From 760d035699c4a878f9109544c1d35ea0d5f6b76c Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Sun, 5 Oct 2014 03:10:15 +0200 Subject: ntpd: calculate offset to jitter ratio before updating jitter The offset to jitter ratio is now calculated before updating jitter to make the test more sensitive. function old new delta ntp_init 460 474 +14 update_local_clock 752 764 +12 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 2/0 up/down: 26/0) Total: 26 bytes Signed-off-by: Miroslav Lichvar Signed-off-by: Denys Vlasenko --- networking/ntpd.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/networking/ntpd.c b/networking/ntpd.c index 838a367fe..2d4f076d9 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -1488,12 +1488,19 @@ update_local_clock(peer_t *p) } else { /* abs_offset <= STEP_THRESHOLD */ + /* The ratio is calculated before jitter is updated to make + * poll adjust code more sensitive to large offsets. + */ + G.offset_to_jitter_ratio = abs_offset / G.discipline_jitter; + /* Compute the clock jitter as the RMS of exponentially * weighted offset differences. Used by the poll adjust code. */ 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; switch (G.discipline_state) { case STATE_NSET: @@ -1570,10 +1577,6 @@ 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; @@ -2111,6 +2114,7 @@ static NOINLINE void ntp_init(char **argv) bb_error_msg_and_die(bb_msg_you_must_be_root); /* Set some globals */ + G.discipline_jitter = G_precision_sec; G.stratum = MAXSTRAT; if (BURSTPOLL != 0) G.poll_exp = BURSTPOLL; /* speeds up initial sync */ -- cgit v1.2.3