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authorPoul-Henning Kamp <phk@FreeBSD.org>1998-01-10 13:16:26 +0000
committerPoul-Henning Kamp <phk@FreeBSD.org>1998-01-10 13:16:26 +0000
commita50ec50568ac69c4286610f2c2cbe27ee8b004e0 (patch)
treeaf9f233576b5dabe47cc9027636af09340edf2e8 /sys/kern/kern_timeout.c
parent7fed2e3a32d6b44adca73179b98730d1938c7767 (diff)
downloadsrc-a50ec50568ac69c4286610f2c2cbe27ee8b004e0.tar.gz
src-a50ec50568ac69c4286610f2c2cbe27ee8b004e0.zip
Notes
Diffstat (limited to 'sys/kern/kern_timeout.c')
-rw-r--r--sys/kern/kern_timeout.c1131
1 files changed, 20 insertions, 1111 deletions
diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c
index b51b29cbe102..c79b3ab1d339 100644
--- a/sys/kern/kern_timeout.c
+++ b/sys/kern/kern_timeout.c
@@ -36,7 +36,7 @@
* SUCH DAMAGE.
*
* @(#)kern_clock.c 8.5 (Berkeley) 1/21/94
- * $Id: kern_clock.c,v 1.47 1997/12/23 16:31:54 nate Exp $
+ * $Id: kern_timeout.c,v 1.48 1998/01/07 12:29:17 phk Exp $
*/
/* Portions of this software are covered by the following: */
@@ -76,613 +76,14 @@
#include <machine/clock.h>
#include <machine/limits.h>
-#ifdef GPROF
-#include <sys/gmon.h>
-#endif
-
-#if defined(SMP) && defined(BETTER_CLOCK)
-#include <machine/smp.h>
-#endif
-
-static void initclocks __P((void *dummy));
-SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL)
-
/* Exported to machdep.c. */
struct callout *callout;
struct callout_list callfree;
int callwheelsize, callwheelbits, callwheelmask;
struct callout_tailq *callwheel;
-
-/* Some of these don't belong here, but it's easiest to concentrate them. */
-#if defined(SMP) && defined(BETTER_CLOCK)
-long cp_time[CPUSTATES];
-#else
-static long cp_time[CPUSTATES];
-#endif
-long dk_seek[DK_NDRIVE];
-static long dk_time[DK_NDRIVE]; /* time busy (in statclock ticks) */
-long dk_wds[DK_NDRIVE];
-long dk_wpms[DK_NDRIVE];
-long dk_xfer[DK_NDRIVE];
-
-int dk_busy;
-int dk_ndrive = 0;
-char dk_names[DK_NDRIVE][DK_NAMELEN];
-
-long tk_cancc;
-long tk_nin;
-long tk_nout;
-long tk_rawcc;
-
-/*
- * Clock handling routines.
- *
- * This code is written to operate with two timers that run independently of
- * each other. The main clock, running hz times per second, is used to keep
- * track of real time. The second timer handles kernel and user profiling,
- * and does resource use estimation. If the second timer is programmable,
- * it is randomized to avoid aliasing between the two clocks. For example,
- * the randomization prevents an adversary from always giving up the cpu
- * just before its quantum expires. Otherwise, it would never accumulate
- * cpu ticks. The mean frequency of the second timer is stathz.
- *
- * If no second timer exists, stathz will be zero; in this case we drive
- * profiling and statistics off the main clock. This WILL NOT be accurate;
- * do not do it unless absolutely necessary.
- *
- * The statistics clock may (or may not) be run at a higher rate while
- * profiling. This profile clock runs at profhz. We require that profhz
- * be an integral multiple of stathz.
- *
- * If the statistics clock is running fast, it must be divided by the ratio
- * profhz/stathz for statistics. (For profiling, every tick counts.)
- */
-
-/*
- * TODO:
- * allocate more timeout table slots when table overflows.
- */
-
-/*
- * Bump a timeval by a small number of usec's.
- */
-#define BUMPTIME(t, usec) { \
- register volatile struct timeval *tp = (t); \
- register long us; \
- \
- tp->tv_usec = us = tp->tv_usec + (usec); \
- if (us >= 1000000) { \
- tp->tv_usec = us - 1000000; \
- tp->tv_sec++; \
- } \
-}
-
-int stathz;
-int profhz;
-static int profprocs;
-int ticks;
static int softticks; /* Like ticks, but for softclock(). */
static struct callout *nextsoftcheck; /* Next callout to be checked. */
-static int psdiv, pscnt; /* prof => stat divider */
-int psratio; /* ratio: prof / stat */
-
-volatile struct timeval time;
-volatile struct timeval mono_time;
-
-/*
- * Phase/frequency-lock loop (PLL/FLL) definitions
- *
- * The following variables are read and set by the ntp_adjtime() system
- * call.
- *
- * time_state shows the state of the system clock, with values defined
- * in the timex.h header file.
- *
- * time_status shows the status of the system clock, with bits defined
- * in the timex.h header file.
- *
- * time_offset is used by the PLL/FLL to adjust the system time in small
- * increments.
- *
- * time_constant determines the bandwidth or "stiffness" of the PLL.
- *
- * time_tolerance determines maximum frequency error or tolerance of the
- * CPU clock oscillator and is a property of the architecture; however,
- * in principle it could change as result of the presence of external
- * discipline signals, for instance.
- *
- * time_precision is usually equal to the kernel tick variable; however,
- * in cases where a precision clock counter or external clock is
- * available, the resolution can be much less than this and depend on
- * whether the external clock is working or not.
- *
- * time_maxerror is initialized by a ntp_adjtime() call and increased by
- * the kernel once each second to reflect the maximum error
- * bound growth.
- *
- * time_esterror is set and read by the ntp_adjtime() call, but
- * otherwise not used by the kernel.
- */
-int time_status = STA_UNSYNC; /* clock status bits */
-int time_state = TIME_OK; /* clock state */
-long time_offset = 0; /* time offset (us) */
-long time_constant = 0; /* pll time constant */
-long time_tolerance = MAXFREQ; /* frequency tolerance (scaled ppm) */
-long time_precision = 1; /* clock precision (us) */
-long time_maxerror = MAXPHASE; /* maximum error (us) */
-long time_esterror = MAXPHASE; /* estimated error (us) */
-
-/*
- * The following variables establish the state of the PLL/FLL and the
- * residual time and frequency offset of the local clock. The scale
- * factors are defined in the timex.h header file.
- *
- * time_phase and time_freq are the phase increment and the frequency
- * increment, respectively, of the kernel time variable at each tick of
- * the clock.
- *
- * time_freq is set via ntp_adjtime() from a value stored in a file when
- * the synchronization daemon is first started. Its value is retrieved
- * via ntp_adjtime() and written to the file about once per hour by the
- * daemon.
- *
- * time_adj is the adjustment added to the value of tick at each timer
- * interrupt and is recomputed from time_phase and time_freq at each
- * seconds rollover.
- *
- * time_reftime is the second's portion of the system time on the last
- * call to ntp_adjtime(). It is used to adjust the time_freq variable
- * and to increase the time_maxerror as the time since last update
- * increases.
- */
-static long time_phase = 0; /* phase offset (scaled us) */
-long time_freq = 0; /* frequency offset (scaled ppm) */
-static long time_adj = 0; /* tick adjust (scaled 1 / hz) */
-static long time_reftime = 0; /* time at last adjustment (s) */
-
-#ifdef PPS_SYNC
-/*
- * The following variables are used only if the kernel PPS discipline
- * code is configured (PPS_SYNC). The scale factors are defined in the
- * timex.h header file.
- *
- * pps_time contains the time at each calibration interval, as read by
- * microtime(). pps_count counts the seconds of the calibration
- * interval, the duration of which is nominally pps_shift in powers of
- * two.
- *
- * pps_offset is the time offset produced by the time median filter
- * pps_tf[], while pps_jitter is the dispersion (jitter) measured by
- * this filter.
- *
- * pps_freq is the frequency offset produced by the frequency median
- * filter pps_ff[], while pps_stabil is the dispersion (wander) measured
- * by this filter.
- *
- * pps_usec is latched from a high resolution counter or external clock
- * at pps_time. Here we want the hardware counter contents only, not the
- * contents plus the time_tv.usec as usual.
- *
- * pps_valid counts the number of seconds since the last PPS update. It
- * is used as a watchdog timer to disable the PPS discipline should the
- * PPS signal be lost.
- *
- * pps_glitch counts the number of seconds since the beginning of an
- * offset burst more than tick/2 from current nominal offset. It is used
- * mainly to suppress error bursts due to priority conflicts between the
- * PPS interrupt and timer interrupt.
- *
- * pps_intcnt counts the calibration intervals for use in the interval-
- * adaptation algorithm. It's just too complicated for words.
- */
-struct timeval pps_time; /* kernel time at last interval */
-long pps_offset = 0; /* pps time offset (us) */
-long pps_jitter = MAXTIME; /* pps time dispersion (jitter) (us) */
-long pps_tf[] = {0, 0, 0}; /* pps time offset median filter (us) */
-long pps_freq = 0; /* frequency offset (scaled ppm) */
-long pps_stabil = MAXFREQ; /* frequency dispersion (scaled ppm) */
-long pps_ff[] = {0, 0, 0}; /* frequency offset median filter */
-long pps_usec = 0; /* microsec counter at last interval */
-long pps_valid = PPS_VALID; /* pps signal watchdog counter */
-int pps_glitch = 0; /* pps signal glitch counter */
-int pps_count = 0; /* calibration interval counter (s) */
-int pps_shift = PPS_SHIFT; /* interval duration (s) (shift) */
-int pps_intcnt = 0; /* intervals at current duration */
-
-/*
- * PPS signal quality monitors
- *
- * pps_jitcnt counts the seconds that have been discarded because the
- * jitter measured by the time median filter exceeds the limit MAXTIME
- * (100 us).
- *
- * pps_calcnt counts the frequency calibration intervals, which are
- * variable from 4 s to 256 s.
- *
- * pps_errcnt counts the calibration intervals which have been discarded
- * because the wander exceeds the limit MAXFREQ (100 ppm) or where the
- * calibration interval jitter exceeds two ticks.
- *
- * pps_stbcnt counts the calibration intervals that have been discarded
- * because the frequency wander exceeds the limit MAXFREQ / 4 (25 us).
- */
-long pps_jitcnt = 0; /* jitter limit exceeded */
-long pps_calcnt = 0; /* calibration intervals */
-long pps_errcnt = 0; /* calibration errors */
-long pps_stbcnt = 0; /* stability limit exceeded */
-#endif /* PPS_SYNC */
-
-/* XXX none of this stuff works under FreeBSD */
-#ifdef EXT_CLOCK
-/*
- * External clock definitions
- *
- * The following definitions and declarations are used only if an
- * external clock (HIGHBALL or TPRO) is configured on the system.
- */
-#define CLOCK_INTERVAL 30 /* CPU clock update interval (s) */
-
-/*
- * The clock_count variable is set to CLOCK_INTERVAL at each PPS
- * interrupt and decremented once each second.
- */
-int clock_count = 0; /* CPU clock counter */
-
-#ifdef HIGHBALL
-/*
- * The clock_offset and clock_cpu variables are used by the HIGHBALL
- * interface. The clock_offset variable defines the offset between
- * system time and the HIGBALL counters. The clock_cpu variable contains
- * the offset between the system clock and the HIGHBALL clock for use in
- * disciplining the kernel time variable.
- */
-extern struct timeval clock_offset; /* Highball clock offset */
-long clock_cpu = 0; /* CPU clock adjust */
-#endif /* HIGHBALL */
-#endif /* EXT_CLOCK */
-
-/*
- * hardupdate() - local clock update
- *
- * This routine is called by ntp_adjtime() to update the local clock
- * phase and frequency. The implementation is of an adaptive-parameter,
- * hybrid phase/frequency-lock loop (PLL/FLL). The routine computes new
- * time and frequency offset estimates for each call. If the kernel PPS
- * discipline code is configured (PPS_SYNC), the PPS signal itself
- * determines the new time offset, instead of the calling argument.
- * Presumably, calls to ntp_adjtime() occur only when the caller
- * believes the local clock is valid within some bound (+-128 ms with
- * NTP). If the caller's time is far different than the PPS time, an
- * argument will ensue, and it's not clear who will lose.
- *
- * For uncompensated quartz crystal oscillatores and nominal update
- * intervals less than 1024 s, operation should be in phase-lock mode
- * (STA_FLL = 0), where the loop is disciplined to phase. For update
- * intervals greater than thiss, operation should be in frequency-lock
- * mode (STA_FLL = 1), where the loop is disciplined to frequency.
- *
- * Note: splclock() is in effect.
- */
-void
-hardupdate(offset)
- long offset;
-{
- long ltemp, mtemp;
-
- if (!(time_status & STA_PLL) && !(time_status & STA_PPSTIME))
- return;
- ltemp = offset;
-#ifdef PPS_SYNC
- if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL)
- ltemp = pps_offset;
-#endif /* PPS_SYNC */
-
- /*
- * Scale the phase adjustment and clamp to the operating range.
- */
- if (ltemp > MAXPHASE)
- time_offset = MAXPHASE << SHIFT_UPDATE;
- else if (ltemp < -MAXPHASE)
- time_offset = -(MAXPHASE << SHIFT_UPDATE);
- else
- time_offset = ltemp << SHIFT_UPDATE;
-
- /*
- * Select whether the frequency is to be controlled and in which
- * mode (PLL or FLL). Clamp to the operating range. Ugly
- * multiply/divide should be replaced someday.
- */
- if (time_status & STA_FREQHOLD || time_reftime == 0)
- time_reftime = time.tv_sec;
- mtemp = time.tv_sec - time_reftime;
- time_reftime = time.tv_sec;
- if (time_status & STA_FLL) {
- if (mtemp >= MINSEC) {
- ltemp = ((time_offset / mtemp) << (SHIFT_USEC -
- SHIFT_UPDATE));
- if (ltemp < 0)
- time_freq -= -ltemp >> SHIFT_KH;
- else
- time_freq += ltemp >> SHIFT_KH;
- }
- } else {
- if (mtemp < MAXSEC) {
- ltemp *= mtemp;
- if (ltemp < 0)
- time_freq -= -ltemp >> (time_constant +
- time_constant + SHIFT_KF -
- SHIFT_USEC);
- else
- time_freq += ltemp >> (time_constant +
- time_constant + SHIFT_KF -
- SHIFT_USEC);
- }
- }
- if (time_freq > time_tolerance)
- time_freq = time_tolerance;
- else if (time_freq < -time_tolerance)
- time_freq = -time_tolerance;
-}
-
-
-
-/*
- * Initialize clock frequencies and start both clocks running.
- */
-/* ARGSUSED*/
-static void
-initclocks(dummy)
- void *dummy;
-{
- register int i;
-
- /*
- * Set divisors to 1 (normal case) and let the machine-specific
- * code do its bit.
- */
- psdiv = pscnt = 1;
- cpu_initclocks();
-
- /*
- * Compute profhz/stathz, and fix profhz if needed.
- */
- i = stathz ? stathz : hz;
- if (profhz == 0)
- profhz = i;
- psratio = profhz / i;
-}
-
-/*
- * The real-time timer, interrupting hz times per second.
- */
-void
-hardclock(frame)
- register struct clockframe *frame;
-{
- register struct proc *p;
-
- p = curproc;
- if (p) {
- register struct pstats *pstats;
-
- /*
- * Run current process's virtual and profile time, as needed.
- */
- pstats = p->p_stats;
- if (CLKF_USERMODE(frame) &&
- timerisset(&pstats->p_timer[ITIMER_VIRTUAL].it_value) &&
- itimerdecr(&pstats->p_timer[ITIMER_VIRTUAL], tick) == 0)
- psignal(p, SIGVTALRM);
- if (timerisset(&pstats->p_timer[ITIMER_PROF].it_value) &&
- itimerdecr(&pstats->p_timer[ITIMER_PROF], tick) == 0)
- psignal(p, SIGPROF);
- }
-
-#if defined(SMP) && defined(BETTER_CLOCK)
- forward_hardclock(pscnt);
-#endif
- /*
- * If no separate statistics clock is available, run it from here.
- */
- if (stathz == 0)
- statclock(frame);
-
- /*
- * Increment the time-of-day.
- */
- ticks++;
- {
- int time_update;
- struct timeval newtime = time;
- long ltemp;
-
- if (timedelta == 0) {
- time_update = CPU_THISTICKLEN(tick);
- } else {
- time_update = CPU_THISTICKLEN(tick) + tickdelta;
- timedelta -= tickdelta;
- }
- BUMPTIME(&mono_time, time_update);
-
- /*
- * Compute the phase adjustment. If the low-order bits
- * (time_phase) of the update overflow, bump the high-order bits
- * (time_update).
- */
- time_phase += time_adj;
- if (time_phase <= -FINEUSEC) {
- ltemp = -time_phase >> SHIFT_SCALE;
- time_phase += ltemp << SHIFT_SCALE;
- time_update -= ltemp;
- }
- else if (time_phase >= FINEUSEC) {
- ltemp = time_phase >> SHIFT_SCALE;
- time_phase -= ltemp << SHIFT_SCALE;
- time_update += ltemp;
- }
-
- newtime.tv_usec += time_update;
- /*
- * On rollover of the second the phase adjustment to be used for
- * the next second is calculated. Also, the maximum error is
- * increased by the tolerance. If the PPS frequency discipline
- * code is present, the phase is increased to compensate for the
- * CPU clock oscillator frequency error.
- *
- * On a 32-bit machine and given parameters in the timex.h
- * header file, the maximum phase adjustment is +-512 ms and
- * maximum frequency offset is a tad less than) +-512 ppm. On a
- * 64-bit machine, you shouldn't need to ask.
- */
- if (newtime.tv_usec >= 1000000) {
- newtime.tv_usec -= 1000000;
- newtime.tv_sec++;
- time_maxerror += time_tolerance >> SHIFT_USEC;
-
- /*
- * Compute the phase adjustment for the next second. In
- * PLL mode, the offset is reduced by a fixed factor
- * times the time constant. In FLL mode the offset is
- * used directly. In either mode, the maximum phase
- * adjustment for each second is clamped so as to spread
- * the adjustment over not more than the number of
- * seconds between updates.
- */
- if (time_offset < 0) {
- ltemp = -time_offset;
- if (!(time_status & STA_FLL))
- ltemp >>= SHIFT_KG + time_constant;
- if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
- ltemp = (MAXPHASE / MINSEC) <<
- SHIFT_UPDATE;
- time_offset += ltemp;
- time_adj = -ltemp << (SHIFT_SCALE - SHIFT_HZ -
- SHIFT_UPDATE);
- } else {
- ltemp = time_offset;
- if (!(time_status & STA_FLL))
- ltemp >>= SHIFT_KG + time_constant;
- if (ltemp > (MAXPHASE / MINSEC) << SHIFT_UPDATE)
- ltemp = (MAXPHASE / MINSEC) <<
- SHIFT_UPDATE;
- time_offset -= ltemp;
- time_adj = ltemp << (SHIFT_SCALE - SHIFT_HZ -
- SHIFT_UPDATE);
- }
-
- /*
- * Compute the frequency estimate and additional phase
- * adjustment due to frequency error for the next
- * second. When the PPS signal is engaged, gnaw on the
- * watchdog counter and update the frequency computed by
- * the pll and the PPS signal.
- */
-#ifdef PPS_SYNC
- pps_valid++;
- if (pps_valid == PPS_VALID) {
- pps_jitter = MAXTIME;
- pps_stabil = MAXFREQ;
- time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
- STA_PPSWANDER | STA_PPSERROR);
- }
- ltemp = time_freq + pps_freq;
-#else
- ltemp = time_freq;
-#endif /* PPS_SYNC */
- if (ltemp < 0)
- time_adj -= -ltemp >>
- (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
- else
- time_adj += ltemp >>
- (SHIFT_USEC + SHIFT_HZ - SHIFT_SCALE);
-
-#if SHIFT_HZ == 7
- /*
- * When the CPU clock oscillator frequency is not a
- * power of two in Hz, the SHIFT_HZ is only an
- * approximate scale factor. In the SunOS kernel, this
- * results in a PLL gain factor of 1/1.28 = 0.78 what it
- * should be. In the following code the overall gain is
- * increased by a factor of 1.25, which results in a
- * residual error less than 3 percent.
- */
- /* Same thing applies for FreeBSD --GAW */
- if (hz == 100) {
- if (time_adj < 0)
- time_adj -= -time_adj >> 2;
- else
- time_adj += time_adj >> 2;
- }
-#endif /* SHIFT_HZ */
-
- /* XXX - this is really bogus, but can't be fixed until
- xntpd's idea of the system clock is fixed to know how
- the user wants leap seconds handled; in the mean time,
- we assume that users of NTP are running without proper
- leap second support (this is now the default anyway) */
- /*
- * Leap second processing. If in leap-insert state at
- * the end of the day, the system clock is set back one
- * second; if in leap-delete state, the system clock is
- * set ahead one second. The microtime() routine or
- * external clock driver will insure that reported time
- * is always monotonic. The ugly divides should be
- * replaced.
- */
- switch (time_state) {
-
- case TIME_OK:
- if (time_status & STA_INS)
- time_state = TIME_INS;
- else if (time_status & STA_DEL)
- time_state = TIME_DEL;
- break;
-
- case TIME_INS:
- if (newtime.tv_sec % 86400 == 0) {
- newtime.tv_sec--;
- time_state = TIME_OOP;
- }
- break;
-
- case TIME_DEL:
- if ((newtime.tv_sec + 1) % 86400 == 0) {
- newtime.tv_sec++;
- time_state = TIME_WAIT;
- }
- break;
-
- case TIME_OOP:
- time_state = TIME_WAIT;
- break;
-
- case TIME_WAIT:
- if (!(time_status & (STA_INS | STA_DEL)))
- time_state = TIME_OK;
- }
- }
- CPU_CLOCKUPDATE(&time, &newtime);
- }
-
- /*
- * Process callouts at a very low cpu priority, so we don't keep the
- * relatively high clock interrupt priority any longer than necessary.
- */
- if (TAILQ_FIRST(&callwheel[ticks & callwheelmask]) != NULL) {
- if (CLKF_BASEPRI(frame)) {
- /*
- * Save the overhead of a software interrupt;
- * it will happen as soon as we return, so do it now.
- */
- (void)splsoftclock();
- softclock();
- } else
- setsoftclock();
- } else if (softticks + 1 == ticks) {
- ++softticks;
- }
-}
/*
* The callout mechanism is based on the work of Adam M. Costello and
@@ -695,13 +96,20 @@ hardclock(frame)
* the 11th ACM Annual Symposium on Operating Systems Principles,
* Austin, Texas Nov 1987.
*/
+
/*
* Software (low priority) clock interrupt.
* Run periodic events from timeout queue.
*/
+
+#ifndef MAX_SOFTCLOCK_STEPS
+#define MAX_SOFTCLOCK_STEPS 100 /* Maximum allowed value of steps. */
+#endif /* MAX_SOFTCLOCK_STEPS */
+
/*ARGSUSED*/
void
-softclock()
+softclock(frame)
+ struct clockframe *frame;
{
register struct callout *c;
register struct callout_tailq *bucket;
@@ -712,9 +120,17 @@ softclock()
* we last allowed interrupts.
*/
- #ifndef MAX_SOFTCLOCK_STEPS
- #define MAX_SOFTCLOCK_STEPS 100 /* Maximum allowed value of steps. */
- #endif /* MAX_SOFTCLOCK_STEPS */
+ if (TAILQ_FIRST(&callwheel[ticks & callwheelmask]) == NULL) {
+ softticks++;
+ return;
+ }
+ if (!CLKF_BASEPRI(frame)) {
+ /* Not yet, come back later */
+ setsoftclock();
+ return;
+ }
+
+ (void)splsoftclock();
steps = 0;
s = splhigh();
@@ -847,513 +263,6 @@ callout_handle_init(struct callout_handle *handle)
handle->callout = NULL;
}
-void
-gettime(struct timeval *tvp)
-{
- int s;
-
- s = splclock();
- /* XXX should use microtime() iff tv_usec is used. */
- *tvp = time;
- splx(s);
-}
-
-/*
- * Compute number of hz until specified time. Used to
- * compute third argument to timeout() from an absolute time.
- */
-int
-hzto(tv)
- struct timeval *tv;
-{
- register unsigned long ticks;
- register long sec, usec;
- int s;
-
- /*
- * If the number of usecs in the whole seconds part of the time
- * difference fits in a long, then the total number of usecs will
- * fit in an unsigned long. Compute the total and convert it to
- * ticks, rounding up and adding 1 to allow for the current tick
- * to expire. Rounding also depends on unsigned long arithmetic
- * to avoid overflow.
- *
- * Otherwise, if the number of ticks in the whole seconds part of
- * the time difference fits in a long, then convert the parts to
- * ticks separately and add, using similar rounding methods and
- * overflow avoidance. This method would work in the previous
- * case but it is slightly slower and assumes that hz is integral.
- *
- * Otherwise, round the time difference down to the maximum
- * representable value.
- *
- * If ints have 32 bits, then the maximum value for any timeout in
- * 10ms ticks is 248 days.
- */
- s = splclock();
- sec = tv->tv_sec - time.tv_sec;
- usec = tv->tv_usec - time.tv_usec;
- splx(s);
- if (usec < 0) {
- sec--;
- usec += 1000000;
- }
- if (sec < 0) {
-#ifdef DIAGNOSTIC
- printf("hzto: negative time difference %ld sec %ld usec\n",
- sec, usec);
-#endif
- ticks = 1;
- } else if (sec <= LONG_MAX / 1000000)
- ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
- / tick + 1;
- else if (sec <= LONG_MAX / hz)
- ticks = sec * hz
- + ((unsigned long)usec + (tick - 1)) / tick + 1;
- else
- ticks = LONG_MAX;
- if (ticks > INT_MAX)
- ticks = INT_MAX;
- return (ticks);
-}
-
-/*
- * Start profiling on a process.
- *
- * Kernel profiling passes proc0 which never exits and hence
- * keeps the profile clock running constantly.
- */
-void
-startprofclock(p)
- register struct proc *p;
-{
- int s;
-
- if ((p->p_flag & P_PROFIL) == 0) {
- p->p_flag |= P_PROFIL;
- if (++profprocs == 1 && stathz != 0) {
- s = splstatclock();
- psdiv = pscnt = psratio;
- setstatclockrate(profhz);
- splx(s);
- }
- }
-}
-
-/*
- * Stop profiling on a process.
- */
-void
-stopprofclock(p)
- register struct proc *p;
-{
- int s;
-
- if (p->p_flag & P_PROFIL) {
- p->p_flag &= ~P_PROFIL;
- if (--profprocs == 0 && stathz != 0) {
- s = splstatclock();
- psdiv = pscnt = 1;
- setstatclockrate(stathz);
- splx(s);
- }
- }
-}
-
-/*
- * Statistics clock. Grab profile sample, and if divider reaches 0,
- * do process and kernel statistics.
- */
-void
-statclock(frame)
- register struct clockframe *frame;
-{
-#ifdef GPROF
- register struct gmonparam *g;
-#endif
- register struct proc *p;
- register int i;
- struct pstats *pstats;
- long rss;
- struct rusage *ru;
- struct vmspace *vm;
-
- if (CLKF_USERMODE(frame)) {
- p = curproc;
- if (p->p_flag & P_PROFIL)
- addupc_intr(p, CLKF_PC(frame), 1);
-#if defined(SMP) && defined(BETTER_CLOCK)
- if (stathz != 0)
- forward_statclock(pscnt);
-#endif
- if (--pscnt > 0)
- return;
- /*
- * Came from user mode; CPU was in user state.
- * If this process is being profiled record the tick.
- */
- p->p_uticks++;
- if (p->p_nice > NZERO)
- cp_time[CP_NICE]++;
- else
- cp_time[CP_USER]++;
- } else {
-#ifdef GPROF
- /*
- * Kernel statistics are just like addupc_intr, only easier.
- */
- g = &_gmonparam;
- if (g->state == GMON_PROF_ON) {
- i = CLKF_PC(frame) - g->lowpc;
- if (i < g->textsize) {
- i /= HISTFRACTION * sizeof(*g->kcount);
- g->kcount[i]++;
- }
- }
-#endif
-#if defined(SMP) && defined(BETTER_CLOCK)
- if (stathz != 0)
- forward_statclock(pscnt);
-#endif
- if (--pscnt > 0)
- return;
- /*
- * Came from kernel mode, so we were:
- * - handling an interrupt,
- * - doing syscall or trap work on behalf of the current
- * user process, or
- * - spinning in the idle loop.
- * Whichever it is, charge the time as appropriate.
- * Note that we charge interrupts to the current process,
- * regardless of whether they are ``for'' that process,
- * so that we know how much of its real time was spent
- * in ``non-process'' (i.e., interrupt) work.
- */
- p = curproc;
- if (CLKF_INTR(frame)) {
- if (p != NULL)
- p->p_iticks++;
- cp_time[CP_INTR]++;
- } else if (p != NULL) {
- p->p_sticks++;
- cp_time[CP_SYS]++;
- } else
- cp_time[CP_IDLE]++;
- }
- pscnt = psdiv;
-
- /*
- * We maintain statistics shown by user-level statistics
- * programs: the amount of time in each cpu state, and
- * the amount of time each of DK_NDRIVE ``drives'' is busy.
- *
- * XXX should either run linked list of drives, or (better)
- * grab timestamps in the start & done code.
- */
- for (i = 0; i < DK_NDRIVE; i++)
- if (dk_busy & (1 << i))
- dk_time[i]++;
-
- /*
- * We adjust the priority of the current process. The priority of
- * a process gets worse as it accumulates CPU time. The cpu usage
- * estimator (p_estcpu) is increased here. The formula for computing
- * priorities (in kern_synch.c) will compute a different value each
- * time p_estcpu increases by 4. The cpu usage estimator ramps up
- * quite quickly when the process is running (linearly), and decays
- * away exponentially, at a rate which is proportionally slower when
- * the system is busy. The basic principal is that the system will
- * 90% forget that the process used a lot of CPU time in 5 * loadav
- * seconds. This causes the system to favor processes which haven't
- * run much recently, and to round-robin among other processes.
- */
- if (p != NULL) {
- p->p_cpticks++;
- if (++p->p_estcpu == 0)
- p->p_estcpu--;
- if ((p->p_estcpu & 3) == 0) {
- resetpriority(p);
- if (p->p_priority >= PUSER)
- p->p_priority = p->p_usrpri;
- }
-
- /* Update resource usage integrals and maximums. */
- if ((pstats = p->p_stats) != NULL &&
- (ru = &pstats->p_ru) != NULL &&
- (vm = p->p_vmspace) != NULL) {
- ru->ru_ixrss += vm->vm_tsize * PAGE_SIZE / 1024;
- ru->ru_idrss += vm->vm_dsize * PAGE_SIZE / 1024;
- ru->ru_isrss += vm->vm_ssize * PAGE_SIZE / 1024;
- rss = vm->vm_pmap.pm_stats.resident_count *
- PAGE_SIZE / 1024;
- if (ru->ru_maxrss < rss)
- ru->ru_maxrss = rss;
- }
- }
-}
-
-/*
- * Return information about system clocks.
- */
-static int
-sysctl_kern_clockrate SYSCTL_HANDLER_ARGS
-{
- struct clockinfo clkinfo;
- /*
- * Construct clockinfo structure.
- */
- clkinfo.hz = hz;
- clkinfo.tick = tick;
- clkinfo.tickadj = tickadj;
- clkinfo.profhz = profhz;
- clkinfo.stathz = stathz ? stathz : hz;
- return (sysctl_handle_opaque(oidp, &clkinfo, sizeof clkinfo, req));
-}
-
-SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate, CTLTYPE_STRUCT|CTLFLAG_RD,
- 0, 0, sysctl_kern_clockrate, "S,clockinfo","");
-
-#ifdef PPS_SYNC
-
-/* We need this ugly monster twice, so lets macroize it... */
-
-#define MEDIAN3(a, m, s) \
- do { \
- if (a[0] > a[1]) { \
- if (a[1] > a[2]) { \
- /* 0 1 2 */ \
- m = a[1]; \
- s = a[0] - a[2]; \
- } else if (a[2] > a[0]) { \
- /* 2 0 1 */ \
- m = a[0]; \
- s = a[2] - a[1]; \
- } else { \
- /* 0 2 1 */ \
- m = a[2]; \
- s = a[0] - a[1]; \
- } \
- } else { \
- if (a[1] < a[2]) { \
- /* 2 1 0 */ \
- m = a[1]; \
- s = a[2] - a[0]; \
- } else if (a[2] < a[0]) { \
- /* 1 0 2 */ \
- m = a[0]; \
- s = a[1] - a[2]; \
- } else { \
- /* 1 2 0 */ \
- m = a[2]; \
- s = a[1] - a[0]; \
- } \
- } \
- } while (0)
-
-/*
- * hardpps() - discipline CPU clock oscillator to external PPS signal
- *
- * This routine is called at each PPS interrupt in order to discipline
- * the CPU clock oscillator to the PPS signal. It measures the PPS phase
- * and leaves it in a handy spot for the hardclock() routine. It
- * integrates successive PPS phase differences and calculates the
- * frequency offset. This is used in hardclock() to discipline the CPU
- * clock oscillator so that intrinsic frequency error is cancelled out.
- * The code requires the caller to capture the time and hardware counter
- * value at the on-time PPS signal transition.
- *
- * Note that, on some Unix systems, this routine runs at an interrupt
- * priority level higher than the timer interrupt routine hardclock().
- * Therefore, the variables used are distinct from the hardclock()
- * variables, except for certain exceptions: The PPS frequency pps_freq
- * and phase pps_offset variables are determined by this routine and
- * updated atomically. The time_tolerance variable can be considered a
- * constant, since it is infrequently changed, and then only when the
- * PPS signal is disabled. The watchdog counter pps_valid is updated
- * once per second by hardclock() and is atomically cleared in this
- * routine.
- */
-void
-hardpps(tvp, p_usec)
- struct timeval *tvp; /* time at PPS */
- long p_usec; /* hardware counter at PPS */
-{
- long u_usec, v_usec, bigtick;
- long cal_sec, cal_usec;
-
- /*
- * An occasional glitch can be produced when the PPS interrupt
- * occurs in the hardclock() routine before the time variable is
- * updated. Here the offset is discarded when the difference
- * between it and the last one is greater than tick/2, but not
- * if the interval since the first discard exceeds 30 s.
- */
- time_status |= STA_PPSSIGNAL;
- time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
- pps_valid = 0;
- u_usec = -tvp->tv_usec;
- if (u_usec < -500000)
- u_usec += 1000000;
- v_usec = pps_offset - u_usec;
- if (v_usec < 0)
- v_usec = -v_usec;
- if (v_usec > (tick >> 1)) {
- if (pps_glitch > MAXGLITCH) {
- pps_glitch = 0;
- pps_tf[2] = u_usec;
- pps_tf[1] = u_usec;
- } else {
- pps_glitch++;
- u_usec = pps_offset;
- }
- } else
- pps_glitch = 0;
-
- /*
- * A three-stage median filter is used to help deglitch the pps
- * time. The median sample becomes the time offset estimate; the
- * difference between the other two samples becomes the time
- * dispersion (jitter) estimate.
- */
- pps_tf[2] = pps_tf[1];
- pps_tf[1] = pps_tf[0];
- pps_tf[0] = u_usec;
-
- MEDIAN3(pps_tf, pps_offset, v_usec);
-
- if (v_usec > MAXTIME)
- pps_jitcnt++;
- v_usec = (v_usec << PPS_AVG) - pps_jitter;
- if (v_usec < 0)
- pps_jitter -= -v_usec >> PPS_AVG;
- else
- pps_jitter += v_usec >> PPS_AVG;
- if (pps_jitter > (MAXTIME >> 1))
- time_status |= STA_PPSJITTER;
-
- /*
- * During the calibration interval adjust the starting time when
- * the tick overflows. At the end of the interval compute the
- * duration of the interval and the difference of the hardware
- * counters at the beginning and end of the interval. This code
- * is deliciously complicated by the fact valid differences may
- * exceed the value of tick when using long calibration
- * intervals and small ticks. Note that the counter can be
- * greater than tick if caught at just the wrong instant, but
- * the values returned and used here are correct.
- */
- bigtick = (long)tick << SHIFT_USEC;
- pps_usec -= pps_freq;
- if (pps_usec >= bigtick)
- pps_usec -= bigtick;
- if (pps_usec < 0)
- pps_usec += bigtick;
- pps_time.tv_sec++;
- pps_count++;
- if (pps_count < (1 << pps_shift))
- return;
- pps_count = 0;
- pps_calcnt++;
- u_usec = p_usec << SHIFT_USEC;
- v_usec = pps_usec - u_usec;
- if (v_usec >= bigtick >> 1)
- v_usec -= bigtick;
- if (v_usec < -(bigtick >> 1))
- v_usec += bigtick;
- if (v_usec < 0)
- v_usec = -(-v_usec >> pps_shift);
- else
- v_usec = v_usec >> pps_shift;
- pps_usec = u_usec;
- cal_sec = tvp->tv_sec;
- cal_usec = tvp->tv_usec;
- cal_sec -= pps_time.tv_sec;
- cal_usec -= pps_time.tv_usec;
- if (cal_usec < 0) {
- cal_usec += 1000000;
- cal_sec--;
- }
- pps_time = *tvp;
-
- /*
- * Check for lost interrupts, noise, excessive jitter and
- * excessive frequency error. The number of timer ticks during
- * the interval may vary +-1 tick. Add to this a margin of one
- * tick for the PPS signal jitter and maximum frequency
- * deviation. If the limits are exceeded, the calibration
- * interval is reset to the minimum and we start over.
- */
- u_usec = (long)tick << 1;
- if (!((cal_sec == -1 && cal_usec > (1000000 - u_usec))
- || (cal_sec == 0 && cal_usec < u_usec))
- || v_usec > time_tolerance || v_usec < -time_tolerance) {
- pps_errcnt++;
- pps_shift = PPS_SHIFT;
- pps_intcnt = 0;
- time_status |= STA_PPSERROR;
- return;
- }
-
- /*
- * A three-stage median filter is used to help deglitch the pps
- * frequency. The median sample becomes the frequency offset
- * estimate; the difference between the other two samples
- * becomes the frequency dispersion (stability) estimate.
- */
- pps_ff[2] = pps_ff[1];
- pps_ff[1] = pps_ff[0];
- pps_ff[0] = v_usec;
-
- MEDIAN3(pps_ff, u_usec, v_usec);
-
- /*
- * Here the frequency dispersion (stability) is updated. If it
- * is less than one-fourth the maximum (MAXFREQ), the frequency
- * offset is updated as well, but clamped to the tolerance. It
- * will be processed later by the hardclock() routine.
- */
- v_usec = (v_usec >> 1) - pps_stabil;
- if (v_usec < 0)
- pps_stabil -= -v_usec >> PPS_AVG;
- else
- pps_stabil += v_usec >> PPS_AVG;
- if (pps_stabil > MAXFREQ >> 2) {
- pps_stbcnt++;
- time_status |= STA_PPSWANDER;
- return;
- }
- if (time_status & STA_PPSFREQ) {
- if (u_usec < 0) {
- pps_freq -= -u_usec >> PPS_AVG;
- if (pps_freq < -time_tolerance)
- pps_freq = -time_tolerance;
- u_usec = -u_usec;
- } else {
- pps_freq += u_usec >> PPS_AVG;
- if (pps_freq > time_tolerance)
- pps_freq = time_tolerance;
- }
- }
-
- /*
- * Here the calibration interval is adjusted. If the maximum
- * time difference is greater than tick / 4, reduce the interval
- * by half. If this is not the case for four consecutive
- * intervals, double the interval.
- */
- if (u_usec << pps_shift > bigtick >> 2) {
- pps_intcnt = 0;
- if (pps_shift > PPS_SHIFT)
- pps_shift--;
- } else if (pps_intcnt >= 4) {
- pps_intcnt = 0;
- if (pps_shift < PPS_SHIFTMAX)
- pps_shift++;
- } else
- pps_intcnt++;
-}
-#endif /* PPS_SYNC */
-
#ifdef APM_FIXUP_CALLTODO
/*
* Adjust the kernel calltodo timeout list. This routine is used after