HZ now defaults to 1000 on many architectures, so update NOTES to reflect

that.

MFC after:	3 days
PR:		113670
Submitted by:	Ighighi <ighighi at gmail.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index dfa3d8d..91cf86f 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -880,8 +880,8 @@ options 	ACCEPT_FILTER_HTTP
 
 # DUMMYNET enables the "dummynet" bandwidth limiter.  You need IPFIREWALL
 # as well.  See dummynet(4) and ipfw(8) for more info.  When you run
-# DUMMYNET it is advisable to also have "options HZ=1000" to achieve a
-# smoother scheduling of the traffic.
+# DUMMYNET it is advisable to also have at least "options HZ=1000" to achieve
+# a smooth scheduling of the traffic.
 options 	DUMMYNET
 
 # Zero copy sockets support.  This enables "zero copy" for sending and
@@ -1110,13 +1110,13 @@ options 	MAC_TEST
 # CLOCK OPTIONS
 
 # The granularity of operation is controlled by the kernel option HZ whose
-# default value (100) means a granularity of 10ms (1s/HZ).
-# Some subsystems, such as DUMMYNET, might benefit from a smaller
-# granularity such as 1ms or less, for a smoother scheduling of packets.
-# Consider, however, that reducing the granularity too much might
-# cause excessive overhead in clock interrupt processing,
-# potentially causing ticks to be missed and thus actually reducing
-# the accuracy of operation.
+# default value (1000 on most architectures) means a granularity of 1ms
+# (1s/HZ).  Historically, the default was 100, but finer granularity is
+# required for DUMMYNET and other systems on modern hardware.  There are
+# reasonable arguments that HZ should, in fact, be 100 still; consider,
+# that reducing the granularity too much might cause excessive overhead in
+# clock interrupt processing, potentially causing ticks to be missed and thus
+# actually reducing the accuracy of operation.
 
 options 	HZ=100