Default to use 10 seconds as nap interval instead of 1.

Previously, we have a nap interval of 1 second while we have a timeout of
128 seconds by default, which could be an overkill, and for some hardware
the patting action may be expensive.

Note that the choice of nap interval is still arbitrary.  We preferred
a safe value where even when the system is very heavily loaded, the
watchdog should not shoot the system down if it's not really hung.
According to the manual page of Linux's watchdog daemon, the nap interval
time of theirs is 10 seconds, which seems to be a reasonable value --
according to Intel documentation AP-725 (Document Number: 292273-001),
ICH5's maximum timeout is about 37.5 seconds, which the ichwd(4) driver
would set when we requested 128 seconds (although it should probably
feed back this as an error and do not set the timeout).  Since that's
the shortest maximum value, 10 seconds seems to be a right choice for
us too.

Discussed with:	alfred
MFC after:	1 month

2 files changed, 3 insertions, 3 deletions

diff --git a/usr.sbin/watchdogd/watchdogd.8 b/usr.sbin/watchdogd/watchdogd.8
index aa28885..e60f42d 100644
--- a/usr.sbin/watchdogd/watchdogd.8
+++ b/usr.sbin/watchdogd/watchdogd.8
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd October 18, 2014
+.Dd November 16, 2014
 .Dt WATCHDOGD 8
 .Os
 .Sh NAME
@@ -79,7 +79,7 @@ reboot if there are problems with the script.
 The
 .Fl s Ar sleep
 argument can be used to control the sleep period between each execution
-of the check and defaults to one second.
+of the check and defaults to 10 seconds.
 .Pp
 The
 .Fl t Ar timeout
diff --git a/usr.sbin/watchdogd/watchdogd.c b/usr.sbin/watchdogd/watchdogd.c
index 5fd16f5..767aa8e 100644
--- a/usr.sbin/watchdogd/watchdogd.c
+++ b/usr.sbin/watchdogd/watchdogd.c
@@ -87,7 +87,7 @@ static int is_dry_run = 0;  /* do not arm the watchdog, only
 static int do_timedog = 0;
 static int do_syslog = 1;
 static int fd = -1;
-static int nap = 1;
+static int nap = 10;
 static int carp_thresh_seconds = -1;
 static char *test_cmd = NULL;