diff options
Diffstat (limited to 'ntpd/ntp_loopfilter.c')
| -rw-r--r-- | ntpd/ntp_loopfilter.c | 76 |
1 files changed, 41 insertions, 35 deletions
diff --git a/ntpd/ntp_loopfilter.c b/ntpd/ntp_loopfilter.c index 01772bd1ffe9..b7a742bbd183 100644 --- a/ntpd/ntp_loopfilter.c +++ b/ntpd/ntp_loopfilter.c @@ -15,6 +15,7 @@ #include "ntp_io.h" #include "ntp_unixtime.h" #include "ntp_stdlib.h" +#include "timexsup.h" #include <limits.h> #include <stdio.h> @@ -167,6 +168,9 @@ u_char sys_poll; /* time constant/poll (log2 s) */ int tc_counter; /* jiggle counter */ double last_offset; /* last offset (s) */ +u_int tc_twinlo; /* TC step down not before this time */ +u_int tc_twinhi; /* TC step up not before this time */ + /* * Huff-n'-puff filter variables */ @@ -761,30 +765,21 @@ local_clock( if (ext_enable) { ntv.modes = MOD_STATUS; } else { -#ifdef STA_NANO - ntv.modes = MOD_BITS | MOD_NANO; -#else /* STA_NANO */ ntv.modes = MOD_BITS; -#endif /* STA_NANO */ - if (clock_offset < 0) - dtemp = -.5; - else - dtemp = .5; + ntv.offset = var_long_from_dbl( + clock_offset, &ntv.modes); #ifdef STA_NANO - ntv.offset = (int32)(clock_offset * 1e9 + - dtemp); ntv.constant = sys_poll; #else /* STA_NANO */ - ntv.offset = (int32)(clock_offset * 1e6 + - dtemp); ntv.constant = sys_poll - 4; #endif /* STA_NANO */ if (ntv.constant < 0) ntv.constant = 0; - ntv.esterror = (u_int32)(clock_jitter * 1e6); - ntv.maxerror = (u_int32)((sys_rootdelay / 2 + - sys_rootdisp) * 1e6); + ntv.esterror = usec_long_from_dbl( + clock_jitter); + ntv.maxerror = usec_long_from_dbl( + sys_rootdelay / 2 + sys_rootdisp); ntv.status = STA_PLL; /* @@ -823,22 +818,15 @@ local_clock( ntp_adjtime_error_handler(__func__, &ntv, ntp_adj_ret, errno, hardpps_enable, 0, __LINE__ - 1); } pll_status = ntv.status; -#ifdef STA_NANO - clock_offset = ntv.offset / 1e9; -#else /* STA_NANO */ - clock_offset = ntv.offset / 1e6; -#endif /* STA_NANO */ + clock_offset = dbl_from_var_long(ntv.offset, ntv.status); clock_frequency = FREQTOD(ntv.freq); /* * If the kernel PPS is lit, monitor its performance. */ if (ntv.status & STA_PPSTIME) { -#ifdef STA_NANO - clock_jitter = ntv.jitter / 1e9; -#else /* STA_NANO */ - clock_jitter = ntv.jitter / 1e6; -#endif /* STA_NANO */ + clock_jitter = dbl_from_var_long( + ntv.jitter, ntv.status); } #if defined(STA_NANO) && NTP_API == 4 @@ -888,34 +876,52 @@ local_clock( * increased, otherwise it is decreased. A bit of hysteresis * helps calm the dance. Works best using burst mode. Don't * fiddle with the poll during the startup clamp period. + * [Bug 3615] also observe time gates to avoid eager stepping */ if (freq_cnt > 0) { tc_counter = 0; + tc_twinlo = current_time; + tc_twinhi = current_time; } else if (fabs(clock_offset) < CLOCK_PGATE * clock_jitter) { tc_counter += sys_poll; if (tc_counter > CLOCK_LIMIT) { tc_counter = CLOCK_LIMIT; - if (sys_poll < peer->maxpoll) { - tc_counter = 0; - sys_poll++; - } + if (sys_poll < peer->maxpoll) + sys_poll += (current_time >= tc_twinhi); } } else { tc_counter -= sys_poll << 1; if (tc_counter < -CLOCK_LIMIT) { tc_counter = -CLOCK_LIMIT; - if (sys_poll > peer->minpoll) { - tc_counter = 0; - sys_poll--; - } + if (sys_poll > peer->minpoll) + sys_poll -= (current_time >= tc_twinlo); } } /* * If the time constant has changed, update the poll variables. + * + * [bug 3615] also set new time gates + * The time limit for stepping down will be half the TC interval + * or 60 secs from now, whatever is bigger, and the step up time + * limit will be half the TC interval after the step down limit. + * + * The 'sys_poll' value affects the servo loop gain, and + * overshooting sys_poll slows it down unnecessarily. Stepping + * down too fast also has bad effects. + * + * The 'tc_counter' dance itself is something that *should* + * happen *once* every (1 << sys_poll) seconds, I think, but + * that's not how it works right now, and adding time guards + * seems the least intrusive way to handle this. */ - if (osys_poll != sys_poll) - poll_update(peer, sys_poll); + if (osys_poll != sys_poll) { + u_int deadband = 1u << (sys_poll - 1); + tc_counter = 0; + tc_twinlo = current_time + max(deadband, 60); + tc_twinhi = tc_twinlo + deadband; + poll_update(peer, sys_poll, 0); + } /* * Yibbidy, yibbbidy, yibbidy; that'h all folks. |