diff options
| author | Miroslav Lichvar <mlichvar@redhat.com> | 2014-10-05 03:10:15 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2014-10-05 03:11:53 +0200 |
| commit | 760d035699c4a878f9109544c1d35ea0d5f6b76c (patch) | |
| tree | e36b94993b03ea937b625e46047b871f62defd93 | |
| parent | cd738711782d5860eeab4e7cefdd1f72dfb83810 (diff) | |
| download | busybox-760d035699c4a878f9109544c1d35ea0d5f6b76c.tar.gz | |
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 <mlichvar@redhat.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | networking/ntpd.c | 12 |
1 files 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 */ |