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ntpd: avoid printing messages between send and recv. good for fast networks

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function                                             old     new   delta
ntpd_main                                            887     929     +42

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2012-03-03 12:15:46 +01:00
parent b124c3491b
commit e8ce285395
1 changed files with 30 additions and 7 deletions
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37
networking/ntpd.c
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@ -107,7 +107,10 @@
#define FREQ_TOLERANCE 0.000015 /* frequency tolerance (15 PPM) */ #define FREQ_TOLERANCE 0.000015 /* frequency tolerance (15 PPM) */
#define BURSTPOLL 0 /* initial poll */ #define BURSTPOLL 0 /* initial poll */
#define MINPOLL 5 /* minimum poll interval. std ntpd uses 6 (6: 64 sec) */ #define MINPOLL 5 /* minimum poll interval. std ntpd uses 6 (6: 64 sec) */
#define BIGPOLL 10 /* drop to lower poll at any trouble (10: 17 min) */ /* If offset > discipline_jitter * POLLADJ_GATE, and poll interval is >= 2^BIGPOLL,
* then it is decreased _at once_. (If < 2^BIGPOLL, it will be decreased _eventually_).
*/
#define BIGPOLL 10 /* 2^10 sec ~= 17 min */
#define MAXPOLL 12 /* maximum poll interval (12: 1.1h, 17: 36.4h). std ntpd uses 17 */ #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. /* Actively lower poll when we see such big offsets.
* With STEP_THRESHOLD = 0.125, it means we try to sync more aggressively * With STEP_THRESHOLD = 0.125, it means we try to sync more aggressively
@ -124,13 +127,13 @@
/* Poll-adjust threshold. /* Poll-adjust threshold.
* When we see that offset is small enough compared to discipline jitter, * When we see that offset is small enough compared to discipline jitter,
* we grow a counter: += MINPOLL. When it goes over POLLADJ_LIMIT, * we grow a counter: += MINPOLL. When counter goes over POLLADJ_LIMIT,
* we poll_exp++. If offset isn't small, counter -= poll_exp*2, * we poll_exp++. If offset isn't small, counter -= poll_exp*2,
* and when it goes below -POLLADJ_LIMIT, we poll_exp-- * and when it goes below -POLLADJ_LIMIT, we poll_exp--.
* (bumped from 30 to 40 since otherwise I often see poll_exp going *2* steps down) * (Bumped from 30 to 40 since otherwise I often see poll_exp going *2* steps down)
*/ */
#define POLLADJ_LIMIT 40 #define POLLADJ_LIMIT 40
/* If offset < POLLADJ_GATE * discipline_jitter, then we can increase /* If offset < discipline_jitter * POLLADJ_GATE, then we decide to increase
* poll interval (we think we can't improve timekeeping * poll interval (we think we can't improve timekeeping
* by staying at smaller poll). * by staying at smaller poll).
*/ */
@ -732,6 +735,12 @@ send_query_to_peer(peer_t *p)
free(local_lsa); free(local_lsa);
} }
/* Emit message _before_ attempted send. Think of a very short
* roundtrip networks: we need to go back to recv loop ASAP,
* to reduce delay. Printing messages after send works against that.
*/
VERB1 bb_error_msg("sending query to %s", p->p_dotted);
/* /*
* Send out a random 64-bit number as our transmit time. The NTP * Send out a random 64-bit number as our transmit time. The NTP
* server will copy said number into the originate field on the * server will copy said number into the originate field on the
@ -759,7 +768,6 @@ send_query_to_peer(peer_t *p)
} }
p->reachable_bits <<= 1; p->reachable_bits <<= 1;
VERB1 bb_error_msg("sent query to %s", p->p_dotted);
set_next(p, RESPONSE_INTERVAL); set_next(p, RESPONSE_INTERVAL);
} }
@ -2077,8 +2085,23 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
timeout++; /* (nextaction - G.cur_time) rounds down, compensating */ timeout++; /* (nextaction - G.cur_time) rounds down, compensating */
/* Here we may block */ /* Here we may block */
VERB2 bb_error_msg("poll %us, sockets:%u, poll interval:%us", timeout, i, 1 << G.poll_exp); VERB2 {
if (i > ENABLE_FEATURE_NTPD_SERVER) {
/* We wait for at least one reply.
* Poll for it, without wasting time for message.
* Since replies often come under 1 second, this also
* reduces clutter in logs.
*/
nfds = poll(pfd, i, 1000);
if (nfds != 0)
goto did_poll;
if (--timeout <= 0)
goto did_poll;
}
bb_error_msg("poll %us, sockets:%u, poll interval:%us", timeout, i, 1 << G.poll_exp);
}
nfds = poll(pfd, i, timeout * 1000); nfds = poll(pfd, i, timeout * 1000);
did_poll:
gettime1900d(); /* sets G.cur_time */ gettime1900d(); /* sets G.cur_time */
if (nfds <= 0) { if (nfds <= 0) {
if (G.script_name && G.cur_time - G.last_script_run > 11*60) { if (G.script_name && G.cur_time - G.last_script_run > 11*60) {