From: Petr Machata <petrm@mellanox.com>
Date: Tue, 30 Jun 2020 10:14:51 +0000 (+0300)
Subject: man: tc: Describe qevents
X-Git-Tag: v5.9.0~35^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3cf51fb3c86f330c71e762b8b48cfdc3ffbb3e3c;p=thirdparty%2Fiproute2.git

man: tc: Describe qevents

Add some general remarks about qevents.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
---

diff --git a/man/man8/tc.8 b/man/man8/tc.8
index e8e0cd0fe..eba73dbff 100644
--- a/man/man8/tc.8
+++ b/man/man8/tc.8
@@ -254,6 +254,25 @@ Traffic control filter that matches every packet. See
 .BR tc-matchall (8)
 for details.
 
+.SH QEVENTS
+Qdiscs may invoke user-configured actions when certain interesting events
+take place in the qdisc. Each qevent can either be unused, or can have a
+block attached to it. To this block are then attached filters using the "tc
+block BLOCK_IDX" syntax. The block is executed when the qevent associated
+with the attachment point takes place. For example, packet could be
+dropped, or delayed, etc., depending on the qdisc and the qevent in
+question.
+
+For example:
+.PP
+.RS
+tc qdisc add dev eth0 root handle 1: red limit 500K avpkt 1K \\
+   qevent early_drop block 10
+.RE
+.RS
+tc filter add block 10 matchall action mirred egress mirror dev eth1
+.RE
+
 .SH CLASSLESS QDISCS
 The classless qdiscs are:
 .TP