From: Vladimir Oltean Date: Tue, 18 Apr 2023 11:39:45 +0000 (+0300) Subject: tc/taprio: add a size table to the examples from the man page X-Git-Tag: v6.3.0~6 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=201e2f968bd2eda2dc789aa435c067499537ddf5;p=thirdparty%2Fiproute2.git tc/taprio: add a size table to the examples from the man page Since kernel commit a3d91b2c6f6b ("net/sched: taprio: warn about missing size table"), the kernel emits a warning netlink extack if the user doesn't specify a stab. We want the user be aware of the fact that the L1 overhead is determined by taprio exactly based on the overhead of the stab, so we want to encourage users to add a size table to the Qdisc. Teach them how. Signed-off-by: Vladimir Oltean Signed-off-by: Stephen Hemminger --- diff --git a/man/man8/tc-taprio.8 b/man/man8/tc-taprio.8 index 9adee7fd8..c3ccefea9 100644 --- a/man/man8/tc-taprio.8 +++ b/man/man8/tc-taprio.8 @@ -177,7 +177,7 @@ reference CLOCK_TAI. The schedule is composed of three entries each of 300us duration. .EX -# tc qdisc replace dev eth0 parent root handle 100 taprio \\ +# tc qdisc replace dev eth0 parent root handle 100 stab overhead 24 taprio \\ num_tc 3 \\ map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \\ queues 1@0 1@1 2@2 \\ @@ -193,7 +193,7 @@ Following is an example to enable the txtime offload mode in taprio. See for more information about configuring the ETF qdisc. .EX -# tc qdisc replace dev eth0 parent root handle 100 taprio \\ +# tc qdisc replace dev eth0 parent root handle 100 stab overhead 24 taprio \\ num_tc 3 \\ map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \\ queues 1@0 1@0 1@0 \\ @@ -222,10 +222,11 @@ NIC's current PTP time. In addition, the MTU for traffic class 5 is limited to 200 octets, so that the interference this creates upon traffic class 7 during the time window when their gates are both open is bounded. The interference is determined by the transmit time of the max SDU, plus the L2 header length, plus -the L1 overhead. +the L1 overhead (determined from the size table specified using +.BR tc-stab(8)). .EX -# tc qdisc add dev eth0 parent root taprio \\ +# tc qdisc add dev eth0 parent root stab overhead 24 taprio \\ num_tc 8 \\ map 0 1 2 3 4 5 6 7 \\ queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 \\ @@ -237,5 +238,8 @@ the L1 overhead. flags 0x2 .EE +.SH SEE ALSO +.BR tc-stab(8) + .SH AUTHORS Vinicius Costa Gomes