From 547ee7926e4107d8c37d768959975f0787a66b3d Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 5 Mar 2012 10:18:00 +0100 Subject: ntpd: fix a case when discipline_jitter = 0 if we step Signed-off-by: Denys Vlasenko --- networking/ntpd.c | 30 +++++++++++++----------------- 1 file changed, 13 insertions(+), 17 deletions(-) (limited to 'networking') diff --git a/networking/ntpd.c b/networking/ntpd.c index b0bfe440f..e9805087c 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -340,7 +340,10 @@ struct globals { double last_update_offset; // c.last double last_update_recv_time; // s.t double discipline_jitter; // c.jitter - double offset_to_jitter_ratio; + /* Since we only compare it with ints, can simplify code + * by not making this variable floating point: + */ + unsigned offset_to_jitter_ratio; //double cluster_offset; // s.offset //double cluster_jitter; // s.jitter #if !USING_KERNEL_PLL_LOOP @@ -1339,7 +1342,7 @@ update_local_clock(peer_t *p) return 1; /* "ok to increase poll interval" */ } #endif - offset = 0; + abs_offset = offset = 0; set_new_values(STATE_SYNC, offset, recv_time); } else { /* abs_offset <= STEP_THRESHOLD */ @@ -1356,10 +1359,6 @@ update_local_clock(peer_t *p) etemp = SQUARE(G.discipline_jitter); dtemp = SQUARE(offset - G.last_update_offset); G.discipline_jitter = SQRT(etemp + (dtemp - etemp) / AVG); - if (G.discipline_jitter < G_precision_sec) - G.discipline_jitter = G_precision_sec; - G.offset_to_jitter_ratio = fabs(offset) / G.discipline_jitter; - VERB3 bb_error_msg("discipline jitter=%f", G.discipline_jitter); switch (G.discipline_state) { case STATE_NSET: @@ -1436,6 +1435,10 @@ update_local_clock(peer_t *p) } } + if (G.discipline_jitter < G_precision_sec) + G.discipline_jitter = G_precision_sec; + G.offset_to_jitter_ratio = abs_offset / G.discipline_jitter; + G.reftime = G.cur_time; G.ntp_status = p->lastpkt_status; G.refid = p->lastpkt_refid; @@ -1473,7 +1476,7 @@ update_local_clock(peer_t *p) memset(&tmx, 0, sizeof(tmx)); if (adjtimex(&tmx) < 0) bb_perror_msg_and_die("adjtimex"); - VERB3 bb_error_msg("p adjtimex freq:%ld offset:%+ld constant:%ld status:0x%x", + bb_error_msg("p adjtimex freq:%ld offset:%+ld constant:%ld status:0x%x", tmx.freq, tmx.offset, tmx.constant, tmx.status); } @@ -1506,7 +1509,7 @@ 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 (tmx.constant > 0 && G.offset_to_jitter_ratio >= TIMECONST_HACK_GATE) tmx.constant--; //tmx.esterror = (uint32_t)(clock_jitter * 1e6); @@ -1520,7 +1523,7 @@ update_local_clock(peer_t *p) VERB3 bb_error_msg("adjtimex:%d freq:%ld offset:%+ld status:0x%x", rc, tmx.freq, tmx.offset, tmx.status); G.kernel_freq_drift = tmx.freq / 65536; - VERB2 bb_error_msg("update peer:%s, offset:%+f, jitter:%f, clock drift:%+.3f ppm, tc:%d", + VERB2 bb_error_msg("update from:%s offset:%+f jitter:%f clock drift:%+.3fppm tc:%d", p->p_dotted, offset, G.discipline_jitter, (double)tmx.freq / 65536, (int)tmx.constant); return 1; /* "ok to increase poll interval" */ @@ -1705,14 +1708,7 @@ recv_and_process_peer_pkt(peer_t *p) * is increased, otherwise it is decreased. A bit of hysteresis * helps calm the dance. Works best using burst mode. */ - VERB4 if (rc > 0) { - bb_error_msg("offset:%+f POLLADJ_GATE*discipline_jitter:%f poll:%s", - q->filter_offset, POLLADJ_GATE * G.discipline_jitter, - fabs(q->filter_offset) < POLLADJ_GATE * G.discipline_jitter - ? "grows" : "falls" - ); - } - if (rc > 0 && G.offset_to_jitter_ratio < POLLADJ_GATE) { + if (rc > 0 && G.offset_to_jitter_ratio <= POLLADJ_GATE) { /* was += G.poll_exp but it is a bit * too optimistic for my taste at high poll_exp's */ G.polladj_count += MINPOLL; -- cgit v1.2.3