1#!/bin/bash
2#
3# Script for max single flow performance
4#  - If correctly tuned[1], single CPU 10G wirespeed small pkts is possible[2]
5#
6# Using pktgen "burst" option (use -b $N)
7#  - To boost max performance
8#  - Avail since: kernel v3.18
9#   * commit 38b2cf2982dc73 ("net: pktgen: packet bursting via skb->xmit_more")
10#  - This avoids writing the HW tailptr on every driver xmit
11#  - The performance boost is impressive, see commit and blog [2]
12#
13# Notice: On purpose generates a single (UDP) flow towards target,
14#   reason behind this is to only overload/activate a single CPU on
15#   target host.  And no randomness for pktgen also makes it faster.
16#
17# Tuning see:
18#  [1] http://netoptimizer.blogspot.dk/2014/06/pktgen-for-network-overload-testing.html
19#  [2] http://netoptimizer.blogspot.dk/2014/10/unlocked-10gbps-tx-wirespeed-smallest.html
20#
21basedir=`dirname $0`
22source ${basedir}/functions.sh
23root_check_run_with_sudo "$@"
24
25# Parameter parsing via include
26source ${basedir}/parameters.sh
27# Set some default params, if they didn't get set
28[ -z "$DEST_IP" ]   && DEST_IP="198.18.0.42"
29[ -z "$DST_MAC" ]   && DST_MAC="90:e2:ba:ff:ff:ff"
30[ -z "$BURST" ]     && BURST=32
31[ -z "$CLONE_SKB" ] && CLONE_SKB="100000"
32
33# Base Config
34DELAY="0"  # Zero means max speed
35COUNT="0"  # Zero means indefinitely
36
37# General cleanup everything since last run
38pg_ctrl "reset"
39
40# Threads are specified with parameter -t value in $THREADS
41for ((thread = 0; thread < $THREADS; thread++)); do
42    dev=${DEV}@${thread}
43
44    # Add remove all other devices and add_device $dev to thread
45    pg_thread $thread "rem_device_all"
46    pg_thread $thread "add_device" $dev
47
48    # Base config
49    pg_set $dev "flag QUEUE_MAP_CPU"
50    pg_set $dev "count $COUNT"
51    pg_set $dev "clone_skb $CLONE_SKB"
52    pg_set $dev "pkt_size $PKT_SIZE"
53    pg_set $dev "delay $DELAY"
54    pg_set $dev "flag NO_TIMESTAMP"
55
56    # Destination
57    pg_set $dev "dst_mac $DST_MAC"
58    pg_set $dev "dst $DEST_IP"
59
60    # Setup burst, for easy testing -b 0 disable bursting
61    # (internally in pktgen default and minimum burst=1)
62    if [[ ${BURST} -ne 0 ]]; then
63	pg_set $dev "burst $BURST"
64    else
65	info "$dev: Not using burst"
66    fi
67done
68
69# Run if user hits control-c
70function control_c() {
71    # Print results
72    for ((thread = 0; thread < $THREADS; thread++)); do
73	dev=${DEV}@${thread}
74	echo "Device: $dev"
75	cat /proc/net/pktgen/$dev | grep -A2 "Result:"
76    done
77}
78# trap keyboard interrupt (Ctrl-C)
79trap control_c SIGINT
80
81echo "Running... ctrl^C to stop" >&2
82pg_ctrl "start"
83