From 6bfb1788b2986d5d2dde9bc6dd941234c2076ae5 Mon Sep 17 00:00:00 2001
From: Phil Sutter <psutter@redhat.com>
Date: Wed, 30 Mar 2016 16:51:09 +0200
Subject: [PATCH] man: tc-police.8: Emphasize on the two rate control
 mechanisms

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1275426
Upstream Status: iproute2.git commit 8409abd59bbc8

commit 8409abd59bbc8a79689be25ab3a385c65d1334bd
Author: Phil Sutter <phil@nwl.cc>
Date:   Tue Mar 22 15:48:36 2016 +0100

    man: tc-police.8: Emphasize on the two rate control mechanisms

    As Jamal pointed out, there are two different approaches to bandwidth
    measurement. Try to make this clear by separating them in synopsis and
    also documenting the way to fine-tune avrate.

    Signed-off-by: Phil Sutter <phil@nwl.cc>
    Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 man/man8/tc-police.8 | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/man/man8/tc-police.8 b/man/man8/tc-police.8
index 2b1537e..5c5a632 100644
--- a/man/man8/tc-police.8
+++ b/man/man8/tc-police.8
@@ -12,13 +12,21 @@ police - policing action
 .IR BYTES [\fB/ BYTES "] ] ["
 .BI peakrate " RATE"
 ] [
-.BI avrate " RATE"
-] [
 .BI overhead " BYTES"
 ] [
 .BI linklayer " TYPE"
 ] [
-.BI conform-exceed " EXCEEDACT\fR[\fB/\fIEXCEEDACT\fR]"
+.IR CONTROL " ]"
+
+.ti -8
+.BR tc " ... " filter " ... [ " estimator
+.IR "SAMPLE AVERAGE " ]
+.BR "action police avrate"
+.IR RATE " [ " CONTROL " ]"
+
+.ti -8
+.IR CONTROL " :="
+.BI conform-exceed " EXCEEDACT\fR[\fB/\fIEXCEEDACT"
 
 .ti -8
 .IR EXCEEDACT " := { "
@@ -27,7 +35,14 @@ police - policing action
 The
 .B police
 action allows to limit bandwidth of traffic matched by the filter it is
-attached to.
+attached to. Basically there are two different algorithms available to measure
+the packet rate: The first one uses an internal dual token bucket and is
+configured using the
+.BR rate ", " burst ", " mtu ", " peakrate ", " overhead " and " linklayer
+parameters. The second one uses an in-kernel sampling mechanism. It can be
+fine-tuned using the
+.B estimator
+filter parameter.
 .SH OPTIONS
 .TP
 .BI rate " RATE"
@@ -73,6 +88,12 @@ cell sizes, for
 .B ethernet
 no action is taken.
 .TP
+.BI estimator " SAMPLE AVERAGE"
+Fine-tune the in-kernel packet rate estimator.
+.IR SAMPLE " and " AVERAGE
+are time values and control the frequency in which samples are taken and over
+what timespan an average is built.
+.TP
 .BI conform-exceed " EXCEEDACT\fR[\fB/\fIEXCEEDACT\fR]"
 Define how to handle packets which exceed (and, if the second
 .I EXCEEDACT
-- 
1.8.3.1