diff options
| -rw-r--r-- | networking/ntpd.c | 54 |
1 files changed, 36 insertions, 18 deletions
diff --git a/networking/ntpd.c b/networking/ntpd.c index 9732c9b1a..32590a185 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -112,7 +112,7 @@ * * Made some changes to speed up re-syncing after our clock goes bad * (tested with suspending my laptop): - * - if largish offset (>= STEP_THRESHOLD * 8 == 1 sec) is seen + * - if largish offset (>= STEP_THRESHOLD == 1 sec) is seen * from a peer, schedule next query for this peer soon * without drastically lowering poll interval for everybody. * This makes us collect enough data for step much faster: @@ -131,11 +131,14 @@ #define RESPONSE_INTERVAL 16 /* wait for reply up to N secs */ /* Step threshold (sec). std ntpd uses 0.128. + */ +#define STEP_THRESHOLD 1 +/* Slew threshold (sec): adjtimex() won't accept offsets larger than this. * Using exact power of 2 (1/8) results in smaller code */ -#define STEP_THRESHOLD 0.125 +#define SLEW_THRESHOLD 0.125 /* Stepout threshold (sec). std ntpd uses 900 (11 mins (!)) */ -#define WATCH_THRESHOLD 128 +#define WATCH_THRESHOLD 128 /* NB: set WATCH_THRESHOLD to ~60 when debugging to save time) */ //UNUSED: #define PANIC_THRESHOLD 1000 /* panic threshold (sec) */ @@ -143,7 +146,7 @@ * If we got |offset| > BIGOFF from a peer, cap next query interval * for this peer by this many seconds: */ -#define BIGOFF (STEP_THRESHOLD * 8) +#define BIGOFF STEP_THRESHOLD #define BIGOFF_INTERVAL (1 << 7) /* 128 s */ #define FREQ_TOLERANCE 0.000015 /* frequency tolerance (15 PPM) */ @@ -157,10 +160,10 @@ #define MAXPOLL 12 /* maximum poll interval (12: 1.1h, 17: 36.4h). std ntpd uses 17 */ /* * Actively lower poll when we see such big offsets. - * With STEP_THRESHOLD = 0.125, it means we try to sync more aggressively + * With SLEW_THRESHOLD = 0.125, it means we try to sync more aggressively * if offset increases over ~0.04 sec */ -//#define POLLDOWN_OFFSET (STEP_THRESHOLD / 3) +//#define POLLDOWN_OFFSET (SLEW_THRESHOLD / 3) #define MINDISP 0.01 /* minimum dispersion (sec) */ #define MAXDISP 16 /* maximum dispersion (sec) */ #define MAXSTRAT 16 /* maximum stratum (infinity metric) */ @@ -720,7 +723,7 @@ static void reset_peer_stats(peer_t *p, double offset) { int i; - bool small_ofs = fabs(offset) < 16 * STEP_THRESHOLD; + bool small_ofs = fabs(offset) < STEP_THRESHOLD; /* Used to set p->filter_datapoint[i].d_dispersion = MAXDISP * and clear reachable bits, but this proved to be too agressive: @@ -771,7 +774,7 @@ add_peers(const char *s) p->p_fd = -1; p->p_xmt_msg.m_status = MODE_CLIENT | (NTP_VERSION << 3); p->next_action_time = G.cur_time; /* = set_next(p, 0); */ - reset_peer_stats(p, 16 * STEP_THRESHOLD); + reset_peer_stats(p, STEP_THRESHOLD); llist_add_to(&G.ntp_peers, p); G.peer_cnt++; @@ -1638,14 +1641,7 @@ update_local_clock(peer_t *p) tmx.freq = G.discipline_freq_drift * 65536e6; #endif tmx.modes = ADJ_OFFSET | ADJ_STATUS | ADJ_TIMECONST;// | ADJ_MAXERROR | ADJ_ESTERROR; - tmx.offset = (offset * 1000000); /* usec */ - tmx.status = STA_PLL; - if (G.ntp_status & LI_PLUSSEC) - tmx.status |= STA_INS; - if (G.ntp_status & LI_MINUSSEC) - tmx.status |= STA_DEL; - - tmx.constant = (int)G.poll_exp - 4 > 0 ? (int)G.poll_exp - 4 : 0; + tmx.constant = (int)G.poll_exp - 4; /* EXPERIMENTAL. * The below if statement should be unnecessary, but... * It looks like Linux kernel's PLL is far too gentle in changing @@ -1656,8 +1652,27 @@ update_local_clock(peer_t *p) * To be on a safe side, let's do it only if offset is significantly * larger than jitter. */ - if (tmx.constant > 0 && G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE) + if (G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE) tmx.constant--; + tmx.offset = (long)(offset * 1000000); /* usec */ + if (SLEW_THRESHOLD < STEP_THRESHOLD) { + if (tmx.offset > (long)(SLEW_THRESHOLD * 1000000)) { + tmx.offset = (long)(SLEW_THRESHOLD * 1000000); + tmx.constant--; + } + if (tmx.offset < -(long)(SLEW_THRESHOLD * 1000000)) { + tmx.offset = -(long)(SLEW_THRESHOLD * 1000000); + tmx.constant--; + } + } + if (tmx.constant < 0) + tmx.constant = 0; + + tmx.status = STA_PLL; + if (G.ntp_status & LI_PLUSSEC) + tmx.status |= STA_INS; + if (G.ntp_status & LI_MINUSSEC) + tmx.status |= STA_DEL; //tmx.esterror = (uint32_t)(clock_jitter * 1e6); //tmx.maxerror = (uint32_t)((sys_rootdelay / 2 + sys_rootdisp) * 1e6); @@ -1931,6 +1946,9 @@ recv_and_process_peer_pkt(peer_t *p) increase_interval: adjust_poll(MINPOLL); } else { + VERB3 if (rc > 0) + bb_error_msg("want smaller poll interval: offset/jitter ratio > %u", + POLLADJ_GATE); adjust_poll(-G.poll_exp * 2); } } @@ -1939,7 +1957,7 @@ recv_and_process_peer_pkt(peer_t *p) pick_normal_interval: interval = poll_interval(INT_MAX); if (fabs(offset) >= BIGOFF && interval > BIGOFF_INTERVAL) { - /* If we are synced, offsets are less than STEP_THRESHOLD, + /* If we are synced, offsets are less than SLEW_THRESHOLD, * or at the very least not much larger than it. * Now we see a largish one. * Either this peer is feeling bad, or packet got corrupted, |