1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3#
4# Script for max single flow performance
5#  - If correctly tuned[1], single CPU 10G wirespeed small pkts is possible[2]
6#
7# Using pktgen "burst" option (use -b $N)
8#  - To boost max performance
9#  - Avail since: kernel v3.18
10#   * commit 38b2cf2982dc73 ("net: pktgen: packet bursting via skb->xmit_more")
11#  - This avoids writing the HW tailptr on every driver xmit
12#  - The performance boost is impressive, see commit and blog [2]
13#
14# Notice: On purpose generates a single (UDP) flow towards target,
15#   reason behind this is to only overload/activate a single CPU on
16#   target host.  And no randomness for pktgen also makes it faster.
17#
18# Tuning see:
19#  [1] http://netoptimizer.blogspot.dk/2014/06/pktgen-for-network-overload-testing.html
20#  [2] http://netoptimizer.blogspot.dk/2014/10/unlocked-10gbps-tx-wirespeed-smallest.html
21#
22basedir=`dirname $0`
23source ${basedir}/functions.sh
24root_check_run_with_sudo "$@"
25
26# Parameter parsing via include
27source ${basedir}/parameters.sh
28# Set some default params, if they didn't get set
29if [ -z "$DEST_IP" ]; then
30    [ -z "$IP6" ] && DEST_IP="198.18.0.42" || DEST_IP="FD00::1"
31fi
32[ -z "$DST_MAC" ]   && DST_MAC="90:e2:ba:ff:ff:ff"
33[ -z "$BURST" ]     && BURST=32
34[ -z "$CLONE_SKB" ] && CLONE_SKB="0" # No need for clones when bursting
35[ -z "$COUNT" ]     && COUNT="0" # Zero means indefinitely
36
37# Base Config
38DELAY="0"  # Zero means max speed
39
40# General cleanup everything since last run
41pg_ctrl "reset"
42
43# Threads are specified with parameter -t value in $THREADS
44for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do
45    dev=${DEV}@${thread}
46
47    # Add remove all other devices and add_device $dev to thread
48    pg_thread $thread "rem_device_all"
49    pg_thread $thread "add_device" $dev
50
51    # Base config
52    pg_set $dev "flag QUEUE_MAP_CPU"
53    pg_set $dev "count $COUNT"
54    pg_set $dev "clone_skb $CLONE_SKB"
55    pg_set $dev "pkt_size $PKT_SIZE"
56    pg_set $dev "delay $DELAY"
57    pg_set $dev "flag NO_TIMESTAMP"
58
59    # Destination
60    pg_set $dev "dst_mac $DST_MAC"
61    pg_set $dev "dst$IP6 $DEST_IP"
62
63    # Setup burst, for easy testing -b 0 disable bursting
64    # (internally in pktgen default and minimum burst=1)
65    if [[ ${BURST} -ne 0 ]]; then
66	pg_set $dev "burst $BURST"
67    else
68	info "$dev: Not using burst"
69    fi
70done
71
72# Run if user hits control-c
73function control_c() {
74    # Print results
75    for ((thread = $F_THREAD; thread <= $L_THREAD; thread++)); do
76	dev=${DEV}@${thread}
77	echo "Device: $dev"
78	cat /proc/net/pktgen/$dev | grep -A2 "Result:"
79    done
80}
81# trap keyboard interrupt (Ctrl-C)
82trap control_c SIGINT
83
84echo "Running... ctrl^C to stop" >&2
85pg_ctrl "start"
86