when using a timedelta sensor for -s, if the sensor is invalid during

the first query we will never do the settime because
SENSOR_QUERY_INTERVAL (30s) is greater than SETTIME_TIMEOUT (15s).  so
during the settime period only, be more aggressive and use
SETTIME_TIMEOUT/3 for the query interval.
ok henning@

src/usr.sbin/ntpd/ntpd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.99 2009/02/11 01:00:10 stevesk Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.100 2009/05/13 15:08:10 stevesk Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -63,9 +63,10 @@
 #define MAX_SEND_ERRORS		3	/* max send errors before reconnect */
 
 
-#define	SENSOR_DATA_MAXAGE	(15*60)
-#define	SENSOR_QUERY_INTERVAL	30
-#define	SENSOR_SCAN_INTERVAL	(5*60)
+#define	SENSOR_DATA_MAXAGE		(15*60)
+#define	SENSOR_QUERY_INTERVAL		30
+#define	SENSOR_QUERY_INTERVAL_SETTIME	(SETTIME_TIMEOUT/3)
+#define	SENSOR_SCAN_INTERVAL		(5*60)
 
 enum client_state {
 	STATE_NONE,

src/usr.sbin/ntpd/sensors.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: sensors.c,v 1.43 2009/02/08 23:57:08 stevesk Exp $ */
+/*	$OpenBSD: sensors.c,v 1.44 2009/05/13 15:08:10 stevesk Exp $ */
 
 /*
  * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
@@ -154,7 +154,10 @@ sensor_query(struct ntp_sensor *s)
 	char		 dxname[MAXDEVNAMLEN];
 	struct sensor	 sensor;
 
-	s->next = getmonotime() + SENSOR_QUERY_INTERVAL;
+	if (conf->settime)
+		s->next = getmonotime() + SENSOR_QUERY_INTERVAL_SETTIME;
+	else
+		s->next = getmonotime() + SENSOR_QUERY_INTERVAL;
 
 	/* rcvd is walltime here, monotime in client.c. not used elsewhere */
 	if (s->update.rcvd < time(NULL) - SENSOR_DATA_MAXAGE)