From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Mon, 18 Jul 2022 10:50:05 +0000 (+0200)
Subject: ntp: enable sub-second poll sooner with filter option
X-Git-Tag: 4.3-pre1~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3556dadea1b0ccbd7685ebd903eb521229843bf7;p=thirdparty%2Fchrony.git

ntp: enable sub-second poll sooner with filter option

When the minimum round-trip time is checked to enable a sub-second
polling interval, consider also the last sample in the filter to avoid
waiting for the first sample to be accumulated in sourcestats.
---

diff --git a/ntp_core.c b/ntp_core.c
index cd8b6270..6e4745b7 100644
--- a/ntp_core.c
+++ b/ntp_core.c
@@ -783,6 +783,8 @@ NCR_ChangeRemoteAddress(NCR_Instance inst, NTP_Remote_Address *remote_addr, int
 static void
 adjust_poll(NCR_Instance inst, double adj)
 {
+  NTP_Sample last_sample;
+
   inst->poll_score += adj;
 
   if (inst->poll_score >= 1.0) {
@@ -808,7 +810,9 @@ adjust_poll(NCR_Instance inst, double adj)
      or it is not in a local network according to the measured delay */
   if (inst->local_poll < MIN_NONLAN_POLL &&
       (!SRC_IsReachable(inst->source) ||
-       SST_MinRoundTripDelay(SRC_GetSourcestats(inst->source)) > MAX_LAN_PEER_DELAY))
+       (SST_MinRoundTripDelay(SRC_GetSourcestats(inst->source)) > MAX_LAN_PEER_DELAY &&
+        (!inst->filter || !SPF_GetLastSample(inst->filter, &last_sample) ||
+         last_sample.peer_delay > MAX_LAN_PEER_DELAY))))
     inst->local_poll = MIN_NONLAN_POLL;
 }