diff options
Diffstat (limited to 'networking')
| -rw-r--r-- | networking/ntpd.c | 62 |
1 files changed, 38 insertions, 24 deletions
diff --git a/networking/ntpd.c b/networking/ntpd.c index 1c0063ef7..d4754f8ba 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -43,13 +43,13 @@ * max 5 is very talkative (and bloated). 2 is non-bloated, * production level setting. */ -#define MAX_VERBOSE 2 +#define MAX_VERBOSE 2 #define RETRY_INTERVAL 5 /* on error, retry in N secs */ #define QUERYTIME_MAX 15 /* wait for reply up to N secs */ -#define FREQ_TOLERANCE 15e-6 /* % frequency tolerance (15 PPM) */ +#define FREQ_TOLERANCE 0.000015 /* % frequency tolerance (15 PPM) */ #define MINPOLL 4 /* % minimum poll interval (6: 64 s) */ #define MAXPOLL 12 /* % maximum poll interval (12: 1.1h, 17: 36.4h) (was 17) */ #define MINDISP 0.01 /* % minimum dispersion (s) */ @@ -59,34 +59,35 @@ #define MIN_SELECTED 1 /* % minimum intersection survivors */ #define MIN_CLUSTERED 3 /* % minimum cluster survivors */ -#define MAXFREQ 0.000500 /* frequency tolerance (500 PPM) */ +#define MAXDRIFT 0.000500 /* frequency drift we can correct (500 PPM) */ /* Clock discipline parameters and constants */ #define STEP_THRESHOLD 0.128 /* step threshold (s) */ -#define WATCH_THRESHOLD 150 /* stepout threshold (s). std ntpd uses 900 (11 mins (!)) */ +#define WATCH_THRESHOLD 150 /* stepout threshold (s). std ntpd uses 900 (11 mins (!)) */ /* NB: set WATCH_THRESHOLD to ~60 when debugging to save time) */ #define PANIC_THRESHOLD 1000 /* panic threshold (s) */ /* Poll-adjust threshold. * When we see that offset is small enough compared to discipline jitter, * we grow a counter: += MINPOLL. When it goes over POLLADJ_LIMIT, - * we poll_ext++. If offset isn't small, counter -= poll_ext*2, - * and when it goes below -POLLADJ_LIMIT, we poll_ext-- + * we poll_exp++. If offset isn't small, counter -= poll_exp*2, + * and when it goes below -POLLADJ_LIMIT, we poll_exp-- */ -#define POLLADJ_LIMIT 30 +#define POLLADJ_LIMIT 30 /* If offset < POLLADJ_GATE * discipline_jitter, then we can increase * poll interval (we think we can't improve timekeeping * by staying at smaller poll). */ -#define POLLADJ_GATE 4 +#define POLLADJ_GATE 4 /* Compromise Allan intercept (s). doc uses 1500, std ntpd uses 512 */ -#define ALLAN 512 +#define ALLAN 512 /* PLL loop gain */ -#define PLL 65536 +#define PLL 65536 /* FLL loop gain [why it depends on MAXPOLL??] */ -#define FLL (MAXPOLL + 1) +#define FLL (MAXPOLL + 1) /* Parameter averaging constant */ -#define AVG 4 +#define AVG 4 + enum { NTP_VERSION = 4, @@ -251,13 +252,17 @@ struct globals { uint8_t discipline_state; // doc calls it c.state uint8_t poll_exp; // s.poll int polladj_count; // c.count - double discipline_jitter; // c.jitter + long kernel_freq_drift; double last_update_offset; // c.last + double last_update_recv_time; // s.t + double discipline_jitter; // c.jitter +//TODO: add s.jitter - grep for it here and see clock_combine() in doc +#define USING_KERNEL_PLL_LOOP 1 +#if !USING_KERNEL_PLL_LOOP double discipline_freq_drift; // c.freq //TODO: conditionally calculate wander? it's used only for logging double discipline_wander; // c.wander - double last_update_recv_time; // s.t -//TODO: add s.jitter - grep for it here and see clock_combine() in doc +#endif }; #define G (*ptr_to_globals) @@ -1153,25 +1158,27 @@ update_local_clock(peer_t *p, double t) * (Any other state does not reach this, they all return earlier) * By this time, freq_drift and G.last_update_offset are set * to values suitable for adjtimex. - * - * Calculate the new frequency drift and frequency stability (wander). + */ +#if !USING_KERNEL_PLL_LOOP + /* Calculate the new frequency drift and frequency stability (wander). * Compute the clock wander as the RMS of exponentially weighted * frequency differences. This is not used directly, but can, * along with the jitter, be a highly useful monitoring and * debugging tool. */ dtemp = G.discipline_freq_drift + freq_drift; - G.discipline_freq_drift = MAXD(MIND(MAXFREQ, dtemp), -MAXFREQ); + G.discipline_freq_drift = MAXD(MIND(MAXDRIFT, dtemp), -MAXDRIFT); etemp = SQUARE(G.discipline_wander); dtemp = SQUARE(dtemp); G.discipline_wander = SQRT(etemp + (dtemp - etemp) / AVG); + VERB3 bb_error_msg("discipline freq_drift=%.9f(int:%ld corr:%e) wander=%f", + G.discipline_freq_drift, + (long)(G.discipline_freq_drift * 65536e6), + freq_drift, + G.discipline_wander); +#endif VERB3 { - bb_error_msg("discipline freq_drift=%.9f(int:%ld corr:%e) wander=%f", - G.discipline_freq_drift, - (long)(G.discipline_freq_drift * 65536e6), - freq_drift, - G.discipline_wander); memset(&tmx, 0, sizeof(tmx)); if (adjtimex(&tmx) < 0) bb_perror_msg_and_die("adjtimex"); @@ -1192,7 +1199,7 @@ update_local_clock(peer_t *p, double t) } memset(&tmx, 0, sizeof(tmx)); #if 0 -//doesn't work, offset remains 0 (!): +//doesn't work, offset remains 0 (!) in kernel: //ntpd: set adjtimex freq:1786097 tmx.offset:77487 //ntpd: prev adjtimex freq:1786097 tmx.offset:0 //ntpd: cur adjtimex freq:1786097 tmx.offset:0 @@ -1218,14 +1225,21 @@ update_local_clock(peer_t *p, double t) rc = adjtimex(&tmx); if (rc < 0) bb_perror_msg_and_die("adjtimex"); + if (G.kernel_freq_drift != tmx.freq / 65536) { + G.kernel_freq_drift = tmx.freq / 65536; + VERB2 bb_error_msg("kernel clock drift: %ld ppm", G.kernel_freq_drift); + } VERB3 { bb_error_msg("adjtimex:%d freq:%ld offset:%ld constant:%ld status:0x%x", rc, tmx.freq, tmx.offset, tmx.constant, tmx.status); +#if 0 + /* always gives the same output as above msg */ memset(&tmx, 0, sizeof(tmx)); if (adjtimex(&tmx) < 0) bb_perror_msg_and_die("adjtimex"); VERB3 bb_error_msg("c adjtimex freq:%ld offset:%ld constant:%ld status:0x%x", tmx.freq, tmx.offset, tmx.constant, tmx.status); +#endif } // #define STA_MODE 0x4000 /* mode (0 = PLL, 1 = FLL) (ro) */ - ? // it appeared after a while: |