From 8409abd59bbc8a79689be25ab3a385c65d1334bd Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Tue, 22 Mar 2016 15:48:36 +0100 Subject: [PATCH] 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 Signed-off-by: Stephen Hemminger --- 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 2b1537ec..5c5a6323 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