diff options
Diffstat (limited to 'sys/kern/kern_clock.c')
| -rw-r--r-- | sys/kern/kern_clock.c | 285 |
1 files changed, 2 insertions, 283 deletions
diff --git a/sys/kern/kern_clock.c b/sys/kern/kern_clock.c index b51b29c..ed85804 100644 --- a/sys/kern/kern_clock.c +++ b/sys/kern/kern_clock.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_clock.c,v 1.48 1998/01/07 12:29:17 phk Exp $ */ /* Portions of this software are covered by the following: */ @@ -87,13 +87,6 @@ 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]; @@ -162,8 +155,6 @@ 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 */ @@ -314,33 +305,6 @@ 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 @@ -665,186 +629,7 @@ hardclock(frame) 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 - * George Varghese, published in a technical report entitled "Redesigning - * the BSD Callout and Timer Facilities" and modified slightly for inclusion - * in FreeBSD by Justin T. Gibbs. The original work on the data structures - * used in this implementation was published by G.Varghese and A. Lauck in - * the paper "Hashed and Hierarchical Timing Wheels: Data Structures for - * the Efficient Implementation of a Timer Facility" in the Proceedings of - * the 11th ACM Annual Symposium on Operating Systems Principles, - * Austin, Texas Nov 1987. - */ -/* - * Software (low priority) clock interrupt. - * Run periodic events from timeout queue. - */ -/*ARGSUSED*/ -void -softclock() -{ - register struct callout *c; - register struct callout_tailq *bucket; - register int s; - register int curticks; - register int steps; /* - * Number of steps taken since - * we last allowed interrupts. - */ - - #ifndef MAX_SOFTCLOCK_STEPS - #define MAX_SOFTCLOCK_STEPS 100 /* Maximum allowed value of steps. */ - #endif /* MAX_SOFTCLOCK_STEPS */ - - steps = 0; - s = splhigh(); - while (softticks != ticks) { - softticks++; - /* - * softticks may be modified by hard clock, so cache - * it while we work on a given bucket. - */ - curticks = softticks; - bucket = &callwheel[curticks & callwheelmask]; - c = TAILQ_FIRST(bucket); - while (c) { - if (c->c_time != curticks) { - c = TAILQ_NEXT(c, c_links.tqe); - ++steps; - if (steps >= MAX_SOFTCLOCK_STEPS) { - nextsoftcheck = c; - /* Give interrupts a chance. */ - splx(s); - s = splhigh(); - c = nextsoftcheck; - steps = 0; - } - } else { - void (*c_func)(void *); - void *c_arg; - - nextsoftcheck = TAILQ_NEXT(c, c_links.tqe); - TAILQ_REMOVE(bucket, c, c_links.tqe); - c_func = c->c_func; - c_arg = c->c_arg; - c->c_func = NULL; - SLIST_INSERT_HEAD(&callfree, c, c_links.sle); - splx(s); - c_func(c_arg); - s = splhigh(); - steps = 0; - c = nextsoftcheck; - } - } - } - nextsoftcheck = NULL; - splx(s); -} - -/* - * timeout -- - * Execute a function after a specified length of time. - * - * untimeout -- - * Cancel previous timeout function call. - * - * callout_handle_init -- - * Initialize a handle so that using it with untimeout is benign. - * - * See AT&T BCI Driver Reference Manual for specification. This - * implementation differs from that one in that although an - * identification value is returned from timeout, the original - * arguments to timeout as well as the identifier are used to - * identify entries for untimeout. - */ -struct callout_handle -timeout(ftn, arg, to_ticks) - timeout_t ftn; - void *arg; - register int to_ticks; -{ - int s; - struct callout *new; - struct callout_handle handle; - - if (to_ticks <= 0) - to_ticks = 1; - - /* Lock out the clock. */ - s = splhigh(); - - /* Fill in the next free callout structure. */ - new = SLIST_FIRST(&callfree); - if (new == NULL) - /* XXX Attempt to malloc first */ - panic("timeout table full"); - - SLIST_REMOVE_HEAD(&callfree, c_links.sle); - new->c_arg = arg; - new->c_func = ftn; - new->c_time = ticks + to_ticks; - TAILQ_INSERT_TAIL(&callwheel[new->c_time & callwheelmask], - new, c_links.tqe); - - splx(s); - handle.callout = new; - return (handle); -} - -void -untimeout(ftn, arg, handle) - timeout_t ftn; - void *arg; - struct callout_handle handle; -{ - register int s; - - /* - * Check for a handle that was initialized - * by callout_handle_init, but never used - * for a real timeout. - */ - if (handle.callout == NULL) - return; - - s = splhigh(); - if ((handle.callout->c_func == ftn) - && (handle.callout->c_arg == arg)) { - if (nextsoftcheck == handle.callout) { - nextsoftcheck = TAILQ_NEXT(handle.callout, c_links.tqe); - } - TAILQ_REMOVE(&callwheel[handle.callout->c_time & callwheelmask], - handle.callout, c_links.tqe); - handle.callout->c_func = NULL; - SLIST_INSERT_HEAD(&callfree, handle.callout, c_links.sle); - } - splx(s); -} - -void -callout_handle_init(struct callout_handle *handle) -{ - handle->callout = NULL; + softclock(frame); } void @@ -1354,69 +1139,3 @@ hardpps(tvp, p_usec) } #endif /* PPS_SYNC */ -#ifdef APM_FIXUP_CALLTODO -/* - * Adjust the kernel calltodo timeout list. This routine is used after - * an APM resume to recalculate the calltodo timer list values with the - * number of hz's we have been sleeping. The next hardclock() will detect - * that there are fired timers and run softclock() to execute them. - * - * Please note, I have not done an exhaustive analysis of what code this - * might break. I am motivated to have my select()'s and alarm()'s that - * have expired during suspend firing upon resume so that the applications - * which set the timer can do the maintanence the timer was for as close - * as possible to the originally intended time. Testing this code for a - * week showed that resuming from a suspend resulted in 22 to 25 timers - * firing, which seemed independant on whether the suspend was 2 hours or - * 2 days. Your milage may vary. - Ken Key <key@cs.utk.edu> - */ -void -adjust_timeout_calltodo(time_change) - struct timeval *time_change; -{ - register struct callout *p; - unsigned long delta_ticks; - int s; - - /* - * How many ticks were we asleep? - * (stolen from hzto()). - */ - - /* Don't do anything */ - if (time_change->tv_sec < 0) - return; - else if (time_change->tv_sec <= LONG_MAX / 1000000) - delta_ticks = (time_change->tv_sec * 1000000 + - time_change->tv_usec + (tick - 1)) / tick + 1; - else if (time_change->tv_sec <= LONG_MAX / hz) - delta_ticks = time_change->tv_sec * hz + - (time_change->tv_usec + (tick - 1)) / tick + 1; - else - delta_ticks = LONG_MAX; - - if (delta_ticks > INT_MAX) - delta_ticks = INT_MAX; - - /* - * Now rip through the timer calltodo list looking for timers - * to expire. - */ - - /* don't collide with softclock() */ - s = splhigh(); - for (p = calltodo.c_next; p != NULL; p = p->c_next) { - p->c_time -= delta_ticks; - - /* Break if the timer had more time on it than delta_ticks */ - if (p->c_time > 0) - break; - - /* take back the ticks the timer didn't use (p->c_time <= 0) */ - delta_ticks = -p->c_time; - } - splx(s); - - return; -} -#endif /* APM_FIXUP_CALLTODO */ |
