From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Tue, 6 Jun 2023 08:40:51 +0000 (+0200)
Subject: ntp: use monotonic time for replacement interval
X-Git-Tag: 4.4-pre2~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ab8da7ecb9c1680ec0cf46aba1bc34e1d27d4b14;p=thirdparty%2Fchrony.git

ntp: use monotonic time for replacement interval

Avoid errors in the measured interval due to clock steps.
---

diff --git a/ntp_sources.c b/ntp_sources.c
index f10b3302..2f20299e 100644
--- a/ntp_sources.c
+++ b/ntp_sources.c
@@ -1006,11 +1006,10 @@ resolve_source_replacement(SourceRecord *record, int refreshment)
 void
 NSR_HandleBadSource(IPAddr *address)
 {
-  static struct timespec last_replacement;
-  struct timespec now;
+  static double last_replacement = -1e6;
   SourceRecord *record;
   IPAddr ip_addr;
-  double diff;
+  double now;
   int slot;
 
   if (!find_slot(address, &slot))
@@ -1025,9 +1024,9 @@ NSR_HandleBadSource(IPAddr *address)
     return;
 
   /* Don't resolve names too frequently */
-  SCH_GetLastEventTime(NULL, NULL, &now);
-  diff = UTI_DiffTimespecsToDouble(&now, &last_replacement);
-  if (fabs(diff) < RESOLVE_INTERVAL_UNIT * (1 << MIN_REPLACEMENT_INTERVAL)) {
+  now = SCH_GetLastEventMonoTime();
+  if (now - last_replacement <
+      RESOLVE_INTERVAL_UNIT * (1 << MIN_REPLACEMENT_INTERVAL)) {
     DEBUG_LOG("replacement postponed");
     return;
   }