xref: /dragonfly/sys/kern/kern_clock.c (revision 63ab6604)
1 /*
2  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * Copyright (c) 1997, 1998 Poul-Henning Kamp <phk@FreeBSD.org>
35  * Copyright (c) 1982, 1986, 1991, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  * (c) UNIX System Laboratories, Inc.
38  * All or some portions of this file are derived from material licensed
39  * to the University of California by American Telephone and Telegraph
40  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
41  * the permission of UNIX System Laboratories, Inc.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. All advertising materials mentioning features or use of this software
52  *    must display the following acknowledgement:
53  *	This product includes software developed by the University of
54  *	California, Berkeley and its contributors.
55  * 4. Neither the name of the University nor the names of its contributors
56  *    may be used to endorse or promote products derived from this software
57  *    without specific prior written permission.
58  *
59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69  * SUCH DAMAGE.
70  *
71  *	@(#)kern_clock.c	8.5 (Berkeley) 1/21/94
72  * $FreeBSD: src/sys/kern/kern_clock.c,v 1.105.2.10 2002/10/17 13:19:40 maxim Exp $
73  * $DragonFly: src/sys/kern/kern_clock.c,v 1.62 2008/09/09 04:06:13 dillon Exp $
74  */
75 
76 #include "opt_ntp.h"
77 #include "opt_polling.h"
78 #include "opt_pctrack.h"
79 
80 #include <sys/param.h>
81 #include <sys/systm.h>
82 #include <sys/callout.h>
83 #include <sys/kernel.h>
84 #include <sys/kinfo.h>
85 #include <sys/proc.h>
86 #include <sys/malloc.h>
87 #include <sys/resourcevar.h>
88 #include <sys/signalvar.h>
89 #include <sys/timex.h>
90 #include <sys/timepps.h>
91 #include <vm/vm.h>
92 #include <sys/lock.h>
93 #include <vm/pmap.h>
94 #include <vm/vm_map.h>
95 #include <vm/vm_extern.h>
96 #include <sys/sysctl.h>
97 #include <sys/thread2.h>
98 
99 #include <machine/cpu.h>
100 #include <machine/limits.h>
101 #include <machine/smp.h>
102 
103 #ifdef GPROF
104 #include <sys/gmon.h>
105 #endif
106 
107 #ifdef DEVICE_POLLING
108 extern void init_device_poll_pcpu(int);
109 #endif
110 
111 #ifdef DEBUG_PCTRACK
112 static void do_pctrack(struct intrframe *frame, int which);
113 #endif
114 
115 static void initclocks (void *dummy);
116 SYSINIT(clocks, SI_BOOT2_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
117 
118 /*
119  * Some of these don't belong here, but it's easiest to concentrate them.
120  * Note that cpu_time counts in microseconds, but most userland programs
121  * just compare relative times against the total by delta.
122  */
123 struct kinfo_cputime cputime_percpu[MAXCPU];
124 #ifdef DEBUG_PCTRACK
125 struct kinfo_pcheader cputime_pcheader = { PCTRACK_SIZE, PCTRACK_ARYSIZE };
126 struct kinfo_pctrack cputime_pctrack[MAXCPU][PCTRACK_SIZE];
127 #endif
128 
129 #ifdef SMP
130 static int
131 sysctl_cputime(SYSCTL_HANDLER_ARGS)
132 {
133 	int cpu, error = 0;
134 	size_t size = sizeof(struct kinfo_cputime);
135 
136 	for (cpu = 0; cpu < ncpus; ++cpu) {
137 		if ((error = SYSCTL_OUT(req, &cputime_percpu[cpu], size)))
138 			break;
139 	}
140 
141 	return (error);
142 }
143 SYSCTL_PROC(_kern, OID_AUTO, cputime, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
144 	sysctl_cputime, "S,kinfo_cputime", "CPU time statistics");
145 #else
146 SYSCTL_STRUCT(_kern, OID_AUTO, cputime, CTLFLAG_RD, &cpu_time, kinfo_cputime,
147     "CPU time statistics");
148 #endif
149 
150 /*
151  * boottime is used to calculate the 'real' uptime.  Do not confuse this with
152  * microuptime().  microtime() is not drift compensated.  The real uptime
153  * with compensation is nanotime() - bootime.  boottime is recalculated
154  * whenever the real time is set based on the compensated elapsed time
155  * in seconds (gd->gd_time_seconds).
156  *
157  * The gd_time_seconds and gd_cpuclock_base fields remain fairly monotonic.
158  * Slight adjustments to gd_cpuclock_base are made to phase-lock it to
159  * the real time.
160  */
161 struct timespec boottime;	/* boot time (realtime) for reference only */
162 time_t time_second;		/* read-only 'passive' uptime in seconds */
163 
164 /*
165  * basetime is used to calculate the compensated real time of day.  The
166  * basetime can be modified on a per-tick basis by the adjtime(),
167  * ntp_adjtime(), and sysctl-based time correction APIs.
168  *
169  * Note that frequency corrections can also be made by adjusting
170  * gd_cpuclock_base.
171  *
172  * basetime is a tail-chasing FIFO, updated only by cpu #0.  The FIFO is
173  * used on both SMP and UP systems to avoid MP races between cpu's and
174  * interrupt races on UP systems.
175  */
176 #define BASETIME_ARYSIZE	16
177 #define BASETIME_ARYMASK	(BASETIME_ARYSIZE - 1)
178 static struct timespec basetime[BASETIME_ARYSIZE];
179 static volatile int basetime_index;
180 
181 static int
182 sysctl_get_basetime(SYSCTL_HANDLER_ARGS)
183 {
184 	struct timespec *bt;
185 	int error;
186 	int index;
187 
188 	/*
189 	 * Because basetime data and index may be updated by another cpu,
190 	 * a load fence is required to ensure that the data we read has
191 	 * not been speculatively read relative to a possibly updated index.
192 	 */
193 	index = basetime_index;
194 	cpu_lfence();
195 	bt = &basetime[index];
196 	error = SYSCTL_OUT(req, bt, sizeof(*bt));
197 	return (error);
198 }
199 
200 SYSCTL_STRUCT(_kern, KERN_BOOTTIME, boottime, CTLFLAG_RD,
201     &boottime, timespec, "System boottime");
202 SYSCTL_PROC(_kern, OID_AUTO, basetime, CTLTYPE_STRUCT|CTLFLAG_RD, 0, 0,
203     sysctl_get_basetime, "S,timespec", "System basetime");
204 
205 static void hardclock(systimer_t info, struct intrframe *frame);
206 static void statclock(systimer_t info, struct intrframe *frame);
207 static void schedclock(systimer_t info, struct intrframe *frame);
208 static void getnanotime_nbt(struct timespec *nbt, struct timespec *tsp);
209 
210 int	ticks;			/* system master ticks at hz */
211 int	clocks_running;		/* tsleep/timeout clocks operational */
212 int64_t	nsec_adj;		/* ntpd per-tick adjustment in nsec << 32 */
213 int64_t	nsec_acc;		/* accumulator */
214 
215 /* NTPD time correction fields */
216 int64_t	ntp_tick_permanent;	/* per-tick adjustment in nsec << 32 */
217 int64_t	ntp_tick_acc;		/* accumulator for per-tick adjustment */
218 int64_t	ntp_delta;		/* one-time correction in nsec */
219 int64_t ntp_big_delta = 1000000000;
220 int32_t	ntp_tick_delta;		/* current adjustment rate */
221 int32_t	ntp_default_tick_delta;	/* adjustment rate for ntp_delta */
222 time_t	ntp_leap_second;	/* time of next leap second */
223 int	ntp_leap_insert;	/* whether to insert or remove a second */
224 
225 /*
226  * Finish initializing clock frequencies and start all clocks running.
227  */
228 /* ARGSUSED*/
229 static void
230 initclocks(void *dummy)
231 {
232 	/*psratio = profhz / stathz;*/
233 	initclocks_pcpu();
234 	clocks_running = 1;
235 }
236 
237 /*
238  * Called on a per-cpu basis
239  */
240 void
241 initclocks_pcpu(void)
242 {
243 	struct globaldata *gd = mycpu;
244 
245 	crit_enter();
246 	if (gd->gd_cpuid == 0) {
247 	    gd->gd_time_seconds = 1;
248 	    gd->gd_cpuclock_base = sys_cputimer->count();
249 	} else {
250 	    /* XXX */
251 	    gd->gd_time_seconds = globaldata_find(0)->gd_time_seconds;
252 	    gd->gd_cpuclock_base = globaldata_find(0)->gd_cpuclock_base;
253 	}
254 
255 #ifdef DEVICE_POLLING
256 	init_device_poll_pcpu(gd->gd_cpuid);
257 #endif
258 
259 	/*
260 	 * Use a non-queued periodic systimer to prevent multiple ticks from
261 	 * building up if the sysclock jumps forward (8254 gets reset).  The
262 	 * sysclock will never jump backwards.  Our time sync is based on
263 	 * the actual sysclock, not the ticks count.
264 	 */
265 	systimer_init_periodic_nq(&gd->gd_hardclock, hardclock, NULL, hz);
266 	systimer_init_periodic_nq(&gd->gd_statclock, statclock, NULL, stathz);
267 	/* XXX correct the frequency for scheduler / estcpu tests */
268 	systimer_init_periodic_nq(&gd->gd_schedclock, schedclock,
269 				NULL, ESTCPUFREQ);
270 	crit_exit();
271 }
272 
273 /*
274  * This sets the current real time of day.  Timespecs are in seconds and
275  * nanoseconds.  We do not mess with gd_time_seconds and gd_cpuclock_base,
276  * instead we adjust basetime so basetime + gd_* results in the current
277  * time of day.  This way the gd_* fields are guarenteed to represent
278  * a monotonically increasing 'uptime' value.
279  *
280  * When set_timeofday() is called from userland, the system call forces it
281  * onto cpu #0 since only cpu #0 can update basetime_index.
282  */
283 void
284 set_timeofday(struct timespec *ts)
285 {
286 	struct timespec *nbt;
287 	int ni;
288 
289 	/*
290 	 * XXX SMP / non-atomic basetime updates
291 	 */
292 	crit_enter();
293 	ni = (basetime_index + 1) & BASETIME_ARYMASK;
294 	nbt = &basetime[ni];
295 	nanouptime(nbt);
296 	nbt->tv_sec = ts->tv_sec - nbt->tv_sec;
297 	nbt->tv_nsec = ts->tv_nsec - nbt->tv_nsec;
298 	if (nbt->tv_nsec < 0) {
299 	    nbt->tv_nsec += 1000000000;
300 	    --nbt->tv_sec;
301 	}
302 
303 	/*
304 	 * Note that basetime diverges from boottime as the clock drift is
305 	 * compensated for, so we cannot do away with boottime.  When setting
306 	 * the absolute time of day the drift is 0 (for an instant) and we
307 	 * can simply assign boottime to basetime.
308 	 *
309 	 * Note that nanouptime() is based on gd_time_seconds which is drift
310 	 * compensated up to a point (it is guarenteed to remain monotonically
311 	 * increasing).  gd_time_seconds is thus our best uptime guess and
312 	 * suitable for use in the boottime calculation.  It is already taken
313 	 * into account in the basetime calculation above.
314 	 */
315 	boottime.tv_sec = nbt->tv_sec;
316 	ntp_delta = 0;
317 
318 	/*
319 	 * We now have a new basetime, make sure all other cpus have it,
320 	 * then update the index.
321 	 */
322 	cpu_sfence();
323 	basetime_index = ni;
324 
325 	crit_exit();
326 }
327 
328 /*
329  * Each cpu has its own hardclock, but we only increments ticks and softticks
330  * on cpu #0.
331  *
332  * NOTE! systimer! the MP lock might not be held here.  We can only safely
333  * manipulate objects owned by the current cpu.
334  */
335 static void
336 hardclock(systimer_t info, struct intrframe *frame)
337 {
338 	sysclock_t cputicks;
339 	struct proc *p;
340 	struct globaldata *gd = mycpu;
341 
342 	/*
343 	 * Realtime updates are per-cpu.  Note that timer corrections as
344 	 * returned by microtime() and friends make an additional adjustment
345 	 * using a system-wise 'basetime', but the running time is always
346 	 * taken from the per-cpu globaldata area.  Since the same clock
347 	 * is distributing (XXX SMP) to all cpus, the per-cpu timebases
348 	 * stay in synch.
349 	 *
350 	 * Note that we never allow info->time (aka gd->gd_hardclock.time)
351 	 * to reverse index gd_cpuclock_base, but that it is possible for
352 	 * it to temporarily get behind in the seconds if something in the
353 	 * system locks interrupts for a long period of time.  Since periodic
354 	 * timers count events, though everything should resynch again
355 	 * immediately.
356 	 */
357 	cputicks = info->time - gd->gd_cpuclock_base;
358 	if (cputicks >= sys_cputimer->freq) {
359 		++gd->gd_time_seconds;
360 		gd->gd_cpuclock_base += sys_cputimer->freq;
361 	}
362 
363 	/*
364 	 * The system-wide ticks counter and NTP related timedelta/tickdelta
365 	 * adjustments only occur on cpu #0.  NTP adjustments are accomplished
366 	 * by updating basetime.
367 	 */
368 	if (gd->gd_cpuid == 0) {
369 	    struct timespec *nbt;
370 	    struct timespec nts;
371 	    int leap;
372 	    int ni;
373 
374 	    ++ticks;
375 
376 #if 0
377 	    if (tco->tc_poll_pps)
378 		tco->tc_poll_pps(tco);
379 #endif
380 
381 	    /*
382 	     * Calculate the new basetime index.  We are in a critical section
383 	     * on cpu #0 and can safely play with basetime_index.  Start
384 	     * with the current basetime and then make adjustments.
385 	     */
386 	    ni = (basetime_index + 1) & BASETIME_ARYMASK;
387 	    nbt = &basetime[ni];
388 	    *nbt = basetime[basetime_index];
389 
390 	    /*
391 	     * Apply adjtime corrections.  (adjtime() API)
392 	     *
393 	     * adjtime() only runs on cpu #0 so our critical section is
394 	     * sufficient to access these variables.
395 	     */
396 	    if (ntp_delta != 0) {
397 		nbt->tv_nsec += ntp_tick_delta;
398 		ntp_delta -= ntp_tick_delta;
399 		if ((ntp_delta > 0 && ntp_delta < ntp_tick_delta) ||
400 		    (ntp_delta < 0 && ntp_delta > ntp_tick_delta)) {
401 			ntp_tick_delta = ntp_delta;
402  		}
403  	    }
404 
405 	    /*
406 	     * Apply permanent frequency corrections.  (sysctl API)
407 	     */
408 	    if (ntp_tick_permanent != 0) {
409 		ntp_tick_acc += ntp_tick_permanent;
410 		if (ntp_tick_acc >= (1LL << 32)) {
411 		    nbt->tv_nsec += ntp_tick_acc >> 32;
412 		    ntp_tick_acc -= (ntp_tick_acc >> 32) << 32;
413 		} else if (ntp_tick_acc <= -(1LL << 32)) {
414 		    /* Negate ntp_tick_acc to avoid shifting the sign bit. */
415 		    nbt->tv_nsec -= (-ntp_tick_acc) >> 32;
416 		    ntp_tick_acc += ((-ntp_tick_acc) >> 32) << 32;
417 		}
418  	    }
419 
420 	    if (nbt->tv_nsec >= 1000000000) {
421 		    nbt->tv_sec++;
422 		    nbt->tv_nsec -= 1000000000;
423 	    } else if (nbt->tv_nsec < 0) {
424 		    nbt->tv_sec--;
425 		    nbt->tv_nsec += 1000000000;
426 	    }
427 
428 	    /*
429 	     * Another per-tick compensation.  (for ntp_adjtime() API)
430 	     */
431 	    if (nsec_adj != 0) {
432 		nsec_acc += nsec_adj;
433 		if (nsec_acc >= 0x100000000LL) {
434 		    nbt->tv_nsec += nsec_acc >> 32;
435 		    nsec_acc = (nsec_acc & 0xFFFFFFFFLL);
436 		} else if (nsec_acc <= -0x100000000LL) {
437 		    nbt->tv_nsec -= -nsec_acc >> 32;
438 		    nsec_acc = -(-nsec_acc & 0xFFFFFFFFLL);
439 		}
440 		if (nbt->tv_nsec >= 1000000000) {
441 		    nbt->tv_nsec -= 1000000000;
442 		    ++nbt->tv_sec;
443 		} else if (nbt->tv_nsec < 0) {
444 		    nbt->tv_nsec += 1000000000;
445 		    --nbt->tv_sec;
446 		}
447 	    }
448 
449 	    /************************************************************
450 	     *			LEAP SECOND CORRECTION			*
451 	     ************************************************************
452 	     *
453 	     * Taking into account all the corrections made above, figure
454 	     * out the new real time.  If the seconds field has changed
455 	     * then apply any pending leap-second corrections.
456 	     */
457 	    getnanotime_nbt(nbt, &nts);
458 
459 	    if (time_second != nts.tv_sec) {
460 		/*
461 		 * Apply leap second (sysctl API).  Adjust nts for changes
462 		 * so we do not have to call getnanotime_nbt again.
463 		 */
464 		if (ntp_leap_second) {
465 		    if (ntp_leap_second == nts.tv_sec) {
466 			if (ntp_leap_insert) {
467 			    nbt->tv_sec++;
468 			    nts.tv_sec++;
469 			} else {
470 			    nbt->tv_sec--;
471 			    nts.tv_sec--;
472 			}
473 			ntp_leap_second--;
474 		    }
475 		}
476 
477 		/*
478 		 * Apply leap second (ntp_adjtime() API), calculate a new
479 		 * nsec_adj field.  ntp_update_second() returns nsec_adj
480 		 * as a per-second value but we need it as a per-tick value.
481 		 */
482 		leap = ntp_update_second(time_second, &nsec_adj);
483 		nsec_adj /= hz;
484 		nbt->tv_sec += leap;
485 		nts.tv_sec += leap;
486 
487 		/*
488 		 * Update the time_second 'approximate time' global.
489 		 */
490 		time_second = nts.tv_sec;
491 	    }
492 
493 	    /*
494 	     * Finally, our new basetime is ready to go live!
495 	     */
496 	    cpu_sfence();
497 	    basetime_index = ni;
498 
499 	    /*
500 	     * Figure out how badly the system is starved for memory
501 	     */
502 	    vm_fault_ratecheck();
503 	}
504 
505 	/*
506 	 * softticks are handled for all cpus
507 	 */
508 	hardclock_softtick(gd);
509 
510 	/*
511 	 * The LWKT scheduler will generally allow the current process to
512 	 * return to user mode even if there are other runnable LWKT threads
513 	 * running in kernel mode on behalf of a user process.  This will
514 	 * ensure that those other threads have an opportunity to run in
515 	 * fairly short order (but not instantly).
516 	 */
517 	need_lwkt_resched();
518 
519 	/*
520 	 * ITimer handling is per-tick, per-cpu.  I don't think ksignal()
521 	 * is mpsafe on curproc, so XXX get the mplock.
522 	 */
523 	if ((p = curproc) != NULL && try_mplock()) {
524 		if (frame && CLKF_USERMODE(frame) &&
525 		    timevalisset(&p->p_timer[ITIMER_VIRTUAL].it_value) &&
526 		    itimerdecr(&p->p_timer[ITIMER_VIRTUAL], tick) == 0)
527 			ksignal(p, SIGVTALRM);
528 		if (timevalisset(&p->p_timer[ITIMER_PROF].it_value) &&
529 		    itimerdecr(&p->p_timer[ITIMER_PROF], tick) == 0)
530 			ksignal(p, SIGPROF);
531 		rel_mplock();
532 	}
533 	setdelayed();
534 }
535 
536 /*
537  * The statistics clock typically runs at a 125Hz rate, and is intended
538  * to be frequency offset from the hardclock (typ 100Hz).  It is per-cpu.
539  *
540  * NOTE! systimer! the MP lock might not be held here.  We can only safely
541  * manipulate objects owned by the current cpu.
542  *
543  * The stats clock is responsible for grabbing a profiling sample.
544  * Most of the statistics are only used by user-level statistics programs.
545  * The main exceptions are p->p_uticks, p->p_sticks, p->p_iticks, and
546  * p->p_estcpu.
547  *
548  * Like the other clocks, the stat clock is called from what is effectively
549  * a fast interrupt, so the context should be the thread/process that got
550  * interrupted.
551  */
552 static void
553 statclock(systimer_t info, struct intrframe *frame)
554 {
555 #ifdef GPROF
556 	struct gmonparam *g;
557 	int i;
558 #endif
559 	thread_t td;
560 	struct proc *p;
561 	int bump;
562 	struct timeval tv;
563 	struct timeval *stv;
564 
565 	/*
566 	 * How big was our timeslice relative to the last time?
567 	 */
568 	microuptime(&tv);	/* mpsafe */
569 	stv = &mycpu->gd_stattv;
570 	if (stv->tv_sec == 0) {
571 	    bump = 1;
572 	} else {
573 	    bump = tv.tv_usec - stv->tv_usec +
574 		(tv.tv_sec - stv->tv_sec) * 1000000;
575 	    if (bump < 0)
576 		bump = 0;
577 	    if (bump > 1000000)
578 		bump = 1000000;
579 	}
580 	*stv = tv;
581 
582 	td = curthread;
583 	p = td->td_proc;
584 
585 	if (frame && CLKF_USERMODE(frame)) {
586 		/*
587 		 * Came from userland, handle user time and deal with
588 		 * possible process.
589 		 */
590 		if (p && (p->p_flag & P_PROFIL))
591 			addupc_intr(p, CLKF_PC(frame), 1);
592 		td->td_uticks += bump;
593 
594 		/*
595 		 * Charge the time as appropriate
596 		 */
597 		if (p && p->p_nice > NZERO)
598 			cpu_time.cp_nice += bump;
599 		else
600 			cpu_time.cp_user += bump;
601 	} else {
602 #ifdef GPROF
603 		/*
604 		 * Kernel statistics are just like addupc_intr, only easier.
605 		 */
606 		g = &_gmonparam;
607 		if (g->state == GMON_PROF_ON && frame) {
608 			i = CLKF_PC(frame) - g->lowpc;
609 			if (i < g->textsize) {
610 				i /= HISTFRACTION * sizeof(*g->kcount);
611 				g->kcount[i]++;
612 			}
613 		}
614 #endif
615 		/*
616 		 * Came from kernel mode, so we were:
617 		 * - handling an interrupt,
618 		 * - doing syscall or trap work on behalf of the current
619 		 *   user process, or
620 		 * - spinning in the idle loop.
621 		 * Whichever it is, charge the time as appropriate.
622 		 * Note that we charge interrupts to the current process,
623 		 * regardless of whether they are ``for'' that process,
624 		 * so that we know how much of its real time was spent
625 		 * in ``non-process'' (i.e., interrupt) work.
626 		 *
627 		 * XXX assume system if frame is NULL.  A NULL frame
628 		 * can occur if ipi processing is done from a crit_exit().
629 		 */
630 		if (frame && CLKF_INTR(frame))
631 			td->td_iticks += bump;
632 		else
633 			td->td_sticks += bump;
634 
635 		if (frame && CLKF_INTR(frame)) {
636 #ifdef DEBUG_PCTRACK
637 			do_pctrack(frame, PCTRACK_INT);
638 #endif
639 			cpu_time.cp_intr += bump;
640 		} else {
641 			if (td == &mycpu->gd_idlethread) {
642 				cpu_time.cp_idle += bump;
643 			} else {
644 #ifdef DEBUG_PCTRACK
645 				if (frame)
646 					do_pctrack(frame, PCTRACK_SYS);
647 #endif
648 				cpu_time.cp_sys += bump;
649 			}
650 		}
651 	}
652 }
653 
654 #ifdef DEBUG_PCTRACK
655 /*
656  * Sample the PC when in the kernel or in an interrupt.  User code can
657  * retrieve the information and generate a histogram or other output.
658  */
659 
660 static void
661 do_pctrack(struct intrframe *frame, int which)
662 {
663 	struct kinfo_pctrack *pctrack;
664 
665 	pctrack = &cputime_pctrack[mycpu->gd_cpuid][which];
666 	pctrack->pc_array[pctrack->pc_index & PCTRACK_ARYMASK] =
667 		(void *)CLKF_PC(frame);
668 	++pctrack->pc_index;
669 }
670 
671 static int
672 sysctl_pctrack(SYSCTL_HANDLER_ARGS)
673 {
674 	struct kinfo_pcheader head;
675 	int error;
676 	int cpu;
677 	int ntrack;
678 
679 	head.pc_ntrack = PCTRACK_SIZE;
680 	head.pc_arysize = PCTRACK_ARYSIZE;
681 
682 	if ((error = SYSCTL_OUT(req, &head, sizeof(head))) != 0)
683 		return (error);
684 
685 	for (cpu = 0; cpu < ncpus; ++cpu) {
686 		for (ntrack = 0; ntrack < PCTRACK_SIZE; ++ntrack) {
687 			error = SYSCTL_OUT(req, &cputime_pctrack[cpu][ntrack],
688 					   sizeof(struct kinfo_pctrack));
689 			if (error)
690 				break;
691 		}
692 		if (error)
693 			break;
694 	}
695 	return (error);
696 }
697 SYSCTL_PROC(_kern, OID_AUTO, pctrack, (CTLTYPE_OPAQUE|CTLFLAG_RD), 0, 0,
698 	sysctl_pctrack, "S,kinfo_pcheader", "CPU PC tracking");
699 
700 #endif
701 
702 /*
703  * The scheduler clock typically runs at a 50Hz rate.  NOTE! systimer,
704  * the MP lock might not be held.  We can safely manipulate parts of curproc
705  * but that's about it.
706  *
707  * Each cpu has its own scheduler clock.
708  */
709 static void
710 schedclock(systimer_t info, struct intrframe *frame)
711 {
712 	struct lwp *lp;
713 	struct rusage *ru;
714 	struct vmspace *vm;
715 	long rss;
716 
717 	if ((lp = lwkt_preempted_proc()) != NULL) {
718 		/*
719 		 * Account for cpu time used and hit the scheduler.  Note
720 		 * that this call MUST BE MP SAFE, and the BGL IS NOT HELD
721 		 * HERE.
722 		 */
723 		++lp->lwp_cpticks;
724 		lp->lwp_proc->p_usched->schedulerclock(lp, info->periodic,
725 						       info->time);
726 	}
727 	if ((lp = curthread->td_lwp) != NULL) {
728 		/*
729 		 * Update resource usage integrals and maximums.
730 		 */
731 		if ((ru = &lp->lwp_proc->p_ru) &&
732 		    (vm = lp->lwp_proc->p_vmspace) != NULL) {
733 			ru->ru_ixrss += pgtok(vm->vm_tsize);
734 			ru->ru_idrss += pgtok(vm->vm_dsize);
735 			ru->ru_isrss += pgtok(vm->vm_ssize);
736 			rss = pgtok(vmspace_resident_count(vm));
737 			if (ru->ru_maxrss < rss)
738 				ru->ru_maxrss = rss;
739 		}
740 	}
741 }
742 
743 /*
744  * Compute number of ticks for the specified amount of time.  The
745  * return value is intended to be used in a clock interrupt timed
746  * operation and guarenteed to meet or exceed the requested time.
747  * If the representation overflows, return INT_MAX.  The minimum return
748  * value is 1 ticks and the function will average the calculation up.
749  * If any value greater then 0 microseconds is supplied, a value
750  * of at least 2 will be returned to ensure that a near-term clock
751  * interrupt does not cause the timeout to occur (degenerately) early.
752  *
753  * Note that limit checks must take into account microseconds, which is
754  * done simply by using the smaller signed long maximum instead of
755  * the unsigned long maximum.
756  *
757  * If ints have 32 bits, then the maximum value for any timeout in
758  * 10ms ticks is 248 days.
759  */
760 int
761 tvtohz_high(struct timeval *tv)
762 {
763 	int ticks;
764 	long sec, usec;
765 
766 	sec = tv->tv_sec;
767 	usec = tv->tv_usec;
768 	if (usec < 0) {
769 		sec--;
770 		usec += 1000000;
771 	}
772 	if (sec < 0) {
773 #ifdef DIAGNOSTIC
774 		if (usec > 0) {
775 			sec++;
776 			usec -= 1000000;
777 		}
778 		kprintf("tvtohz_high: negative time difference %ld sec %ld usec\n",
779 		       sec, usec);
780 #endif
781 		ticks = 1;
782 	} else if (sec <= INT_MAX / hz) {
783 		ticks = (int)(sec * hz +
784 			    ((u_long)usec + (tick - 1)) / tick) + 1;
785 	} else {
786 		ticks = INT_MAX;
787 	}
788 	return (ticks);
789 }
790 
791 /*
792  * Compute number of ticks for the specified amount of time, erroring on
793  * the side of it being too low to ensure that sleeping the returned number
794  * of ticks will not result in a late return.
795  *
796  * The supplied timeval may not be negative and should be normalized.  A
797  * return value of 0 is possible if the timeval converts to less then
798  * 1 tick.
799  *
800  * If ints have 32 bits, then the maximum value for any timeout in
801  * 10ms ticks is 248 days.
802  */
803 int
804 tvtohz_low(struct timeval *tv)
805 {
806 	int ticks;
807 	long sec;
808 
809 	sec = tv->tv_sec;
810 	if (sec <= INT_MAX / hz)
811 		ticks = (int)(sec * hz + (u_long)tv->tv_usec / tick);
812 	else
813 		ticks = INT_MAX;
814 	return (ticks);
815 }
816 
817 
818 /*
819  * Start profiling on a process.
820  *
821  * Kernel profiling passes proc0 which never exits and hence
822  * keeps the profile clock running constantly.
823  */
824 void
825 startprofclock(struct proc *p)
826 {
827 	if ((p->p_flag & P_PROFIL) == 0) {
828 		p->p_flag |= P_PROFIL;
829 #if 0	/* XXX */
830 		if (++profprocs == 1 && stathz != 0) {
831 			crit_enter();
832 			psdiv = psratio;
833 			setstatclockrate(profhz);
834 			crit_exit();
835 		}
836 #endif
837 	}
838 }
839 
840 /*
841  * Stop profiling on a process.
842  */
843 void
844 stopprofclock(struct proc *p)
845 {
846 	if (p->p_flag & P_PROFIL) {
847 		p->p_flag &= ~P_PROFIL;
848 #if 0	/* XXX */
849 		if (--profprocs == 0 && stathz != 0) {
850 			crit_enter();
851 			psdiv = 1;
852 			setstatclockrate(stathz);
853 			crit_exit();
854 		}
855 #endif
856 	}
857 }
858 
859 /*
860  * Return information about system clocks.
861  */
862 static int
863 sysctl_kern_clockrate(SYSCTL_HANDLER_ARGS)
864 {
865 	struct kinfo_clockinfo clkinfo;
866 	/*
867 	 * Construct clockinfo structure.
868 	 */
869 	clkinfo.ci_hz = hz;
870 	clkinfo.ci_tick = tick;
871 	clkinfo.ci_tickadj = ntp_default_tick_delta / 1000;
872 	clkinfo.ci_profhz = profhz;
873 	clkinfo.ci_stathz = stathz ? stathz : hz;
874 	return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
875 }
876 
877 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
878 	0, 0, sysctl_kern_clockrate, "S,clockinfo","");
879 
880 /*
881  * We have eight functions for looking at the clock, four for
882  * microseconds and four for nanoseconds.  For each there is fast
883  * but less precise version "get{nano|micro}[up]time" which will
884  * return a time which is up to 1/HZ previous to the call, whereas
885  * the raw version "{nano|micro}[up]time" will return a timestamp
886  * which is as precise as possible.  The "up" variants return the
887  * time relative to system boot, these are well suited for time
888  * interval measurements.
889  *
890  * Each cpu independantly maintains the current time of day, so all
891  * we need to do to protect ourselves from changes is to do a loop
892  * check on the seconds field changing out from under us.
893  *
894  * The system timer maintains a 32 bit count and due to various issues
895  * it is possible for the calculated delta to occassionally exceed
896  * sys_cputimer->freq.  If this occurs the sys_cputimer->freq64_nsec
897  * multiplication can easily overflow, so we deal with the case.  For
898  * uniformity we deal with the case in the usec case too.
899  */
900 void
901 getmicrouptime(struct timeval *tvp)
902 {
903 	struct globaldata *gd = mycpu;
904 	sysclock_t delta;
905 
906 	do {
907 		tvp->tv_sec = gd->gd_time_seconds;
908 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
909 	} while (tvp->tv_sec != gd->gd_time_seconds);
910 
911 	if (delta >= sys_cputimer->freq) {
912 		tvp->tv_sec += delta / sys_cputimer->freq;
913 		delta %= sys_cputimer->freq;
914 	}
915 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
916 	if (tvp->tv_usec >= 1000000) {
917 		tvp->tv_usec -= 1000000;
918 		++tvp->tv_sec;
919 	}
920 }
921 
922 void
923 getnanouptime(struct timespec *tsp)
924 {
925 	struct globaldata *gd = mycpu;
926 	sysclock_t delta;
927 
928 	do {
929 		tsp->tv_sec = gd->gd_time_seconds;
930 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
931 	} while (tsp->tv_sec != gd->gd_time_seconds);
932 
933 	if (delta >= sys_cputimer->freq) {
934 		tsp->tv_sec += delta / sys_cputimer->freq;
935 		delta %= sys_cputimer->freq;
936 	}
937 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
938 }
939 
940 void
941 microuptime(struct timeval *tvp)
942 {
943 	struct globaldata *gd = mycpu;
944 	sysclock_t delta;
945 
946 	do {
947 		tvp->tv_sec = gd->gd_time_seconds;
948 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
949 	} while (tvp->tv_sec != gd->gd_time_seconds);
950 
951 	if (delta >= sys_cputimer->freq) {
952 		tvp->tv_sec += delta / sys_cputimer->freq;
953 		delta %= sys_cputimer->freq;
954 	}
955 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
956 }
957 
958 void
959 nanouptime(struct timespec *tsp)
960 {
961 	struct globaldata *gd = mycpu;
962 	sysclock_t delta;
963 
964 	do {
965 		tsp->tv_sec = gd->gd_time_seconds;
966 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
967 	} while (tsp->tv_sec != gd->gd_time_seconds);
968 
969 	if (delta >= sys_cputimer->freq) {
970 		tsp->tv_sec += delta / sys_cputimer->freq;
971 		delta %= sys_cputimer->freq;
972 	}
973 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
974 }
975 
976 /*
977  * realtime routines
978  */
979 
980 void
981 getmicrotime(struct timeval *tvp)
982 {
983 	struct globaldata *gd = mycpu;
984 	struct timespec *bt;
985 	sysclock_t delta;
986 
987 	do {
988 		tvp->tv_sec = gd->gd_time_seconds;
989 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
990 	} while (tvp->tv_sec != gd->gd_time_seconds);
991 
992 	if (delta >= sys_cputimer->freq) {
993 		tvp->tv_sec += delta / sys_cputimer->freq;
994 		delta %= sys_cputimer->freq;
995 	}
996 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
997 
998 	bt = &basetime[basetime_index];
999 	tvp->tv_sec += bt->tv_sec;
1000 	tvp->tv_usec += bt->tv_nsec / 1000;
1001 	while (tvp->tv_usec >= 1000000) {
1002 		tvp->tv_usec -= 1000000;
1003 		++tvp->tv_sec;
1004 	}
1005 }
1006 
1007 void
1008 getnanotime(struct timespec *tsp)
1009 {
1010 	struct globaldata *gd = mycpu;
1011 	struct timespec *bt;
1012 	sysclock_t delta;
1013 
1014 	do {
1015 		tsp->tv_sec = gd->gd_time_seconds;
1016 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1017 	} while (tsp->tv_sec != gd->gd_time_seconds);
1018 
1019 	if (delta >= sys_cputimer->freq) {
1020 		tsp->tv_sec += delta / sys_cputimer->freq;
1021 		delta %= sys_cputimer->freq;
1022 	}
1023 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1024 
1025 	bt = &basetime[basetime_index];
1026 	tsp->tv_sec += bt->tv_sec;
1027 	tsp->tv_nsec += bt->tv_nsec;
1028 	while (tsp->tv_nsec >= 1000000000) {
1029 		tsp->tv_nsec -= 1000000000;
1030 		++tsp->tv_sec;
1031 	}
1032 }
1033 
1034 static void
1035 getnanotime_nbt(struct timespec *nbt, struct timespec *tsp)
1036 {
1037 	struct globaldata *gd = mycpu;
1038 	sysclock_t delta;
1039 
1040 	do {
1041 		tsp->tv_sec = gd->gd_time_seconds;
1042 		delta = gd->gd_hardclock.time - gd->gd_cpuclock_base;
1043 	} while (tsp->tv_sec != gd->gd_time_seconds);
1044 
1045 	if (delta >= sys_cputimer->freq) {
1046 		tsp->tv_sec += delta / sys_cputimer->freq;
1047 		delta %= sys_cputimer->freq;
1048 	}
1049 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1050 
1051 	tsp->tv_sec += nbt->tv_sec;
1052 	tsp->tv_nsec += nbt->tv_nsec;
1053 	while (tsp->tv_nsec >= 1000000000) {
1054 		tsp->tv_nsec -= 1000000000;
1055 		++tsp->tv_sec;
1056 	}
1057 }
1058 
1059 
1060 void
1061 microtime(struct timeval *tvp)
1062 {
1063 	struct globaldata *gd = mycpu;
1064 	struct timespec *bt;
1065 	sysclock_t delta;
1066 
1067 	do {
1068 		tvp->tv_sec = gd->gd_time_seconds;
1069 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1070 	} while (tvp->tv_sec != gd->gd_time_seconds);
1071 
1072 	if (delta >= sys_cputimer->freq) {
1073 		tvp->tv_sec += delta / sys_cputimer->freq;
1074 		delta %= sys_cputimer->freq;
1075 	}
1076 	tvp->tv_usec = (sys_cputimer->freq64_usec * delta) >> 32;
1077 
1078 	bt = &basetime[basetime_index];
1079 	tvp->tv_sec += bt->tv_sec;
1080 	tvp->tv_usec += bt->tv_nsec / 1000;
1081 	while (tvp->tv_usec >= 1000000) {
1082 		tvp->tv_usec -= 1000000;
1083 		++tvp->tv_sec;
1084 	}
1085 }
1086 
1087 void
1088 nanotime(struct timespec *tsp)
1089 {
1090 	struct globaldata *gd = mycpu;
1091 	struct timespec *bt;
1092 	sysclock_t delta;
1093 
1094 	do {
1095 		tsp->tv_sec = gd->gd_time_seconds;
1096 		delta = sys_cputimer->count() - gd->gd_cpuclock_base;
1097 	} while (tsp->tv_sec != gd->gd_time_seconds);
1098 
1099 	if (delta >= sys_cputimer->freq) {
1100 		tsp->tv_sec += delta / sys_cputimer->freq;
1101 		delta %= sys_cputimer->freq;
1102 	}
1103 	tsp->tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1104 
1105 	bt = &basetime[basetime_index];
1106 	tsp->tv_sec += bt->tv_sec;
1107 	tsp->tv_nsec += bt->tv_nsec;
1108 	while (tsp->tv_nsec >= 1000000000) {
1109 		tsp->tv_nsec -= 1000000000;
1110 		++tsp->tv_sec;
1111 	}
1112 }
1113 
1114 /*
1115  * note: this is not exactly synchronized with real time.  To do that we
1116  * would have to do what microtime does and check for a nanoseconds overflow.
1117  */
1118 time_t
1119 get_approximate_time_t(void)
1120 {
1121 	struct globaldata *gd = mycpu;
1122 	struct timespec *bt;
1123 
1124 	bt = &basetime[basetime_index];
1125 	return(gd->gd_time_seconds + bt->tv_sec);
1126 }
1127 
1128 int
1129 pps_ioctl(u_long cmd, caddr_t data, struct pps_state *pps)
1130 {
1131 	pps_params_t *app;
1132 	struct pps_fetch_args *fapi;
1133 #ifdef PPS_SYNC
1134 	struct pps_kcbind_args *kapi;
1135 #endif
1136 
1137 	switch (cmd) {
1138 	case PPS_IOC_CREATE:
1139 		return (0);
1140 	case PPS_IOC_DESTROY:
1141 		return (0);
1142 	case PPS_IOC_SETPARAMS:
1143 		app = (pps_params_t *)data;
1144 		if (app->mode & ~pps->ppscap)
1145 			return (EINVAL);
1146 		pps->ppsparam = *app;
1147 		return (0);
1148 	case PPS_IOC_GETPARAMS:
1149 		app = (pps_params_t *)data;
1150 		*app = pps->ppsparam;
1151 		app->api_version = PPS_API_VERS_1;
1152 		return (0);
1153 	case PPS_IOC_GETCAP:
1154 		*(int*)data = pps->ppscap;
1155 		return (0);
1156 	case PPS_IOC_FETCH:
1157 		fapi = (struct pps_fetch_args *)data;
1158 		if (fapi->tsformat && fapi->tsformat != PPS_TSFMT_TSPEC)
1159 			return (EINVAL);
1160 		if (fapi->timeout.tv_sec || fapi->timeout.tv_nsec)
1161 			return (EOPNOTSUPP);
1162 		pps->ppsinfo.current_mode = pps->ppsparam.mode;
1163 		fapi->pps_info_buf = pps->ppsinfo;
1164 		return (0);
1165 	case PPS_IOC_KCBIND:
1166 #ifdef PPS_SYNC
1167 		kapi = (struct pps_kcbind_args *)data;
1168 		/* XXX Only root should be able to do this */
1169 		if (kapi->tsformat && kapi->tsformat != PPS_TSFMT_TSPEC)
1170 			return (EINVAL);
1171 		if (kapi->kernel_consumer != PPS_KC_HARDPPS)
1172 			return (EINVAL);
1173 		if (kapi->edge & ~pps->ppscap)
1174 			return (EINVAL);
1175 		pps->kcmode = kapi->edge;
1176 		return (0);
1177 #else
1178 		return (EOPNOTSUPP);
1179 #endif
1180 	default:
1181 		return (ENOTTY);
1182 	}
1183 }
1184 
1185 void
1186 pps_init(struct pps_state *pps)
1187 {
1188 	pps->ppscap |= PPS_TSFMT_TSPEC;
1189 	if (pps->ppscap & PPS_CAPTUREASSERT)
1190 		pps->ppscap |= PPS_OFFSETASSERT;
1191 	if (pps->ppscap & PPS_CAPTURECLEAR)
1192 		pps->ppscap |= PPS_OFFSETCLEAR;
1193 }
1194 
1195 void
1196 pps_event(struct pps_state *pps, sysclock_t count, int event)
1197 {
1198 	struct globaldata *gd;
1199 	struct timespec *tsp;
1200 	struct timespec *osp;
1201 	struct timespec *bt;
1202 	struct timespec ts;
1203 	sysclock_t *pcount;
1204 #ifdef PPS_SYNC
1205 	sysclock_t tcount;
1206 #endif
1207 	sysclock_t delta;
1208 	pps_seq_t *pseq;
1209 	int foff;
1210 	int fhard;
1211 
1212 	gd = mycpu;
1213 
1214 	/* Things would be easier with arrays... */
1215 	if (event == PPS_CAPTUREASSERT) {
1216 		tsp = &pps->ppsinfo.assert_timestamp;
1217 		osp = &pps->ppsparam.assert_offset;
1218 		foff = pps->ppsparam.mode & PPS_OFFSETASSERT;
1219 		fhard = pps->kcmode & PPS_CAPTUREASSERT;
1220 		pcount = &pps->ppscount[0];
1221 		pseq = &pps->ppsinfo.assert_sequence;
1222 	} else {
1223 		tsp = &pps->ppsinfo.clear_timestamp;
1224 		osp = &pps->ppsparam.clear_offset;
1225 		foff = pps->ppsparam.mode & PPS_OFFSETCLEAR;
1226 		fhard = pps->kcmode & PPS_CAPTURECLEAR;
1227 		pcount = &pps->ppscount[1];
1228 		pseq = &pps->ppsinfo.clear_sequence;
1229 	}
1230 
1231 	/* Nothing really happened */
1232 	if (*pcount == count)
1233 		return;
1234 
1235 	*pcount = count;
1236 
1237 	do {
1238 		ts.tv_sec = gd->gd_time_seconds;
1239 		delta = count - gd->gd_cpuclock_base;
1240 	} while (ts.tv_sec != gd->gd_time_seconds);
1241 
1242 	if (delta >= sys_cputimer->freq) {
1243 		ts.tv_sec += delta / sys_cputimer->freq;
1244 		delta %= sys_cputimer->freq;
1245 	}
1246 	ts.tv_nsec = (sys_cputimer->freq64_nsec * delta) >> 32;
1247 	bt = &basetime[basetime_index];
1248 	ts.tv_sec += bt->tv_sec;
1249 	ts.tv_nsec += bt->tv_nsec;
1250 	while (ts.tv_nsec >= 1000000000) {
1251 		ts.tv_nsec -= 1000000000;
1252 		++ts.tv_sec;
1253 	}
1254 
1255 	(*pseq)++;
1256 	*tsp = ts;
1257 
1258 	if (foff) {
1259 		timespecadd(tsp, osp);
1260 		if (tsp->tv_nsec < 0) {
1261 			tsp->tv_nsec += 1000000000;
1262 			tsp->tv_sec -= 1;
1263 		}
1264 	}
1265 #ifdef PPS_SYNC
1266 	if (fhard) {
1267 		/* magic, at its best... */
1268 		tcount = count - pps->ppscount[2];
1269 		pps->ppscount[2] = count;
1270 		if (tcount >= sys_cputimer->freq) {
1271 			delta = (1000000000 * (tcount / sys_cputimer->freq) +
1272 				 sys_cputimer->freq64_nsec *
1273 				 (tcount % sys_cputimer->freq)) >> 32;
1274 		} else {
1275 			delta = (sys_cputimer->freq64_nsec * tcount) >> 32;
1276 		}
1277 		hardpps(tsp, delta);
1278 	}
1279 #endif
1280 }
1281 
1282