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ntpd: without INITIAL_FREQ_ESTIMATION code, state variable is not needed too

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function                                             old     new   delta
update_local_clock                                   917     872     -45

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-02-21 09:13:05 +01:00
parent 423c4c25d8
commit 2620d38714
1 changed files with 36 additions and 52 deletions
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88
networking/ntpd.c
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@ -461,12 +461,7 @@ struct globals {
#define G_precision_sec 0.002 #define G_precision_sec 0.002
uint8_t stratum; uint8_t stratum;
#define STATE_NSET 0 /* initial state, "nothing is set" */ //uint8_t discipline_state; // doc calls it c.state
//#define STATE_FSET 1 /* frequency set from file */
//#define STATE_SPIK 2 /* spike detected */
//#define STATE_FREQ 3 /* initial frequency */
#define STATE_SYNC 4 /* clock synchronized (normal operation) */
uint8_t discipline_state; // doc calls it c.state
uint8_t poll_exp; // s.poll uint8_t poll_exp; // s.poll
int polladj_count; // c.count int polladj_count; // c.count
int FREQHOLD_cnt; int FREQHOLD_cnt;
@ -1453,15 +1448,14 @@ select_and_cluster(void)
* Local clock discipline and its helpers * Local clock discipline and its helpers
*/ */
static void static void
set_new_values(int disc_state, double offset, double recv_time) set_new_values(double offset, double recv_time)
{ {
/* Enter new state and set state variables. Note we use the time /* Enter new state and set state variables. Note we use the time
* of the last clock filter sample, which must be earlier than * of the last clock filter sample, which must be earlier than
* the current time. * the current time.
*/ */
VERB4 bb_error_msg("disc_state=%d last update offset=%f recv_time=%f", VERB4 bb_error_msg("last update offset=%f recv_time=%f",
disc_state, offset, recv_time); offset, recv_time);
G.discipline_state = disc_state;
G.last_update_offset = offset; G.last_update_offset = offset;
G.last_update_recv_time = recv_time; G.last_update_recv_time = recv_time;
} }
@ -1550,9 +1544,16 @@ update_local_clock(peer_t *p)
recv_time += offset; recv_time += offset;
abs_offset = offset = 0; abs_offset = offset = 0;
set_new_values(STATE_SYNC, offset, recv_time); set_new_values(offset, recv_time);
} else { /* abs_offset <= STEP_THRESHOLD */ } else { /* abs_offset <= STEP_THRESHOLD */
if (option_mask32 & OPT_q) {
/* We were only asked to set time once.
* The clock is precise enough, no need to step.
*/
exit(0);
}
/* The ratio is calculated before jitter is updated to make /* The ratio is calculated before jitter is updated to make
* poll adjust code more sensitive to large offsets. * poll adjust code more sensitive to large offsets.
*/ */
@ -1567,46 +1568,31 @@ update_local_clock(peer_t *p)
if (G.discipline_jitter < G_precision_sec) if (G.discipline_jitter < G_precision_sec)
G.discipline_jitter = G_precision_sec; G.discipline_jitter = G_precision_sec;
switch (G.discipline_state) {
case STATE_NSET:
if (option_mask32 & OPT_q) {
/* We were only asked to set time once.
* The clock is precise enough, no need to step.
*/
exit(0);
}
set_new_values(STATE_SYNC, offset, recv_time);
VERB4 bb_simple_error_msg("transitioning to FREQ, datapoint ignored");
return 0; /* "leave poll interval as is" */
default:
#if !USING_KERNEL_PLL_LOOP #if !USING_KERNEL_PLL_LOOP
/* Compute freq_drift due to PLL and FLL contributions. /* Compute freq_drift due to PLL and FLL contributions.
* *
* The FLL and PLL frequency gain constants * The FLL and PLL frequency gain constants
* depend on the poll interval and Allan * depend on the poll interval and Allan
* intercept. The FLL is not used below one-half * intercept. The FLL is not used below one-half
* the Allan intercept. Above that the loop gain * the Allan intercept. Above that the loop gain
* increases in steps to 1 / AVG. * increases in steps to 1 / AVG.
*/ */
if ((1 << G.poll_exp) > ALLAN / 2) { if ((1 << G.poll_exp) > ALLAN / 2) {
etemp = FLL - G.poll_exp; etemp = FLL - G.poll_exp;
if (etemp < AVG) if (etemp < AVG)
etemp = AVG; etemp = AVG;
freq_drift += (offset - G.last_update_offset) / (MAXD(since_last_update, ALLAN) * etemp); freq_drift += (offset - G.last_update_offset) / (MAXD(since_last_update, ALLAN) * etemp);
}
/* For the PLL the integration interval
* (numerator) is the minimum of the update
* interval and poll interval. This allows
* oversampling, but not undersampling.
*/
etemp = MIND(since_last_update, (1 << G.poll_exp));
dtemp = (4 * PLL) << G.poll_exp;
freq_drift += offset * etemp / SQUARE(dtemp);
#endif
set_new_values(STATE_SYNC, offset, recv_time);
break;
} }
/* For the PLL the integration interval
* (numerator) is the minimum of the update
* interval and poll interval. This allows
* oversampling, but not undersampling.
*/
etemp = MIND(since_last_update, (1 << G.poll_exp));
dtemp = (4 * PLL) << G.poll_exp;
freq_drift += offset * etemp / SQUARE(dtemp);
#endif
set_new_values(offset, recv_time);
if (G.stratum != p->lastpkt_stratum + 1) { if (G.stratum != p->lastpkt_stratum + 1) {
G.stratum = p->lastpkt_stratum + 1; G.stratum = p->lastpkt_stratum + 1;
run_script("stratum", offset); run_script("stratum", offset);
@ -1625,9 +1611,7 @@ update_local_clock(peer_t *p)
G.rootdisp = p->lastpkt_rootdisp + dtemp; G.rootdisp = p->lastpkt_rootdisp + dtemp;
VERB4 bb_error_msg("updating leap/refid/reftime/rootdisp from peer %s", p->p_dotted); VERB4 bb_error_msg("updating leap/refid/reftime/rootdisp from peer %s", p->p_dotted);
/* We are in STATE_SYNC now, but did not do adjtimex yet. /* By this time, freq_drift and offset are set
* (Any other state does not reach this, they all return earlier)
* By this time, freq_drift and offset are set
* to values suitable for adjtimex. * to values suitable for adjtimex.
*/ */
#if !USING_KERNEL_PLL_LOOP #if !USING_KERNEL_PLL_LOOP