error bound
132 * growth.
134 * time_esterror is set and read by the ntp_adjtime() call, but
135 * otherwise not used by the kernel.
137 int32_t time_state = TIME_OK; /* clock state */
138 int32_t time_status = STA_UNSYNC; /* clock status bits */
139 int32_t time_offset = 0; /* time offset (us) */
140 int32_t time_constant = 0; /* pll time constant */
141 int32_t time_tolerance = MAXFREQ; /* frequency tolerance (scaled ppm) */
142 int32_t time_precision = 1; /* clock precision (us) */
143 int32_t time_maxerror = MAXPHASE; /* maximum error (us) */
144 int32_t time_esterror = MAXPHASE; /* estimated error (us) */
147 * The following variables establish the state of the PLL/FLL and the
148 * residual time and frequency offset of the local clock. The scale
149 * factors are defined in the timex.h header file.
151 * time_phase and time_freq are the phase increment and the frequency
152 * increment, respectively, of the kernel time variable.
154 * time_freq is set via ntp_adjtime() from a value stored in a file when
155 * the synchronization daemon is first started. Its value is retrieved
156 * via ntp_adjtime() and written to the file about once per hour by the
157 * daemon.
159 * time_adj is the adjustment added to the value of tick at each timer
160 * interrupt and is recomputed from time_phase and time_freq at each
161 * seconds rollover.
163 * time_reftime is the second's portion of the system time at the last
164 * call to ntp_adjtime(). It is used to adjust the time_freq variable
165 * and to increase the time_maxerror as the time since last update
166 * increases.
168 int32_t time_phase = 0; /* phase offset (scaled us) */
169 int32_t time_freq = 0; /* frequency offset (scaled ppm) */
170 int32_t time_adj = 0; /* tick adjust (scaled 1 / hz) */
171 int32_t time_reftime = 0; /* time at last adjustment (s) */
174 * The scale factors of the following variables are defined in the
175 * timex.h header file.
177 * pps_time contains the time at each calibration interval, as read by
178 * microtime(). pps_count counts the seconds of the calibration
179 * interval, the duration of which is nominally pps_shift in powers of
180 * two.
182 * pps_offset is the time offset produced by the time median filter
183 * pps_tf[], while pps_jitter is the dispersion (jitter) measured by
184 * this filter.
186 * pps_freq is the frequency offset produced by the frequency median
187 * filter pps_ff[], while pps_stabil is the dispersion (wander) measured
188 * by this filter.
190 * pps_usec is latched from a high resolution counter or external clock
191 * at pps_time. Here we want the hardware counter contents only, not the
192 * contents plus the time_tv.usec as usual.
194 * pps_valid counts the number of seconds since the last PPS update. It
195 * is used as a watchdog timer to disable the PPS discipline should the
196 * PPS signal be lost.
198 * pps_glitch counts the number of seconds since the beginning of an
199 * offset burst more than tick/2 from current nominal offset. It is used
200 * mainly to suppress error bursts due to priority conflicts between the
201 * PPS interrupt and timer interrupt.
203 * pps_intcnt counts the calibration intervals for use in the interval-
204 * adaptation algorithm. It's just too complicated for words.
206 struct timeval pps_time; /* kernel time at last interval */
207 int32_t pps_tf[] = {0, 0, 0}; /* pps time offset median filter (us) */
208 int32_t pps_offset = 0; /* pps time offset (us) */
209 int32_t pps_jitter = MAXTIME; /* time dispersion (jitter) (us) */
210 int32_t pps_ff[] = {0, 0, 0}; /* pps frequency offset median filter */
211 int32_t pps_freq = 0; /* frequency offset (scaled ppm) */
212 int32_t pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */
213 int32_t pps_usec = 0; /* microsec counter at last interval */
214 int32_t pps_valid = PPS_VALID; /* pps signal watchdog counter */
215 int32_t pps_glitch = 0; /* pps signal glitch counter */
216 int32_t pps_count = 0; /* calibration interval counter (s) */
217 int32_t pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */
218 int32_t pps_intcnt = 0; /* intervals at current duration */
221 * PPS signal quality monitors
223 * pps_jitcnt counts the seconds that have been discarded because the
224 * jitter measured by the time median filter exceeds the limit MAXTIME
225 * (100 us).
227 * pps_calcnt counts the frequency calibration intervals, which are
228 * variable from 4 s to 256 s.
230 * pps_errcnt counts the calibration intervals which have been discarded
231 * because the wander exceeds the limit MAXFREQ (100 ppm) or where the
232 * calibration interval jitter exceeds two ticks.
234 * pps_stbcnt counts the calibration intervals that have been discarded
235 * because the frequency wander exceeds the limit MAXFREQ / 4 (25 us).
237 int32_t pps_jitcnt = 0; /* jitter limit exceeded */
238 int32_t pps_calcnt = 0; /* calibration intervals */
239 int32_t pps_errcnt = 0; /* calibration errors */
240 int32_t pps_stbcnt = 0; /* stability limit exceeded */
242 kcondvar_t lbolt_cv;
245 * Hybrid lbolt implementation:
247 * The service historically provided by the lbolt and lbolt64 variables has
248 * been replaced by the ddi_get_lbolt() and ddi_get_lbolt64() routines, and the
249 * original symbols removed from the system. The once clock driven variables are
250 * now implemented in an event driven fashion, backed by gethrtime() coarsed to
251 * the appropriate clock resolution. The default event driven implementation is
252 * complemented by a cyclic driven one, active only during periods of intense
253 * activity around the DDI lbolt routines, when a lbolt specific cyclic is
254 * reprogramed to fire at a clock tick interval to serve consumers of lbolt who
255 * rely on the original low cost of consulting a memory position.
257 * The implementation uses the number of calls to these routines and the
258 * frequency of these to determine when to transition from event to cyclic
259 * driven and vice-versa. These values are kept on a per CPU basis for
260 * scalability reasons and to prevent CPUs from constantly invalidating a single
261 * cache line when modifying a global variable. The transition from event to
262 * cyclic mode happens once the thresholds are crossed, and activity on any CPU
263 * can cause such transition.
265 * The lbolt_hybrid function pointer is called by ddi_get_lbolt() and
266 * ddi_get_lbolt64(), and will point to lbolt_event_driven() or
267 * lbolt_cyclic_driven() according to the current mode. When the thresholds
268 * are exceeded, lbolt_event_driven() will reprogram the lbolt cyclic to
269 * fire at a nsec_per_tick interval and increment an internal variable at
270 * each firing. lbolt_hybrid will then point to lbolt_cyclic_driven(), which
271 * will simply return the value of such variable. lbolt_cyclic() will attempt
272 * to shut itself off at each threshold interval (sampling period for calls
273 * to the DDI lbolt routines), and return to the event driven mode, but will
274 * be prevented from doing so if lbolt_cyclic_driven() is being heavily used.
276 * lbolt_bootstrap is used during boot to serve lbolt consumers who don't wait
277 * for the cyclic subsystem to be intialized.
280 int64_t lbolt_bootstrap(void);
281 int64_t lbolt_event_driven(void);
282 int64_t lbolt_cyclic_driven(void);
283 int64_t (*lbolt_hybrid)(void) = lbolt_bootstrap;
284 uint_t lbolt_ev_to_cyclic(caddr_t, caddr_t);
287 * lbolt's cyclic, installed by clock_init().
289 static void lbolt_cyclic(void);
292 * Tunable to keep lbolt in cyclic driven mode. This will prevent the system
293 * from switching back to event driven, once it reaches cyclic mode.
295 static boolean_t lbolt_cyc_only = B_FALSE;
298 * Cache aligned, per CPU structure with lbolt usage statistics.
300 static lbolt_cpu_t *lb_cpu;
303 * Single, cache aligned, structure with all the information required by
304 * the lbolt implementation.
306 lbolt_info_t *lb_info;
309 int one_sec = 1; /* turned on once every second */
310 static int fsflushcnt; /* counter for t_fsflushr */
311 int dosynctodr = 1; /* patchable; enable/disable sync to TOD chip */
312 int tod_needsync = 0; /* need to sync tod chip with software time */
313 static int tod_broken = 0; /* clock chip doesn't work */
314 time_t boot_time = 0; /* Boot time in seconds since 1970 */
315 cyclic_id_t clock_cyclic; /* clock()'s cyclic_id */
316 cyclic_id_t deadman_cyclic; /* deadman()'s cyclic_id */
317 cyclic_id_t ddi_timer_cyclic; /* cyclic_timer()'s cyclic_id */
319 extern void clock_tick_schedule(int);
321 static int lgrp_ticks; /* counter to schedule lgrp load calcs */
324 * for tod fault detection
326 #define TOD_REF_FREQ ((longlong_t)(NANOSEC))
327 #define TOD_STALL_THRESHOLD (TOD_REF_FREQ * 3 / 2)
328 #define TOD_JUMP_THRESHOLD (TOD_REF_FREQ / 2)
329 #define TOD_FILTER_N 4
330 #define TOD_FILTER_SETTLE (4 * TOD_FILTER_N)
331 static int tod_faulted = TOD_NOFAULT;
333 static int tod_status_flag = 0; /* used by tod_validate() */
335 static hrtime_t prev_set_tick = 0; /* gethrtime() prior to tod_set() */
336 static time_t prev_set_tod = 0; /* tv_sec value passed to tod_set() */
338 /* patchable via /etc/system */
339 int tod_validate_enable = 1;
341 /* Diagnose/Limit messages about delay(9F) called from interrupt context */
342 int delay_from_interrupt_diagnose = 0;
343 volatile uint32_t delay_from_interrupt_msg = 20;
346 * On non-SPARC systems, TOD validation must be deferred until gethrtime
347 * returns non-zero values (after mach_clkinit's execution).
348 * On SPARC systems, it must be deferred until after hrtime_base
349 * and hres_last_tick are set (in the first invocation of hres_tick).
350 * Since in both cases the prerequisites occur before the invocation of
351 * tod_get() in clock(), the deferment is lifted there.
353 static boolean_t tod_validate_deferred = B_TRUE;
356 * tod_fault_table[] must be aligned with
357 * enum tod_fault_type in systm.h
359 static char *tod_fault_table[] = {
360 "Reversed", /* TOD_REVERSED */
361 "Stalled", /* TOD_STALLED */
362 "Jumped", /* TOD_JUMPED */
363 "Changed in Clock Rate", /* TOD_RATECHANGED */
364 "Is Read-Only" /* TOD_RDONLY */
366 * no strings needed for TOD_NOFAULT
371 * test hook for tod broken detection in tod_validate
373 int tod_unit_test = 0;
374 time_t tod_test_injector;
376 #define CLOCK_ADJ_HIST_SIZE 4
378 static int adj_hist_entry;
380 int64_t clock_adj_hist[CLOCK_ADJ_HIST_SIZE];
382 static void calcloadavg(int, uint64_t *);
383 static int genloadavg(struct loadavg_s *);
384 static void loadavg_update();
386 void (*cmm_clock_callout)() = NULL;
387 void (*cpucaps_clock_callout)() = NULL;
389 extern clock_t clock_tick_proc_max;
391 static int64_t deadman_counter = 0;
393 static void
394 clock(void)
396 kthread_t *t;
397 uint_t nrunnable;
398 uint_t w_io;
399 cpu_t *cp;
400 cpupart_t *cpupart;
401 extern void set_freemem();
402 void (*funcp)();
403 int32_t ltemp;
404 int64_t lltemp;
405 int s;
406 int do_lgrp_load;
407 int i;
408 clock_t now = LBOLT_NO_ACCOUNT; /* current tick */
410 if (panicstr)
411 return;
414 * Make sure that 'freemem' do not drift too far from the truth
416 set_freemem();
420 * Before the section which is repeated is executed, we do
421 * the time delta processing which occurs every clock tick
423 * There is additional processing which happens every time
424 * the nanosecond counter rolls over which is described
425 * below - see the section which begins with : if (one_sec)
427 * This section marks the beginning of the precision-kernel
428 * code fragment.
430 * First, compute the phase adjustment. If the low-order bits
431 * (time_phase) of the update overflow, bump the higher order
432 * bits (time_update).
434 time_phase += time_adj;
435 if (time_phase <= -FINEUSEC) {
436 ltemp = -time_phase / SCALE_PHASE;
437 time_phase += ltemp * SCALE_PHASE;
438 s = hr_clock_lock();
439 timedelta -= ltemp * (NANOSEC/MICROSEC);
440 hr_clock_unlock(s);
441 } else if (time_phase >= FINEUSEC) {
442 ltemp = time_phase / SCALE_PHASE;
443 time_phase -= ltemp * SCALE_PHASE;
444 s = hr_clock_lock();
445 timedelta += ltemp * (NANOSEC/MICROSEC);
446 hr_clock_unlock(s);
450 * End of precision-kernel code fragment which is processed
451 * every timer interrupt.
453 * Continue with the interrupt processing as scheduled.
456 * Count the number of runnable threads and the number waiting
457 * for some form of I/O to complete -- gets added to
458 * sysinfo.waiting. To know the state of the system, must add
459 * wait counts from all CPUs. Also add up the per-partition
460 * statistics.
462 w_io = 0;
463 nrunnable = 0;
466 * keep track of when to update lgrp/part loads
469 do_lgrp_load = 0;
470 if (lgrp_ticks++ >= hz / 10) {
471 lgrp_ticks = 0;
472 do_lgrp_load = 1;
475 if (one_sec) {
476 loadavg_update();
477 deadman_counter++;
481 * First count the threads waiting on kpreempt queues in each
482 * CPU partition.
485 cpupart = cp_list_head;
486 do {
487 uint_t cpupart_nrunnable = cpupart->cp_kp_queue.disp_nrunnable;
489 cpupart->cp_updates++;
490 nrunnable += cpupart_nrunnable;
491 cpupart->cp_nrunnable_cum += cpupart_nrunnable;
492 if (one_sec) {
493 cpupart->cp_nrunning = 0;
494 cpupart->cp_nrunnable = cpupart_nrunnable;
496 } while ((cpupart = cpupart->cp_next) != cp_list_head);
499 /* Now count the per-CPU statistics. */
500 cp = cpu_list;
501 do {
502 uint_t cpu_nrunnable = cp->cpu_disp->disp_nrunnable;
504 nrunnable += cpu_nrunnable;
505 cpupart = cp->cpu_part;
506 cpupart->cp_nrunnable_cum += cpu_nrunnable;
507 if (one_sec) {
508 cpupart->cp_nrunnable += cpu_nrunnable;
510 * Update user, system, and idle cpu times.
512 cpupart->cp_nrunning++;
514 * w_io is used to update sysinfo.waiting during
515 * one_second processing below. Only gather w_io
516 * information when we walk the list of cpus if we're
517 * going to perform one_second processing.
519 w_io += CPU_STATS(cp, sys.iowait);
522 if (one_sec && (cp->cpu_flags & CPU_EXISTS)) {
523 int i, load, change;
524 hrtime_t intracct, intrused;
525 const hrtime_t maxnsec = 1000000000;
526 const int precision = 100;
529 * Estimate interrupt load on this cpu each second.
530 * Computes cpu_intrload as %utilization (0-99).
533 /* add up interrupt time from all micro states */
534 for (intracct = 0, i = 0; i < NCMSTATES; i++)
535 intracct += cp->cpu_intracct[i];
536 scalehrtime(&intracct);
538 /* compute nsec used in the past second */
539 intrused = intracct - cp->cpu_intrlast;
540 cp->cpu_intrlast = intracct;
542 /* limit the value for safety (and the first pass) */
543 if (intrused >= maxnsec)
544 intrused = maxnsec - 1;
546 /* calculate %time in interrupt */
547 load = (precision * intrused) / maxnsec;
548 ASSERT(load >= 0 && load < precision);
549 change = cp->cpu_intrload - load;
551 /* jump to new max, or decay the old max */
552 if (change < 0)
553 cp->cpu_intrload = load;
554 else if (change > 0)
555 cp->cpu_intrload -= (change + 3) / 4;
557 DTRACE_PROBE3(cpu_intrload,
558 cpu_t *, cp,
559 hrtime_t, intracct,
560 hrtime_t, intrused);
563 if (do_lgrp_load &&
564 (cp->cpu_flags & CPU_EXISTS)) {
566 * When updating the lgroup's load average,
567 * account for the thread running on the CPU.
568 * If the CPU is the current one, then we need
569 * to account for the underlying thread which
570 * got the clock interrupt not the thread that is
571 * handling the interrupt and caculating the load
572 * average
574 t = cp->cpu_thread;
575 if (CPU == cp)
576 t = t->t_intr;
579 * Account for the load average for this thread if
580 * it isn't the idle thread or it is on the interrupt
581 * stack and not the current CPU handling the clock
582 * interrupt
584 if ((t && t != cp->cpu_idle_thread) || (CPU != cp &&
585 CPU_ON_INTR(cp))) {
586 if (t->t_lpl == cp->cpu_lpl) {
587 /* local thread */
588 cpu_nrunnable++;
589 } else {
591 * This is a remote thread, charge it
592 * against its home lgroup. Note that
593 * we notice that a thread is remote
594 * only if it's currently executing.
595 * This is a reasonable approximation,
596 * since queued remote threads are rare.
597 * Note also that if we didn't charge
598 * it to its home lgroup, remote
599 * execution would often make a system
600 * appear balanced even though it was
601 * not, and thread placement/migration
602 * would often not be done correctly.
604 lgrp_loadavg(t->t_lpl,
605 LGRP_LOADAVG_IN_THREAD_MAX, 0);
608 lgrp_loadavg(cp->cpu_lpl,
609 cpu_nrunnable * LGRP_LOADAVG_IN_THREAD_MAX, 1);
611 } while ((cp = cp->cpu_next) != cpu_list);
613 clock_tick_schedule(one_sec);
616 * Check for a callout that needs be called from the clock
617 * thread to support the membership protocol in a clustered
618 * system. Copy the function pointer so that we can reset
619 * this to NULL if needed.
621 if ((funcp = cmm_clock_callout) != NULL)
622 (*funcp)();
624 if ((funcp = cpucaps_clock_callout) != NULL)
625 (*funcp)();
628 * Wakeup the cageout thread waiters once per second.
630 if (one_sec)
631 kcage_tick();
633 if (one_sec) {
635 int drift, absdrift;
636 timestruc_t tod;
637 int s;
640 * Beginning of precision-kernel code fragment executed
641 * every second.
643 * On rollover of the second the phase adjustment to be
644 * used for the next second is calculated. Also, the
645 * maximum error is increased by the tolerance. If the
646 * PPS frequency discipline code is present, the phase is
647 * increased to compensate for the CPU clock oscillator
648 * frequency error.
650 * On a 32-bit machine and given parameters in the timex.h
651 * header file, the maximum phase adjustment is +-512 ms
652 * and maximum frequency offset is (a tad less than)
653 * +-512 ppm. On a 64-bit machine, you shouldn't need to ask.
655 time_maxerror += time_tolerance / SCALE_USEC;
658 * Leap second processing. If in leap-insert state at
659 * the end of the day, the system clock is set back one
660 * second; if in leap-delete state, the system clock is
661 * set ahead one second. The microtime() routine or
662 * external clock driver will insure that reported time
663 * is always monotonic. The ugly divides should be
664 * replaced.
666 switch (time_state) {
668 case TIME_OK:
669 if (time_status & STA_INS)
670 time_state = TIME_INS;
671 else if (time_status & STA_DEL)
672 time_state = TIME_DEL;
673 break;
675 case TIME_INS:
676 if (hrestime.tv_sec % 86400 == 0) {
677 s = hr_clock_lock();
678 hrestime.tv_sec--;
679 hr_clock_unlock(s);
680 time_state = TIME_OOP;
682 break;
684 case TIME_DEL:
685 if ((hrestime.tv_sec + 1) % 86400 == 0) {
686 s = hr_clock_lock();
687 hrestime.tv_sec++;
688 hr_clock_unlock(s);
689 time_state = TIME_WAIT;
691 break;
693 case TIME_OOP:
694 time_state = TIME_WAIT;
695 break;
697 case TIME_WAIT:
698 if (!(time_status & (STA_INS | STA_DEL)))
699 time_state = TIME_OK;
700 default:
701 break;
705 * Compute the phase adjustment for the next second. In
706 * PLL mode, the offset is reduced by a fixed factor
707 * times the time constant. In FLL mode the offset is
708 * used directly. In either mode, the maximum phase
709 * adjustment for each second is clamped so as to spread
710 * the adjustment over not more than the number of
711 * seconds between updates.
713 if (time_offset == 0)
714 time_adj = 0;
715 else if (time_offset < 0) {
716 lltemp = -time_offset;
717 if (!(time_status & STA_FLL)) {
718 if ((1 << time_constant) >= SCALE_KG)
719 lltemp *= (1 << time_constant) /
720 SCALE_KG;
721 else
722 lltemp = (lltemp / SCALE_KG) >>
723 time_constant;
725 if (lltemp > (MAXPHASE / MINSEC) * SCALE_UPDATE)
726 lltemp = (MAXPHASE / MINSEC) * SCALE_UPDATE;
727 time_offset += lltemp;
728 time_adj = -(lltemp * SCALE_PHASE) / hz / SCALE_UPDATE;
729 } else {
730 lltemp = time_offset;
731 if (!(time_status & STA_FLL)) {
732 if ((1 << time_constant) >= SCALE_KG)
733 lltemp *= (1 << time_constant) /
734 SCALE_KG;
735 else
736 lltemp = (lltemp / SCALE_KG) >>
737 time_constant;
739 if (lltemp > (MAXPHASE / MINSEC) * SCALE_UPDATE)
740 lltemp = (MAXPHASE / MINSEC) * SCALE_UPDATE;
741 time_offset -= lltemp;
742 time_adj = (lltemp * SCALE_PHASE) / hz / SCALE_UPDATE;
746 * Compute the frequency estimate and additional phase
747 * adjustment due to frequency error for the next
748 * second. When the PPS signal is engaged, gnaw on the
749 * watchdog counter and update the frequency computed by
750 * the pll and the PPS signal.
752 pps_valid++;
753 if (pps_valid == PPS_VALID) {
754 pps_jitter = MAXTIME;
755 pps_stabil = MAXFREQ;
756 time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
757 STA_PPSWANDER | STA_PPSERROR);
759 lltemp = time_freq + pps_freq;
761 if (lltemp)
762 time_adj += (lltemp * SCALE_PHASE) / (SCALE_USEC * hz);
765 * End of precision kernel-code fragment
767 * The section below should be modified if we are planning
768 * to use NTP for synchronization.
770 * Note: the clock synchronization code now assumes
771 * the following:
772 * - if dosynctodr is 1, then compute the drift between
773 * the tod chip and software time and adjust one or
774 * the other depending on the circumstances
776 * - if dosynctodr is 0, then the tod chip is independent
777 * of the software clock and should not be adjusted,
778 * but allowed to free run. this allows NTP to sync.
779 * hrestime without any interference from the tod chip.
782 tod_validate_deferred = B_FALSE;
783 mutex_enter(&tod_lock);
784 tod = tod_get();
785 drift = tod.tv_sec - hrestime.tv_sec;
786 absdrift = (drift >= 0) ? drift : -drift;
787 if (tod_needsync || absdrift > 1) {
788 int s;
789 if (absdrift > 2) {
790 if (!tod_broken && tod_faulted == TOD_NOFAULT) {
791 s = hr_clock_lock();
792 hrestime = tod;
793 membar_enter(); /* hrestime visible */
794 timedelta = 0;
795 timechanged++;
796 tod_needsync = 0;
797 hr_clock_unlock(s);
798 callout_hrestime();
801 } else {
802 if (tod_needsync || !dosynctodr) {
803 gethrestime(&tod);
804 tod_set(tod);
805 s = hr_clock_lock();
806 if (timedelta == 0)
807 tod_needsync = 0;
808 hr_clock_unlock(s);
809 } else {
811 * If the drift is 2 seconds on the
812 * money, then the TOD is adjusting
813 * the clock; record that.
815 clock_adj_hist[adj_hist_entry++ %
816 CLOCK_ADJ_HIST_SIZE] = now;
817 s = hr_clock_lock();
818 timedelta = (int64_t)drift*NANOSEC;
819 hr_clock_unlock(s);
823 one_sec = 0;
824 time = gethrestime_sec(); /* for crusty old kmem readers */
825 mutex_exit(&tod_lock);
828 * Some drivers still depend on this... XXX
830 cv_broadcast(&lbolt_cv);
832 vminfo.freemem += freemem;
834 pgcnt_t maxswap, resv, free;
835 pgcnt_t avail =
836 MAX((spgcnt_t)(availrmem - swapfs_minfree), 0);
838 maxswap = k_anoninfo.ani_mem_resv +
839 k_anoninfo.ani_max +avail;
840 /* Update ani_free */
841 set_anoninfo();
842 free = k_anoninfo.ani_free + avail;
843 resv = k_anoninfo.ani_phys_resv +
844 k_anoninfo.ani_mem_resv;
846 vminfo.swap_resv += resv;
847 /* number of reserved and allocated pages */
848 #ifdef DEBUG
849 if (maxswap < free)
850 cmn_err(CE_WARN, "clock: maxswap < free");
851 if (maxswap < resv)
852 cmn_err(CE_WARN, "clock: maxswap < resv");
853 #endif
854 vminfo.swap_alloc += maxswap - free;
855 vminfo.swap_avail += maxswap - resv;
856 vminfo.swap_free += free;
858 vminfo.updates++;
859 if (nrunnable) {
860 sysinfo.runque += nrunnable;
861 sysinfo.runocc++;
863 if (nswapped) {
864 sysinfo.swpque += nswapped;
865 sysinfo.swpocc++;
867 sysinfo.waiting += w_io;
868 sysinfo.updates++;
871 * Wake up fsflush to write out DELWRI
872 * buffers, dirty pages and other cached
873 * administrative data, e.g. inodes.
875 if (--fsflushcnt <= 0) {
876 fsflushcnt = tune.t_fsflushr;
877 cv_signal(&fsflush_cv);
880 vmmeter();
881 calcloadavg(genloadavg(&loadavg), hp_avenrun);
882 for (i = 0; i < 3; i++)
884 * At the moment avenrun[] can only hold 31
885 * bits of load average as it is a signed
886 * int in the API. We need to ensure that
887 * hp_avenrun[i] >> (16 - FSHIFT) will not be
888 * too large. If it is, we put the largest value
889 * that we can use into avenrun[i]. This is
890 * kludgey, but about all we can do until we
891 * avenrun[] is declared as an array of uint64[]
893 if (hp_avenrun[i] < ((uint64_t)1<<(31+16-FSHIFT)))
894 avenrun[i] = (int32_t)(hp_avenrun[i] >>
895 (16 - FSHIFT));
896 else
897 avenrun[i] = 0x7fffffff;
899 cpupart = cp_list_head;
900 do {
901 calcloadavg(genloadavg(&cpupart->cp_loadavg),
902 cpupart->cp_hp_avenrun);
903 } while ((cpupart = cpupart->cp_next) != cp_list_head);
906 * Wake up the swapper thread if necessary.
908 if (runin ||
909 (runout && (avefree < desfree || wake_sched_sec))) {
910 t = &t0;
911 thread_lock(t);
912 if (t->t_state == TS_STOPPED) {
913 runin = runout = 0;
914 wake_sched_sec = 0;
915 t->t_whystop = 0;
916 t->t_whatstop = 0;
917 t->t_schedflag &= ~TS_ALLSTART;
918 THREAD_TRANSITION(t);
919 setfrontdq(t);
921 thread_unlock(t);
926 * Wake up the swapper if any high priority swapped-out threads
927 * became runable during the last tick.
929 if (wake_sched) {
930 t = &t0;
931 thread_lock(t);
932 if (t->t_state == TS_STOPPED) {
933 runin = runout = 0;
934 wake_sched = 0;
935 t->t_whystop = 0;
936 t->t_whatstop = 0;
937 t->t_schedflag &= ~TS_ALLSTART;
938 THREAD_TRANSITION(t);
939 setfrontdq(t);
941 thread_unlock(t);
945 void
946 clock_init(void)
948 cyc_handler_t clk_hdlr, timer_hdlr, lbolt_hdlr;
949 cyc_time_t clk_when, lbolt_when;
950 int i, sz;
951 intptr_t buf;
954 * Setup handler and timer for the clock cyclic.
956 clk_hdlr.cyh_func = (cyc_func_t)clock;
957 clk_hdlr.cyh_level = CY_LOCK_LEVEL;
958 clk_hdlr.cyh_arg = NULL;
960 clk_when.cyt_when = 0;
961 clk_when.cyt_interval = nsec_per_tick;
964 * cyclic_timer is dedicated to the ddi interface, which
965 * uses the same clock resolution as the system one.
967 timer_hdlr.cyh_func = (cyc_func_t)cyclic_timer;
968 timer_hdlr.cyh_level = CY_LOCK_LEVEL;
969 timer_hdlr.cyh_arg = NULL;
972 * The lbolt cyclic will be reprogramed to fire at a nsec_per_tick
973 * interval to satisfy performance needs of the DDI lbolt consumers.
974 * It is off by default.
976 lbolt_hdlr.cyh_func = (cyc_func_t)lbolt_cyclic;
977 lbolt_hdlr.cyh_level = CY_LOCK_LEVEL;
978 lbolt_hdlr.cyh_arg = NULL;
980 lbolt_when.cyt_interval = nsec_per_tick;
983 * Allocate cache line aligned space for the per CPU lbolt data and
984 * lbolt info structures, and initialize them with their default
985 * values. Note that these structures are also cache line sized.
987 sz = sizeof (lbolt_info_t) + CPU_CACHE_COHERENCE_SIZE;
988 buf = (intptr_t)kmem_zalloc(sz, KM_SLEEP);
989 lb_info = (lbolt_info_t *)P2ROUNDUP(buf, CPU_CACHE_COHERENCE_SIZE);
991 if (hz != HZ_DEFAULT)
992 lb_info->lbi_thresh_interval = LBOLT_THRESH_INTERVAL *
993 hz/HZ_DEFAULT;
994 else
995 lb_info->lbi_thresh_interval = LBOLT_THRESH_INTERVAL;
997 lb_info->lbi_thresh_calls = LBOLT_THRESH_CALLS;
999 sz = (sizeof (lbolt_cpu_t) * max_ncpus) + CPU_CACHE_COHERENCE_SIZE;
1000 buf = (intptr_t)kmem_zalloc(sz, KM_SLEEP);
1001 lb_cpu = (lbolt_cpu_t *)P2ROUNDUP(buf, CPU_CACHE_COHERENCE_SIZE);
1003 for (i = 0; i < max_ncpus; i++)
1004 lb_cpu[i].lbc_counter = lb_info->lbi_thresh_calls;
1007 * Install the softint used to switch between event and cyclic driven
1008 * lbolt. We use a soft interrupt to make sure the context of the
1009 * cyclic reprogram call is safe.
1011 lbolt_softint_add();
1014 * Since the hybrid lbolt implementation is based on a hardware counter
1015 * that is reset at every hardware reboot and that we'd like to have
1016 * the lbolt value starting at zero after both a hardware and a fast
1017 * reboot, we calculate the number of clock ticks the system's been up
1018 * and store it in the lbi_debug_time field of the lbolt info structure.
1019 * The value of this field will be subtracted from lbolt before
1020 * returning it.
1022 lb_info->lbi_internal = lb_info->lbi_debug_time =
1023 (gethrtime()/nsec_per_tick);
1026 * lbolt_hybrid points at lbolt_bootstrap until now. The LBOLT_* macros
1027 * and lbolt_debug_{enter,return} use this value as an indication that
1028 * the initializaion above hasn't been completed. Setting lbolt_hybrid
1029 * to either lbolt_{cyclic,event}_driven here signals those code paths
1030 * that the lbolt related structures can be used.
1032 if (lbolt_cyc_only) {
1033 lbolt_when.cyt_when = 0;
1034 lbolt_hybrid = lbolt_cyclic_driven;
1035 } else {
1036 lbolt_when.cyt_when = CY_INFINITY;
1037 lbolt_hybrid = lbolt_event_driven;
1041 * Grab cpu_lock and install all three cyclics.
1043 mutex_enter(&cpu_lock);
1045 clock_cyclic = cyclic_add(&clk_hdlr, &clk_when);
1046 ddi_timer_cyclic = cyclic_add(&timer_hdlr, &clk_when);
1047 lb_info->id.lbi_cyclic_id = cyclic_add(&lbolt_hdlr, &lbolt_when);
1049 mutex_exit(&cpu_lock);
1053 * Called before calcloadavg to get 10-sec moving loadavg together
1056 static int
1057 genloadavg(struct loadavg_s *avgs)
1059 int avg;
1060 int spos; /* starting position */
1061 int cpos; /* moving current position */
1062 int i;
1063 int slen;
1064 hrtime_t hr_avg;
1066 /* 10-second snapshot, calculate first positon */
1067 if (avgs->lg_len == 0) {
1068 return (0);
1070 slen = avgs->lg_len < S_MOVAVG_SZ ? avgs->lg_len : S_MOVAVG_SZ;
1072 spos = (avgs->lg_cur - 1) >= 0 ? avgs->lg_cur - 1 :
1073 S_LOADAVG_SZ + (avgs->lg_cur - 1);
1074 for (i = hr_avg = 0; i < slen; i++) {
1075 cpos = (spos - i) >= 0 ? spos - i : S_LOADAVG_SZ + (spos - i);
1076 hr_avg += avgs->lg_loads[cpos];
1079 hr_avg = hr_avg / slen;
1080 avg = hr_avg / (NANOSEC / LGRP_LOADAVG_IN_THREAD_MAX);
1082 return (avg);
1086 * Run every second from clock () to update the loadavg count available to the
1087 * system and cpu-partitions.
1089 * This works by sampling the previous usr, sys, wait time elapsed,
1090 * computing a delta, and adding that delta to the elapsed usr, sys,
1091 * wait increase.
1094 static void
1095 loadavg_update()
1097 cpu_t *cp;
1098 cpupart_t *cpupart;
1099 hrtime_t cpu_total;
1100 int prev;
1102 cp = cpu_list;
1103 loadavg.lg_total = 0;
1106 * first pass totals up per-cpu statistics for system and cpu
1107 * partitions
1110 do {
1111 struct loadavg_s *lavg;
1113 lavg = &cp->cpu_loadavg;
1115 cpu_total = cp->cpu_acct[CMS_USER] +
1116 cp->cpu_acct[CMS_SYSTEM] + cp->cpu_waitrq;
1117 /* compute delta against last total */
1118 scalehrtime(&cpu_total);
1119 prev = (lavg->lg_cur - 1) >= 0 ? lavg->lg_cur - 1 :
1120 S_LOADAVG_SZ + (lavg->lg_cur - 1);
1121 if (lavg->lg_loads[prev] <= 0) {
1122 lavg->lg_loads[lavg->lg_cur] = cpu_total;
1123 cpu_total = 0;
1124 } else {
1125 lavg->lg_loads[lavg->lg_cur] = cpu_total;
1126 cpu_total = cpu_total - lavg->lg_loads[prev];
1127 if (cpu_total < 0)
1128 cpu_total = 0;
1131 lavg->lg_cur = (lavg->lg_cur + 1) % S_LOADAVG_SZ;
1132 lavg->lg_len = (lavg->lg_len + 1) < S_LOADAVG_SZ ?
1133 lavg->lg_len + 1 : S_LOADAVG_SZ;
1135 loadavg.lg_total += cpu_total;
1136 cp->cpu_part->cp_loadavg.lg_total += cpu_total;
1138 } while ((cp = cp->cpu_next) != cpu_list);
1140 loadavg.lg_loads[loadavg.lg_cur] = loadavg.lg_total;
1141 loadavg.lg_cur = (loadavg.lg_cur + 1) % S_LOADAVG_SZ;
1142 loadavg.lg_len = (loadavg.lg_len + 1) < S_LOADAVG_SZ ?
1143 loadavg.lg_len + 1 : S_LOADAVG_SZ;
1145 * Second pass updates counts
1147 cpupart = cp_list_head;
1149 do {
1150 struct loadavg_s *lavg;
1152 lavg = &cpupart->cp_loadavg;
1153 lavg->lg_loads[lavg->lg_cur] = lavg->lg_total;
1154 lavg->lg_total = 0;
1155 lavg->lg_cur = (lavg->lg_cur + 1) % S_LOADAVG_SZ;
1156 lavg->lg_len = (lavg->lg_len + 1) < S_LOADAVG_SZ ?
1157 lavg->lg_len + 1 : S_LOADAVG_SZ;
1159 } while ((cpupart = cpupart->cp_next) != cp_list_head);
1164 * clock_update() - local clock update
1166 * This routine is called by ntp_adjtime() to update the local clock
1167 * phase and frequency. The implementation is of an
1168 * adaptive-parameter, hybrid phase/frequency-lock loop (PLL/FLL). The
1169 * routine computes new time and frequency offset estimates for each
1170 * call. The PPS signal itself determines the new time offset,
1171 * instead of the calling argument. Presumably, calls to
1172 * ntp_adjtime() occur only when the caller believes the local clock
1173 * is valid within some bound (+-128 ms with NTP). If the caller's
1174 * time is far different than the PPS time, an argument will ensue,
1175 * and it's not clear who will lose.
1177 * For uncompensated quartz crystal oscillatores and nominal update
1178 * intervals less than 1024 s, operation should be in phase-lock mode
1179 * (STA_FLL = 0), where the loop is disciplined to phase. For update
1180 * intervals greater than this, operation should be in frequency-lock
1181 * mode (STA_FLL = 1), where the loop is disciplined to frequency.
1183 * Note: mutex(&tod_lock) is in effect.
1185 void
1186 clock_update(int offset)
1188 int ltemp, mtemp, s;
1190 ASSERT(MUTEX_HELD(&tod_lock));
1192 if (!(time_status & STA_PLL) && !(time_status & STA_PPSTIME))
1193 return;
1194 ltemp = offset;
1195 if ((time_status & STA_PPSTIME) && (time_status & STA_PPSSIGNAL))
1196 ltemp = pps_offset;
1199 * Scale the phase adjustment and clamp to the operating range.
1201 if (ltemp > MAXPHASE)
1202 time_offset = MAXPHASE * SCALE_UPDATE;
1203 else if (ltemp < -MAXPHASE)
1204 time_offset = -(MAXPHASE * SCALE_UPDATE);
1205 else
1206 time_offset = ltemp * SCALE_UPDATE;
1209 * Select whether the frequency is to be controlled and in which
1210 * mode (PLL or FLL). Clamp to the operating range. Ugly
1211 * multiply/divide should be replaced someday.
1213 if (time_status & STA_FREQHOLD || time_reftime == 0)
1214 time_reftime = hrestime.tv_sec;
1216 mtemp = hrestime.tv_sec - time_reftime;
1217 time_reftime = hrestime.tv_sec;
1219 if (time_status & STA_FLL) {
1220 if (mtemp >= MINSEC) {
1221 ltemp = ((time_offset / mtemp) * (SCALE_USEC /
1222 SCALE_UPDATE));
1223 if (ltemp)
1224 time_freq += ltemp / SCALE_KH;
1226 } else {
1227 if (mtemp < MAXSEC) {
1228 ltemp *= mtemp;
1229 if (ltemp)
1230 time_freq += (int)(((int64_t)ltemp *
1231 SCALE_USEC) / SCALE_KF)
1232 / (1 << (time_constant * 2));
1235 if (time_freq > time_tolerance)
1236 time_freq = time_tolerance;
1237 else if (time_freq < -time_tolerance)
1238 time_freq = -time_tolerance;
1240 s = hr_clock_lock();
1241 tod_needsync = 1;
1242 hr_clock_unlock(s);
1246 * ddi_hardpps() - discipline CPU clock oscillator to external PPS signal
1248 * This routine is called at each PPS interrupt in order to discipline
1249 * the CPU clock oscillator to the PPS signal. It measures the PPS phase
1250 * and leaves it in a handy spot for the clock() routine. It
1251 * integrates successive PPS phase differences and calculates the
1252 * frequency offset. This is used in clock() to discipline the CPU
1253 * clock oscillator so that intrinsic frequency error is cancelled out.
1254 * The code requires the caller to capture the time and hardware counter
1255 * value at the on-time PPS signal transition.
1257 * Note that, on some Unix systems, this routine runs at an interrupt
1258 * priority level higher than the timer interrupt routine clock().
1259 * Therefore, the variables used are distinct from the clock()
1260 * variables, except for certain exceptions: The PPS frequency pps_freq
1261 * and phase pps_offset variables are determined by this routine and
1262 * updated atomically. The time_tolerance variable can be considered a
1263 * constant, since it is infrequently changed, and then only when the
1264 * PPS signal is disabled. The watchdog counter pps_valid is updated
1265 * once per second by clock() and is atomically cleared in this
1266 * routine.
1268 * tvp is the time of the last tick; usec is a microsecond count since the
1269 * last tick.
1271 * Note: In Solaris systems, the tick value is actually given by
1272 * usec_per_tick. This is called from the serial driver cdintr(),
1273 * or equivalent, at a high PIL. Because the kernel keeps a
1274 * highresolution time, the following code can accept either
1275 * the traditional argument pair, or the current highres timestamp
1276 * in tvp and zero in usec.
1278 void
1279 ddi_hardpps(struct timeval *tvp, int usec)
1281 int u_usec, v_usec, bigtick;
1282 time_t cal_sec;
1283 int cal_usec;
1286 * An occasional glitch can be produced when the PPS interrupt
1287 * occurs in the clock() routine before the time variable is
1288 * updated. Here the offset is discarded when the difference
1289 * between it and the last one is greater than tick/2, but not
1290 * if the interval since the first discard exceeds 30 s.
1292 time_status |= STA_PPSSIGNAL;
1293 time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
1294 pps_valid = 0;
1295 u_usec = -tvp->tv_usec;
1296 if (u_usec < -(MICROSEC/2))
1297 u_usec += MICROSEC;
1298 v_usec = pps_offset - u_usec;
1299 if (v_usec < 0)
1300 v_usec = -v_usec;
1301 if (v_usec > (usec_per_tick >> 1)) {
1302 if (pps_glitch > MAXGLITCH) {
1303 pps_glitch = 0;
1304 pps_tf[2] = u_usec;
1305 pps_tf[1] = u_usec;
1306 } else {
1307 pps_glitch++;
1308 u_usec = pps_offset;
1310 } else
1311 pps_glitch = 0;
1314 * A three-stage median filter is used to help deglitch the pps
1315 * time. The median sample becomes the time offset estimate; the
1316 * difference between the other two samples becomes the time
1317 * dispersion (jitter) estimate.
1319 pps_tf[2] = pps_tf[1];
1320 pps_tf[1] = pps_tf[0];
1321 pps_tf[0] = u_usec;
1322 if (pps_tf[0] > pps_tf[1]) {
1323 if (pps_tf[1] > pps_tf[2]) {
1324 pps_offset = pps_tf[1]; /* 0 1 2 */
1325 v_usec = pps_tf[0] - pps_tf[2];
1326 } else if (pps_tf[2] > pps_tf[0]) {
1327 pps_offset = pps_tf[0]; /* 2 0 1 */
1328 v_usec = pps_tf[2] - pps_tf[1];
1329 } else {
1330 pps_offset = pps_tf[2]; /* 0 2 1 */
1331 v_usec = pps_tf[0] - pps_tf[1];
1333 } else {
1334 if (pps_tf[1] < pps_tf[2]) {
1335 pps_offset = pps_tf[1]; /* 2 1 0 */
1336 v_usec = pps_tf[2] - pps_tf[0];
1337 } else if (pps_tf[2] < pps_tf[0]) {
1338 pps_offset = pps_tf[0]; /* 1 0 2 */
1339 v_usec = pps_tf[1] - pps_tf[2];
1340 } else {
1341 pps_offset = pps_tf[2]; /* 1 2 0 */
1342 v_usec = pps_tf[1] - pps_tf[0];
1345 if (v_usec > MAXTIME)
1346 pps_jitcnt++;
1347 v_usec = (v_usec << PPS_AVG) - pps_jitter;
1348 pps_jitter += v_usec / (1 << PPS_AVG);
1349 if (pps_jitter > (MAXTIME >> 1))
1350 time_status |= STA_PPSJITTER;
1353 * During the calibration interval adjust the starting time when
1354 * the tick overflows. At the end of the interval compute the
1355 * duration of the interval and the difference of the hardware
1356 * counters at the beginning and end of the interval. This code
1357 * is deliciously complicated by the fact valid differences may
1358 * exceed the value of tick when using long calibration
1359 * intervals and small ticks. Note that the counter can be
1360 * greater than tick if caught at just the wrong instant, but
1361 * the values returned and used here are correct.
1363 bigtick = (int)usec_per_tick * SCALE_USEC;
1364 pps_usec -= pps_freq;
1365 if (pps_usec >= bigtick)
1366 pps_usec -= bigtick;
1367 if (pps_usec < 0)
1368 pps_usec += bigtick;
1369 pps_time.tv_sec++;
1370 pps_count++;
1371 if (pps_count < (1 << pps_shift))
1372 return;
1373 pps_count = 0;
1374 pps_calcnt++;
1375 u_usec = usec * SCALE_USEC;
1376 v_usec = pps_usec - u_usec;
1377 if (v_usec >= bigtick >> 1)
1378 v_usec -= bigtick;
1379 if (v_usec < -(bigtick >> 1))
1380 v_usec += bigtick;
1381 if (v_usec < 0)
1382 v_usec = -(-v_usec >> pps_shift);
1383 else
1384 v_usec = v_usec >> pps_shift;
1385 pps_usec = u_usec;
1386 cal_sec = tvp->tv_sec;
1387 cal_usec = tvp->tv_usec;
1388 cal_sec -= pps_time.tv_sec;
1389 cal_usec -= pps_time.tv_usec;
1390 if (cal_usec < 0) {
1391 cal_usec += MICROSEC;
1392 cal_sec--;
1394 pps_time = *tvp;
1397 * Check for lost interrupts, noise, excessive jitter and
1398 * excessive frequency error. The number of timer ticks during
1399 * the interval may vary +-1 tick. Add to this a margin of one
1400 * tick for the PPS signal jitter and maximum frequency
1401 * deviation. If the limits are exceeded, the calibration
1402 * interval is reset to the minimum and we start over.
1404 u_usec = (int)usec_per_tick << 1;
1405 if (!((cal_sec == -1 && cal_usec > (MICROSEC - u_usec)) ||
1406 (cal_sec == 0 && cal_usec < u_usec)) ||
1407 v_usec > time_tolerance || v_usec < -time_tolerance) {
1408 pps_errcnt++;
1409 pps_shift = PPS_SHIFT;
1410 pps_intcnt = 0;
1411 time_status |= STA_PPSERROR;
1412 return;
1416 * A three-stage median filter is used to help deglitch the pps
1417 * frequency. The median sample becomes the frequency offset
1418 * estimate; the difference between the other two samples
1419 * becomes the frequency dispersion (stability) estimate.
1421 pps_ff[2] = pps_ff[1];
1422 pps_ff[1] = pps_ff[0];
1423 pps_ff[0] = v_usec;
1424 if (pps_ff[0] > pps_ff[1]) {
1425 if (pps_ff[1] > pps_ff[2]) {
1426 u_usec = pps_ff[1]; /* 0 1 2 */
1427 v_usec = pps_ff[0] - pps_ff[2];
1428 } else if (pps_ff[2] > pps_ff[0]) {
1429 u_usec = pps_ff[0]; /* 2 0 1 */
1430 v_usec = pps_ff[2] - pps_ff[1];
1431 } else {
1432 u_usec = pps_ff[2]; /* 0 2 1 */
1433 v_usec = pps_ff[0] - pps_ff[1];
1435 } else {
1436 if (pps_ff[1] < pps_ff[2]) {
1437 u_usec = pps_ff[1]; /* 2 1 0 */
1438 v_usec = pps_ff[2] - pps_ff[0];
1439 } else if (pps_ff[2] < pps_ff[0]) {
1440 u_usec = pps_ff[0]; /* 1 0 2 */
1441 v_usec = pps_ff[1] - pps_ff[2];
1442 } else {
1443 u_usec = pps_ff[2]; /* 1 2 0 */
1444 v_usec = pps_ff[1] - pps_ff[0];
1449 * Here the frequency dispersion (stability) is updated. If it
1450 * is less than one-fourth the maximum (MAXFREQ), the frequency
1451 * offset is updated as well, but clamped to the tolerance. It
1452 * will be processed later by the clock() routine.
1454 v_usec = (v_usec >> 1) - pps_stabil;
1455 if (v_usec < 0)
1456 pps_stabil -= -v_usec >> PPS_AVG;
1457 else
1458 pps_stabil += v_usec >> PPS_AVG;
1459 if (pps_stabil > MAXFREQ >> 2) {
1460 pps_stbcnt++;
1461 time_status |= STA_PPSWANDER;
1462 return;
1464 if (time_status & STA_PPSFREQ) {
1465 if (u_usec < 0) {
1466 pps_freq -= -u_usec >> PPS_AVG;
1467 if (pps_freq < -time_tolerance)
1468 pps_freq = -time_tolerance;
1469 u_usec = -u_usec;
1470 } else {
1471 pps_freq += u_usec >> PPS_AVG;
1472 if (pps_freq > time_tolerance)
1473 pps_freq = time_tolerance;
1478 * Here the calibration interval is adjusted. If the maximum
1479 * time difference is greater than tick / 4, reduce the interval
1480 * by half. If this is not the case for four consecutive
1481 * intervals, double the interval.
1483 if (u_usec << pps_shift > bigtick >> 2) {
1484 pps_intcnt = 0;
1485 if (pps_shift > PPS_SHIFT)
1486 pps_shift--;
1487 } else if (pps_intcnt >= 4) {
1488 pps_intcnt = 0;
1489 if (pps_shift < PPS_SHIFTMAX)
1490 pps_shift++;
1491 } else
1492 pps_intcnt++;
1495 * If recovering from kmdb, then make sure the tod chip gets resynced.
1496 * If we took an early exit above, then we don't yet have a stable
1497 * calibration signal to lock onto, so don't mark the tod for sync
1498 * until we get all the way here.
1501 int s = hr_clock_lock();
1503 tod_needsync = 1;
1504 hr_clock_unlock(s);
1509 * Handle clock tick processing for a thread.
1510 * Check for timer action, enforce CPU rlimit, do profiling etc.
1512 void
1513 clock_tick(kthread_t *t, int pending)
1515 struct proc *pp;
1516 klwp_id_t lwp;
1517 struct as *as;
1518 clock_t ticks;
1519 int poke = 0; /* notify another CPU */
1520 int user_mode;
1521 size_t rss;
1522 int i, total_usec, usec;
1523 rctl_qty_t secs;
1525 ASSERT(pending > 0);
1527 /* Must be operating on a lwp/thread */
1528 if ((lwp = ttolwp(t)) == NULL) {
1529 panic("clock_tick: no lwp");
1530 /*NOTREACHED*/
1533 for (i = 0; i < pending; i++) {
1534 CL_TICK(t); /* Class specific tick processing */
1535 DTRACE_SCHED1(tick, kthread_t *, t);
1538 pp = ttoproc(t);
1540 /* pp->p_lock makes sure that the thread does not exit */
1541 ASSERT(MUTEX_HELD(&pp->p_lock));
1543 user_mode = (lwp->lwp_state == LWP_USER);
1545 ticks = (pp->p_utime + pp->p_stime) % hz;
1547 * Update process times. Should use high res clock and state
1548 * changes instead of statistical sampling method. XXX
1550 if (user_mode) {
1551 pp->p_utime += pending;
1552 } else {
1553 pp->p_stime += pending;
1556 pp->p_ttime += pending;
1557 as = pp->p_as;
1560 * Update user profiling statistics. Get the pc from the
1561 * lwp when the AST happens.
1563 if (pp->p_prof.pr_scale) {
1564 atomic_add_32(&lwp->lwp_oweupc, (int32_t)pending);
1565 if (user_mode) {
1566 poke = 1;
1567 aston(t);
1572 * If CPU was in user state, process lwp-virtual time
1573 * interval timer. The value passed to itimerdecr() has to be
1574 * in microseconds and has to be less than one second. Hence
1575 * this loop.
1577 total_usec = usec_per_tick * pending;
1578 while (total_usec > 0) {
1579 usec = MIN(total_usec, (MICROSEC - 1));
1580 if (user_mode &&
1581 timerisset(&lwp->lwp_timer[ITIMER_VIRTUAL].it_value) &&
1582 itimerdecr(&lwp->lwp_timer[ITIMER_VIRTUAL], usec) == 0) {
1583 poke = 1;
1584 sigtoproc(pp, t, SIGVTALRM);
1586 total_usec -= usec;
1590 * If CPU was in user state, process lwp-profile
1591 * interval timer.
1593 total_usec = usec_per_tick * pending;
1594 while (total_usec > 0) {
1595 usec = MIN(total_usec, (MICROSEC - 1));
1596 if (timerisset(&lwp->lwp_timer[ITIMER_PROF].it_value) &&
1597 itimerdecr(&lwp->lwp_timer[ITIMER_PROF], usec) == 0) {
1598 poke = 1;
1599 sigtoproc(pp, t, SIGPROF);
1601 total_usec -= usec;
1605 * Enforce CPU resource controls:
1606 * (a) process.max-cpu-time resource control
1608 * Perform the check only if we have accumulated more a second.
1610 if ((ticks + pending) >= hz) {
1611 (void) rctl_test(rctlproc_legacy[RLIMIT_CPU], pp->p_rctls, pp,
1612 (pp->p_utime + pp->p_stime)/hz, RCA_UNSAFE_SIGINFO);
1616 * (b) task.max-cpu-time resource control
1618 * If we have accumulated enough ticks, increment the task CPU
1619 * time usage and test for the resource limit. This minimizes the
1620 * number of calls to the rct_test(). The task CPU time mutex
1621 * is highly contentious as many processes can be sharing a task.
1623 if (pp->p_ttime >= clock_tick_proc_max) {
1624 secs = task_cpu_time_incr(pp->p_task, pp->p_ttime);
1625 pp->p_ttime = 0;
1626 if (secs) {
1627 (void) rctl_test(rc_task_cpu_time, pp->p_task->tk_rctls,
1628 pp, secs, RCA_UNSAFE_SIGINFO);
1633 * Update memory usage for the currently running process.
1635 rss = rm_asrss(as);
1636 PTOU(pp)->u_mem += rss;
1637 if (rss > PTOU(pp)->u_mem_max)
1638 PTOU(pp)->u_mem_max = rss;
1641 * Notify the CPU the thread is running on.
1643 if (poke && t->t_cpu != CPU)
1644 poke_cpu(t->t_cpu->cpu_id);
1647 void
1648 profil_tick(uintptr_t upc)
1650 int ticks;
1651 proc_t *p = ttoproc(curthread);
1652 klwp_t *lwp = ttolwp(curthread);
1653 struct prof *pr = &p->p_prof;
1655 do {
1656 ticks = lwp->lwp_oweupc;
1657 } while (cas32(&lwp->lwp_oweupc, ticks, 0) != ticks);
1659 mutex_enter(&p->p_pflock);
1660 if (pr->pr_scale >= 2 && upc >= pr->pr_off) {
1662 * Old-style profiling
1664 uint16_t *slot = pr->pr_base;
1665 uint16_t old, new;
1666 if (pr->pr_scale != 2) {
1667 uintptr_t delta = upc - pr->pr_off;
1668 uintptr_t byteoff = ((delta >> 16) * pr->pr_scale) +
1669 (((delta & 0xffff) * pr->pr_scale) >> 16);
1670 if (byteoff >= (uintptr_t)pr->pr_size) {
1671 mutex_exit(&p->p_pflock);
1672 return;
1674 slot += byteoff / sizeof (uint16_t);
1676 if (fuword16(slot, &old) < 0 ||
1677 (new = old + ticks) > SHRT_MAX ||
1678 suword16(slot, new) < 0) {
1679 pr->pr_scale = 0;
1681 } else if (pr->pr_scale == 1) {
1683 * PC Sampling
1685 model_t model = lwp_getdatamodel(lwp);
1686 int result;
1687 #ifdef __lint
1688 model = model;
1689 #endif
1690 while (ticks-- > 0) {
1691 if (pr->pr_samples == pr->pr_size) {
1692 /* buffer full, turn off sampling */
1693 pr->pr_scale = 0;
1694 break;
1696 switch (SIZEOF_PTR(model)) {
1697 case sizeof (uint32_t):
1698 result = suword32(pr->pr_base, (uint32_t)upc);
1699 break;
1700 #ifdef _LP64
1701 case sizeof (uint64_t):
1702 result = suword64(pr->pr_base, (uint64_t)upc);
1703 break;
1704 #endif
1705 default:
1706 cmn_err(CE_WARN, "profil_tick: unexpected "
1707 "data model");
1708 result = -1;
1709 break;
1711 if (result != 0) {
1712 pr->pr_scale = 0;
1713 break;
1715 pr->pr_base = (caddr_t)pr->pr_base + SIZEOF_PTR(model);
1716 pr->pr_samples++;
1719 mutex_exit(&p->p_pflock);
1722 static void
1723 delay_wakeup(void *arg)
1725 kthread_t *t = arg;
1727 mutex_enter(&t->t_delay_lock);
1728 cv_signal(&t->t_delay_cv);
1729 mutex_exit(&t->t_delay_lock);
1733 * The delay(9F) man page indicates that it can only be called from user or
1734 * kernel context - detect and diagnose bad calls. The following macro will
1735 * produce a limited number of messages identifying bad callers. This is done
1736 * in a macro so that caller() is meaningful. When a bad caller is identified,
1737 * switching to 'drv_usecwait(TICK_TO_USEC(ticks));' may be appropriate.
1739 #define DELAY_CONTEXT_CHECK() { \
1740 uint32_t m; \
1741 char *f; \
1742 ulong_t off; \
1744 m = delay_from_interrupt_msg; \
1745 if (delay_from_interrupt_diagnose && servicing_interrupt() && \
1746 !panicstr && !devinfo_freeze && \
1747 atomic_cas_32(&delay_from_interrupt_msg, m ? m : 1, m-1)) { \
1748 f = modgetsymname((uintptr_t)caller(), &off); \
1749 cmn_err(CE_WARN, "delay(9F) called from " \
1750 "interrupt context: %s`%s", \
1751 mod_containing_pc(caller()), f ? f : "..."); \
1756 * delay_common: common delay code.
1758 static void
1759 delay_common(clock_t ticks)
1761 kthread_t *t = curthread;
1762 clock_t deadline;
1763 clock_t timeleft;
1764 callout_id_t id;
1766 /* If timeouts aren't running all we can do is spin. */
1767 if (panicstr || devinfo_freeze) {
1768 /* Convert delay(9F) call into drv_usecwait(9F) call. */
1769 if (ticks > 0)
1770 drv_usecwait(TICK_TO_USEC(ticks));
1771 return;
1774 deadline = ddi_get_lbolt() + ticks;
1775 while ((timeleft = deadline - ddi_get_lbolt()) > 0) {
1776 mutex_enter(&t->t_delay_lock);
1777 id = timeout_default(delay_wakeup, t, timeleft);
1778 cv_wait(&t->t_delay_cv, &t->t_delay_lock);
1779 mutex_exit(&t->t_delay_lock);
1780 (void) untimeout_default(id, 0);
1785 * Delay specified number of clock ticks.
1787 void
1788 delay(clock_t ticks)
1790 DELAY_CONTEXT_CHECK();
1792 delay_common(ticks);
1796 * Delay a random number of clock ticks between 1 and ticks.
1798 void
1799 delay_random(clock_t ticks)
1801 int r;
1803 DELAY_CONTEXT_CHECK();
1805 (void) random_get_pseudo_bytes((void *)&r, sizeof (r));
1806 if (ticks == 0)
1807 ticks = 1;
1808 ticks = (r % ticks) + 1;
1809 delay_common(ticks);
1813 * Like delay, but interruptible by a signal.
1816 delay_sig(clock_t ticks)
1818 kthread_t *t = curthread;
1819 clock_t deadline;
1820 clock_t rc;
1822 /* If timeouts aren't running all we can do is spin. */
1823 if (panicstr || devinfo_freeze) {
1824 if (ticks > 0)
1825 drv_usecwait(TICK_TO_USEC(ticks));
1826 return (0);
1829 deadline = ddi_get_lbolt() + ticks;
1830 mutex_enter(&t->t_delay_lock);
1831 do {
1832 rc = cv_timedwait_sig(&t->t_delay_cv,
1833 &t->t_delay_lock, deadline);
1834 /* loop until past deadline or signaled */
1835 } while (rc > 0);
1836 mutex_exit(&t->t_delay_lock);
1837 if (rc == 0)
1838 return (EINTR);
1839 return (0);
1843 #define SECONDS_PER_DAY 86400
1846 * Initialize the system time based on the TOD chip. approx is used as
1847 * an approximation of time (e.g. from the filesystem) in the event that
1848 * the TOD chip has been cleared or is unresponsive. An approx of -1
1849 * means the filesystem doesn't keep time.
1851 void
1852 clkset(time_t approx)
1854 timestruc_t ts;
1855 int spl;
1856 int set_clock = 0;
1858 mutex_enter(&tod_lock);
1859 ts = tod_get();
1861 if (ts.tv_sec > 365 * SECONDS_PER_DAY) {
1863 * If the TOD chip is reporting some time after 1971,
1864 * then it probably didn't lose power or become otherwise
1865 * cleared in the recent past; check to assure that
1866 * the time coming from the filesystem isn't in the future
1867 * according to the TOD chip.
1869 if (approx != -1 && approx > ts.tv_sec) {
1870 cmn_err(CE_WARN, "Last shutdown is later "
1871 "than time on time-of-day chip; check date.");
1873 } else {
1875 * If the TOD chip isn't giving correct time, set it to the
1876 * greater of i) approx and ii) 1987. That way if approx
1877 * is negative or is earlier than 1987, we set the clock
1878 * back to a time when Oliver North, ALF and Dire Straits
1879 * were all on the collective brain: 1987.
1881 timestruc_t tmp;
1882 time_t diagnose_date = (1987 - 1970) * 365 * SECONDS_PER_DAY;
1883 ts.tv_sec = (approx > diagnose_date ? approx : diagnose_date);
1884 ts.tv_nsec = 0;
1887 * Attempt to write the new time to the TOD chip. Set spl high
1888 * to avoid getting preempted between the tod_set and tod_get.
1890 spl = splhi();
1891 tod_set(ts);
1892 tmp = tod_get();
1893 splx(spl);
1895 if (tmp.tv_sec != ts.tv_sec && tmp.tv_sec != ts.tv_sec + 1) {
1896 tod_broken = 1;
1897 dosynctodr = 0;
1898 cmn_err(CE_WARN, "Time-of-day chip unresponsive.");
1899 } else {
1900 cmn_err(CE_WARN, "Time-of-day chip had "
1901 "incorrect date; check and reset.");
1903 set_clock = 1;
1906 if (!boot_time) {
1907 boot_time = ts.tv_sec;
1908 set_clock = 1;
1911 if (set_clock)
1912 set_hrestime(&ts);
1914 mutex_exit(&tod_lock);
1917 int timechanged; /* for testing if the system time has been reset */
1919 void
1920 set_hrestime(timestruc_t *ts)
1922 int spl = hr_clock_lock();
1923 hrestime = *ts;
1924 membar_enter(); /* hrestime must be visible before timechanged++ */
1925 timedelta = 0;
1926 timechanged++;
1927 hr_clock_unlock(spl);
1928 callout_hrestime();
1931 static uint_t deadman_seconds;
1932 static uint32_t deadman_panics;
1933 static int deadman_enabled = 0;
1934 static int deadman_panic_timers = 1;
1936 static void
1937 deadman(void)
1939 if (panicstr) {
1941 * During panic, other CPUs besides the panic
1942 * master continue to handle cyclics and some other
1943 * interrupts. The code below is intended to be
1944 * single threaded, so any CPU other than the master
1945 * must keep out.
1947 if (CPU->cpu_id != panic_cpu.cpu_id)
1948 return;
1950 if (!deadman_panic_timers)
1951 return; /* allow all timers to be manually disabled */
1954 * If we are generating a crash dump or syncing filesystems and
1955 * the corresponding timer is set, decrement it and re-enter
1956 * the panic code to abort it and advance to the next state.
1957 * The panic states and triggers are explained in panic.c.
1959 if (panic_dump) {
1960 if (dump_timeleft && (--dump_timeleft == 0)) {
1961 panic("panic dump timeout");
1962 /*NOTREACHED*/
1964 } else if (panic_sync) {
1965 if (sync_timeleft && (--sync_timeleft == 0)) {
1966 panic("panic sync timeout");
1967 /*NOTREACHED*/
1971 return;
1974 if (deadman_counter != CPU->cpu_deadman_counter) {
1975 CPU->cpu_deadman_counter = deadman_counter;
1976 CPU->cpu_deadman_countdown = deadman_seconds;
1977 return;
1980 if (--CPU->cpu_deadman_countdown > 0)
1981 return;
1984 * Regardless of whether or not we actually bring the system down,
1985 * bump the deadman_panics variable.
1987 * N.B. deadman_panics is incremented once for each CPU that
1988 * passes through here. It's expected that all the CPUs will
1989 * detect this condition within one second of each other, so
1990 * when deadman_enabled is off, deadman_panics will
1991 * typically be a multiple of the total number of CPUs in
1992 * the system.
1994 atomic_add_32(&deadman_panics, 1);
1996 if (!deadman_enabled) {
1997 CPU->cpu_deadman_countdown = deadman_seconds;
1998 return;
2002 * If we're here, we want to bring the system down.
2004 panic("deadman: timed out after %d seconds of clock "
2005 "inactivity", deadman_seconds);
2006 /*NOTREACHED*/
2009 /*ARGSUSED*/
2010 static void
2011 deadman_online(void *arg, cpu_t *cpu, cyc_handler_t *hdlr, cyc_time_t *when)
2013 cpu->cpu_deadman_counter = 0;
2014 cpu->cpu_deadman_countdown = deadman_seconds;
2016 hdlr->cyh_func = (cyc_func_t)deadman;
2017 hdlr->cyh_level = CY_HIGH_LEVEL;
2018 hdlr->cyh_arg = NULL;
2021 * Stagger the CPUs so that they don't all run deadman() at
2022 * the same time. Simplest reason to do this is to make it
2023 * more likely that only one CPU will panic in case of a
2024 * timeout. This is (strictly speaking) an aesthetic, not a
2025 * technical consideration.
2027 when->cyt_when = cpu->cpu_id * (NANOSEC / NCPU);
2028 when->cyt_interval = NANOSEC;
2032 void
2033 deadman_init(void)
2035 cyc_omni_handler_t hdlr;
2037 if (deadman_seconds == 0)
2038 deadman_seconds = snoop_interval / MICROSEC;
2040 if (snooping)
2041 deadman_enabled = 1;
2043 hdlr.cyo_online = deadman_online;
2044 hdlr.cyo_offline = NULL;
2045 hdlr.cyo_arg = NULL;
2047 mutex_enter(&cpu_lock);
2048 deadman_cyclic = cyclic_add_omni(&hdlr);
2049 mutex_exit(&cpu_lock);
2053 * tod_fault() is for updating tod validate mechanism state:
2054 * (1) TOD_NOFAULT: for resetting the state to 'normal'.
2055 * currently used for debugging only
2056 * (2) The following four cases detected by tod validate mechanism:
2057 * TOD_REVERSED: current tod value is less than previous value.
2058 * TOD_STALLED: current tod value hasn't advanced.
2059 * TOD_JUMPED: current tod value advanced too far from previous value.
2060 * TOD_RATECHANGED: the ratio between average tod delta and
2061 * average tick delta has changed.
2062 * (3) TOD_RDONLY: when the TOD clock is not writeable e.g. because it is
2063 * a virtual TOD provided by a hypervisor.
2065 enum tod_fault_type
2066 tod_fault(enum tod_fault_type ftype, int off)
2068 ASSERT(MUTEX_HELD(&tod_lock));
2070 if (tod_faulted != ftype) {
2071 switch (ftype) {
2072 case TOD_NOFAULT:
2073 plat_tod_fault(TOD_NOFAULT);
2074 cmn_err(CE_NOTE, "Restarted tracking "
2075 "Time of Day clock.");
2076 tod_faulted = ftype;
2077 break;
2078 case TOD_REVERSED:
2079 case TOD_JUMPED:
2080 if (tod_faulted == TOD_NOFAULT) {
2081 plat_tod_fault(ftype);
2082 cmn_err(CE_WARN, "Time of Day clock error: "
2083 "reason [%s by 0x%x]. -- "
2084 " Stopped tracking Time Of Day clock.",
2085 tod_fault_table[ftype], off);
2086 tod_faulted = ftype;
2088 break;
2089 case TOD_STALLED:
2090 case TOD_RATECHANGED:
2091 if (tod_faulted == TOD_NOFAULT) {
2092 plat_tod_fault(ftype);
2093 cmn_err(CE_WARN, "Time of Day clock error: "
2094 "reason [%s]. -- "
2095 " Stopped tracking Time Of Day clock.",
2096 tod_fault_table[ftype]);
2097 tod_faulted = ftype;
2099 break;
2100 case TOD_RDONLY:
2101 if (tod_faulted == TOD_NOFAULT) {
2102 plat_tod_fault(ftype);
2103 cmn_err(CE_NOTE, "!Time of Day clock is "
2104 "Read-Only; set of Date/Time will not "
2105 "persist across reboot.");
2106 tod_faulted = ftype;
2108 break;
2109 default:
2110 break;
2113 return (tod_faulted);
2117 * Two functions that allow tod_status_flag to be manipulated by functions
2118 * external to this file.
2121 void
2122 tod_status_set(int tod_flag)
2124 tod_status_flag |= tod_flag;
2127 void
2128 tod_status_clear(int tod_flag)
2130 tod_status_flag &= ~tod_flag;
2134 * Record a timestamp and the value passed to tod_set(). The next call to
2135 * tod_validate() can use these values, prev_set_tick and prev_set_tod,
2136 * when checking the timestruc_t returned by tod_get(). Ordinarily,
2137 * tod_validate() will use prev_tick and prev_tod for this task but these
2138 * become obsolete, and will be re-assigned with the prev_set_* values,
2139 * in the case when the TOD is re-written.
2141 void
2142 tod_set_prev(timestruc_t ts)
2144 if ((tod_validate_enable == 0) || (tod_faulted != TOD_NOFAULT) ||
2145 tod_validate_deferred) {
2146 return;
2148 prev_set_tick = gethrtime();
2150 * A negative value will be set to zero in utc_to_tod() so we fake
2151 * a zero here in such a case. This would need to change if the
2152 * behavior of utc_to_tod() changes.
2154 prev_set_tod = ts.tv_sec < 0 ? 0 : ts.tv_sec;
2158 * tod_validate() is used for checking values returned by tod_get().
2159 * Four error cases can be detected by this routine:
2160 * TOD_REVERSED: current tod value is less than previous.
2161 * TOD_STALLED: current tod value hasn't advanced.
2162 * TOD_JUMPED: current tod value advanced too far from previous value.
2163 * TOD_RATECHANGED: the ratio between average tod delta and
2164 * average tick delta has changed.
2166 time_t
2167 tod_validate(time_t tod)
2169 time_t diff_tod;
2170 hrtime_t diff_tick;
2172 long dtick;
2173 int dtick_delta;
2175 int off = 0;
2176 enum tod_fault_type tod_bad = TOD_NOFAULT;
2178 static int firsttime = 1;
2180 static time_t prev_tod = 0;
2181 static hrtime_t prev_tick = 0;
2182 static long dtick_avg = TOD_REF_FREQ;
2184 int cpr_resume_done = 0;
2185 int dr_resume_done = 0;
2187 hrtime_t tick = gethrtime();
2189 ASSERT(MUTEX_HELD(&tod_lock));
2192 * tod_validate_enable is patchable via /etc/system.
2193 * If TOD is already faulted, or if TOD validation is deferred,
2194 * there is nothing to do.
2196 if ((tod_validate_enable == 0) || (tod_faulted != TOD_NOFAULT) ||
2197 tod_validate_deferred) {
2198 return (tod);
2202 * If this is the first time through, we just need to save the tod
2203 * we were called with and hrtime so we can use them next time to
2204 * validate tod_get().
2206 if (firsttime) {
2207 firsttime = 0;
2208 prev_tod = tod;
2209 prev_tick = tick;
2210 return (tod);
2214 * Handle any flags that have been turned on by tod_status_set().
2215 * In the case where a tod_set() is done and then a subsequent
2216 * tod_get() fails (ie, both TOD_SET_DONE and TOD_GET_FAILED are
2217 * true), we treat the TOD_GET_FAILED with precedence by switching
2218 * off the flag, returning tod and leaving TOD_SET_DONE asserted
2219 * until such time as tod_get() completes successfully.
2221 if (tod_status_flag & TOD_GET_FAILED) {
2223 * tod_get() has encountered an issue, possibly transitory,
2224 * when reading TOD. We'll just return the incoming tod
2225 * value (which is actually hrestime.tv_sec in this case)
2226 * and when we get a genuine tod, following a successful
2227 * tod_get(), we can validate using prev_tod and prev_tick.
2229 tod_status_flag &= ~TOD_GET_FAILED;
2230 return (tod);
2231 } else if (tod_status_flag & TOD_SET_DONE) {
2233 * TOD has been modified. Just before the TOD was written,
2234 * tod_set_prev() saved tod and hrtime; we can now use
2235 * those values, prev_set_tod and prev_set_tick, to validate
2236 * the incoming tod that's just been read.
2238 prev_tod = prev_set_tod;
2239 prev_tick = prev_set_tick;
2240 dtick_avg = TOD_REF_FREQ;
2241 tod_status_flag &= ~TOD_SET_DONE;
2243 * If a tod_set() preceded a cpr_suspend() without an
2244 * intervening tod_validate(), we need to ensure that a
2245 * TOD_JUMPED condition is ignored.
2246 * Note this isn't a concern in the case of DR as we've
2247 * just reassigned dtick_avg, above.
2249 if (tod_status_flag & TOD_CPR_RESUME_DONE) {
2250 cpr_resume_done = 1;
2251 tod_status_flag &= ~TOD_CPR_RESUME_DONE;
2253 } else if (tod_status_flag & TOD_CPR_RESUME_DONE) {
2255 * The system's coming back from a checkpoint resume.
2257 cpr_resume_done = 1;
2258 tod_status_flag &= ~TOD_CPR_RESUME_DONE;
2260 * We need to handle the possibility of a CPR suspend
2261 * operation having been initiated whilst a DR event was
2262 * in-flight.
2264 if (tod_status_flag & TOD_DR_RESUME_DONE) {
2265 dr_resume_done = 1;
2266 tod_status_flag &= ~TOD_DR_RESUME_DONE;
2268 } else if (tod_status_flag & TOD_DR_RESUME_DONE) {
2270 * A Dynamic Reconfiguration event has taken place.
2272 dr_resume_done = 1;
2273 tod_status_flag &= ~TOD_DR_RESUME_DONE;
2276 /* test hook */
2277 switch (tod_unit_test) {
2278 case 1: /* for testing jumping tod */
2279 tod += tod_test_injector;
2280 tod_unit_test = 0;
2281 break;
2282 case 2: /* for testing stuck tod bit */
2283 tod |= 1 << tod_test_injector;
2284 tod_unit_test = 0;
2285 break;
2286 case 3: /* for testing stalled tod */
2287 tod = prev_tod;
2288 tod_unit_test = 0;
2289 break;
2290 case 4: /* reset tod fault status */
2291 (void) tod_fault(TOD_NOFAULT, 0);
2292 tod_unit_test = 0;
2293 break;
2294 default:
2295 break;
2298 diff_tod = tod - prev_tod;
2299 diff_tick = tick - prev_tick;
2301 ASSERT(diff_tick >= 0);
2303 if (diff_tod < 0) {
2304 /* ERROR - tod reversed */
2305 tod_bad = TOD_REVERSED;
2306 off = (int)(prev_tod - tod);
2307 } else if (diff_tod == 0) {
2308 /* tod did not advance */
2309 if (diff_tick > TOD_STALL_THRESHOLD) {
2310 /* ERROR - tod stalled */
2311 tod_bad = TOD_STALLED;
2312 } else {
2314 * Make sure we don't update prev_tick
2315 * so that diff_tick is calculated since
2316 * the first diff_tod == 0
2318 return (tod);
2320 } else {
2321 /* calculate dtick */
2322 dtick = diff_tick / diff_tod;
2324 /* update dtick averages */
2325 dtick_avg += ((dtick - dtick_avg) / TOD_FILTER_N);
2328 * Calculate dtick_delta as
2329 * variation from reference freq in quartiles
2331 dtick_delta = (dtick_avg - TOD_REF_FREQ) /
2332 (TOD_REF_FREQ >> 2);
2335 * Even with a perfectly functioning TOD device,
2336 * when the number of elapsed seconds is low the
2337 * algorithm can calculate a rate that is beyond
2338 * tolerance, causing an error. The algorithm is
2339 * inaccurate when elapsed time is low (less than
2340 * 5 seconds).
2342 if (diff_tod > 4) {
2343 if (dtick < TOD_JUMP_THRESHOLD) {
2345 * If we've just done a CPR resume, we detect
2346 * a jump in the TOD but, actually, what's
2347 * happened is that the TOD has been increasing
2348 * whilst the system was suspended and the tick
2349 * count hasn't kept up. We consider the first
2350 * occurrence of this after a resume as normal
2351 * and ignore it; otherwise, in a non-resume
2352 * case, we regard it as a TOD problem.
2354 if (!cpr_resume_done) {
2355 /* ERROR - tod jumped */
2356 tod_bad = TOD_JUMPED;
2357 off = (int)diff_tod;
2360 if (dtick_delta) {
2362 * If we've just done a DR resume, dtick_avg
2363 * can go a bit askew so we reset it and carry
2364 * on; otherwise, the TOD is in error.
2366 if (dr_resume_done) {
2367 dtick_avg = TOD_REF_FREQ;
2368 } else {
2369 /* ERROR - change in clock rate */
2370 tod_bad = TOD_RATECHANGED;
2376 if (tod_bad != TOD_NOFAULT) {
2377 (void) tod_fault(tod_bad, off);
2380 * Disable dosynctodr since we are going to fault
2381 * the TOD chip anyway here
2383 dosynctodr = 0;
2386 * Set tod to the correct value from hrestime
2388 tod = hrestime.tv_sec;
2391 prev_tod = tod;
2392 prev_tick = tick;
2393 return (tod);
2396 static void
2397 calcloadavg(int nrun, uint64_t *hp_ave)
2399 static int64_t f[3] = { 135, 27, 9 };
2400 uint_t i;
2401 int64_t q, r;
2404 * Compute load average over the last 1, 5, and 15 minutes
2405 * (60, 300, and 900 seconds). The constants in f[3] are for
2406 * exponential decay:
2407 * (1 - exp(-1/60)) << 13 = 135,
2408 * (1 - exp(-1/300)) << 13 = 27,
2409 * (1 - exp(-1/900)) << 13 = 9.
2413 * a little hoop-jumping to avoid integer overflow
2415 for (i = 0; i < 3; i++) {
2416 q = (hp_ave[i] >> 16) << 7;
2417 r = (hp_ave[i] & 0xffff) << 7;
2418 hp_ave[i] += ((nrun - q) * f[i] - ((r * f[i]) >> 16)) >> 4;
2423 * lbolt_hybrid() is used by ddi_get_lbolt() and ddi_get_lbolt64() to
2424 * calculate the value of lbolt according to the current mode. In the event
2425 * driven mode (the default), lbolt is calculated by dividing the current hires
2426 * time by the number of nanoseconds per clock tick. In the cyclic driven mode
2427 * an internal variable is incremented at each firing of the lbolt cyclic
2428 * and returned by lbolt_cyclic_driven().
2430 * The system will transition from event to cyclic driven mode when the number
2431 * of calls to lbolt_event_driven() exceeds the (per CPU) threshold within a
2432 * window of time. It does so by reprograming lbolt_cyclic from CY_INFINITY to
2433 * nsec_per_tick. The lbolt cyclic will remain ON while at least one CPU is
2434 * causing enough activity to cross the thresholds.
2436 int64_t
2437 lbolt_bootstrap(void)
2439 return (0);
2442 /* ARGSUSED */
2443 uint_t
2444 lbolt_ev_to_cyclic(caddr_t arg1, caddr_t arg2)
2446 hrtime_t ts, exp;
2447 int ret;
2449 ASSERT(lbolt_hybrid != lbolt_cyclic_driven);
2451 kpreempt_disable();
2453 ts = gethrtime();
2454 lb_info->lbi_internal = (ts/nsec_per_tick);
2457 * Align the next expiration to a clock tick boundary.
2459 exp = ts + nsec_per_tick - 1;
2460 exp = (exp/nsec_per_tick) * nsec_per_tick;
2462 ret = cyclic_reprogram(lb_info->id.lbi_cyclic_id, exp);
2463 ASSERT(ret);
2465 lbolt_hybrid = lbolt_cyclic_driven;
2466 lb_info->lbi_cyc_deactivate = B_FALSE;
2467 lb_info->lbi_cyc_deac_start = lb_info->lbi_internal;
2469 kpreempt_enable();
2471 ret = atomic_dec_32_nv(&lb_info->lbi_token);
2472 ASSERT(ret == 0);
2474 return (1);
2477 int64_t
2478 lbolt_event_driven(void)
2480 hrtime_t ts;
2481 int64_t lb;
2482 int ret, cpu = CPU->cpu_seqid;
2484 ts = gethrtime();
2485 ASSERT(ts > 0);
2487 ASSERT(nsec_per_tick > 0);
2488 lb = (ts/nsec_per_tick);
2491 * Switch to cyclic mode if the number of calls to this routine
2492 * has reached the threshold within the interval.
2494 if ((lb - lb_cpu[cpu].lbc_cnt_start) < lb_info->lbi_thresh_interval) {
2496 if (--lb_cpu[cpu].lbc_counter == 0) {
2498 * Reached the threshold within the interval, reset
2499 * the usage statistics.
2501 lb_cpu[cpu].lbc_counter = lb_info->lbi_thresh_calls;
2502 lb_cpu[cpu].lbc_cnt_start = lb;
2505 * Make sure only one thread reprograms the
2506 * lbolt cyclic and changes the mode.
2508 if (panicstr == NULL &&
2509 atomic_cas_32(&lb_info->lbi_token, 0, 1) == 0) {
2511 if (lbolt_hybrid == lbolt_cyclic_driven) {
2512 ret = atomic_dec_32_nv(
2513 &lb_info->lbi_token);
2514 ASSERT(ret == 0);
2515 } else {
2516 lbolt_softint_post();
2520 } else {
2522 * Exceeded the interval, reset the usage statistics.
2524 lb_cpu[cpu].lbc_counter = lb_info->lbi_thresh_calls;
2525 lb_cpu[cpu].lbc_cnt_start = lb;
2528 ASSERT(lb >= lb_info->lbi_debug_time);
2530 return (lb - lb_info->lbi_debug_time);
2533 int64_t
2534 lbolt_cyclic_driven(void)
2536 int64_t lb = lb_info->lbi_internal;
2537 int cpu;
2540 * If a CPU has already prevented the lbolt cyclic from deactivating
2541 * itself, don't bother tracking the usage. Otherwise check if we're
2542 * within the interval and how the per CPU counter is doing.
2544 if (lb_info->lbi_cyc_deactivate) {
2545 cpu = CPU->cpu_seqid;
2546 if ((lb - lb_cpu[cpu].lbc_cnt_start) <
2547 lb_info->lbi_thresh_interval) {
2549 if (lb_cpu[cpu].lbc_counter == 0)
2551 * Reached the threshold within the interval,
2552 * prevent the lbolt cyclic from turning itself
2553 * off.
2555 lb_info->lbi_cyc_deactivate = B_FALSE;
2556 else
2557 lb_cpu[cpu].lbc_counter--;
2558 } else {
2560 * Only reset the usage statistics when we have
2561 * exceeded the interval.
2563 lb_cpu[cpu].lbc_counter = lb_info->lbi_thresh_calls;
2564 lb_cpu[cpu].lbc_cnt_start = lb;
2568 ASSERT(lb >= lb_info->lbi_debug_time);
2570 return (lb - lb_info->lbi_debug_time);
2574 * The lbolt_cyclic() routine will fire at a nsec_per_tick interval to satisfy
2575 * performance needs of ddi_get_lbolt() and ddi_get_lbolt64() consumers.
2576 * It is inactive by default, and will be activated when switching from event
2577 * to cyclic driven lbolt. The cyclic will turn itself off unless signaled
2578 * by lbolt_cyclic_driven().
2580 static void
2581 lbolt_cyclic(void)
2583 int ret;
2585 lb_info->lbi_internal++;
2587 if (!lbolt_cyc_only) {
2589 if (lb_info->lbi_cyc_deactivate) {
2591 * Switching from cyclic to event driven mode.
2593 if (panicstr == NULL &&
2594 atomic_cas_32(&lb_info->lbi_token, 0, 1) == 0) {
2596 if (lbolt_hybrid == lbolt_event_driven) {
2597 ret = atomic_dec_32_nv(
2598 &lb_info->lbi_token);
2599 ASSERT(ret == 0);
2600 return;
2603 kpreempt_disable();
2605 lbolt_hybrid = lbolt_event_driven;
2606 ret = cyclic_reprogram(
2607 lb_info->id.lbi_cyclic_id,
2608 CY_INFINITY);
2609 ASSERT(ret);
2611 kpreempt_enable();
2613 ret = atomic_dec_32_nv(&lb_info->lbi_token);
2614 ASSERT(ret == 0);
2619 * The lbolt cyclic should not try to deactivate itself before
2620 * the sampling period has elapsed.
2622 if (lb_info->lbi_internal - lb_info->lbi_cyc_deac_start >=
2623 lb_info->lbi_thresh_interval) {
2624 lb_info->lbi_cyc_deactivate = B_TRUE;
2625 lb_info->lbi_cyc_deac_start = lb_info->lbi_internal;
2631 * Since the lbolt service was historically cyclic driven, it must be 'stopped'
2632 * when the system drops into the kernel debugger. lbolt_debug_entry() is
2633 * called by the KDI system claim callbacks to record a hires timestamp at
2634 * debug enter time. lbolt_debug_return() is called by the sistem release
2635 * callbacks to account for the time spent in the debugger. The value is then
2636 * accumulated in the lb_info structure and used by lbolt_event_driven() and
2637 * lbolt_cyclic_driven(), as well as the mdb_get_lbolt() routine.
2639 void
2640 lbolt_debug_entry(void)
2642 if (lbolt_hybrid != lbolt_bootstrap) {
2643 ASSERT(lb_info != NULL);
2644 lb_info->lbi_debug_ts = gethrtime();
2649 * Calculate the time spent in the debugger and add it to the lbolt info
2650 * structure. We also update the internal lbolt value in case we were in
2651 * cyclic driven mode going in.
2653 void
2654 lbolt_debug_return(void)
2656 hrtime_t ts;
2658 if (lbolt_hybrid != lbolt_bootstrap) {
2659 ASSERT(lb_info != NULL);
2660 ASSERT(nsec_per_tick > 0);
2662 ts = gethrtime();
2663 lb_info->lbi_internal = (ts/nsec_per_tick);
2664 lb_info->lbi_debug_time +=
2665 ((ts - lb_info->lbi_debug_ts)/nsec_per_tick);
2667 lb_info->lbi_debug_ts = 0;