401 lines
12 KiB
Plaintext
401 lines
12 KiB
Plaintext
|
|
|
|
HOWTO for the linux packet generator
|
|
------------------------------------
|
|
|
|
Enable CONFIG_NET_PKTGEN to compile and build pktgen either in-kernel
|
|
or as a module. A module is preferred; modprobe pktgen if needed. Once
|
|
running, pktgen creates a thread for each CPU with affinity to that CPU.
|
|
Monitoring and controlling is done via /proc. It is easiest to select a
|
|
suitable sample script and configure that.
|
|
|
|
On a dual CPU:
|
|
|
|
ps aux | grep pkt
|
|
root 129 0.3 0.0 0 0 ? SW 2003 523:20 [kpktgend_0]
|
|
root 130 0.3 0.0 0 0 ? SW 2003 509:50 [kpktgend_1]
|
|
|
|
|
|
For monitoring and control pktgen creates:
|
|
/proc/net/pktgen/pgctrl
|
|
/proc/net/pktgen/kpktgend_X
|
|
/proc/net/pktgen/ethX
|
|
|
|
|
|
Tuning NIC for max performance
|
|
==============================
|
|
|
|
The default NIC settings are (likely) not tuned for pktgen's artificial
|
|
overload type of benchmarking, as this could hurt the normal use-case.
|
|
|
|
Specifically increasing the TX ring buffer in the NIC:
|
|
# ethtool -G ethX tx 1024
|
|
|
|
A larger TX ring can improve pktgen's performance, while it can hurt
|
|
in the general case, 1) because the TX ring buffer might get larger
|
|
than the CPU's L1/L2 cache, 2) because it allows more queueing in the
|
|
NIC HW layer (which is bad for bufferbloat).
|
|
|
|
One should hesitate to conclude that packets/descriptors in the HW
|
|
TX ring cause delay. Drivers usually delay cleaning up the
|
|
ring-buffers for various performance reasons, and packets stalling
|
|
the TX ring might just be waiting for cleanup.
|
|
|
|
This cleanup issue is specifically the case for the driver ixgbe
|
|
(Intel 82599 chip). This driver (ixgbe) combines TX+RX ring cleanups,
|
|
and the cleanup interval is affected by the ethtool --coalesce setting
|
|
of parameter "rx-usecs".
|
|
|
|
For ixgbe use e.g. "30" resulting in approx 33K interrupts/sec (1/30*10^6):
|
|
# ethtool -C ethX rx-usecs 30
|
|
|
|
|
|
Kernel threads
|
|
==============
|
|
Pktgen creates a thread for each CPU with affinity to that CPU.
|
|
Which is controlled through procfile /proc/net/pktgen/kpktgend_X.
|
|
|
|
Example: /proc/net/pktgen/kpktgend_0
|
|
|
|
Running:
|
|
Stopped: eth4@0
|
|
Result: OK: add_device=eth4@0
|
|
|
|
Most important are the devices assigned to the thread.
|
|
|
|
The two basic thread commands are:
|
|
* add_device DEVICE@NAME -- adds a single device
|
|
* rem_device_all -- remove all associated devices
|
|
|
|
When adding a device to a thread, a corresponding procfile is created
|
|
which is used for configuring this device. Thus, device names need to
|
|
be unique.
|
|
|
|
To support adding the same device to multiple threads, which is useful
|
|
with multi queue NICs, the device naming scheme is extended with "@":
|
|
device@something
|
|
|
|
The part after "@" can be anything, but it is custom to use the thread
|
|
number.
|
|
|
|
Viewing devices
|
|
===============
|
|
|
|
The Params section holds configured information. The Current section
|
|
holds running statistics. The Result is printed after a run or after
|
|
interruption. Example:
|
|
|
|
/proc/net/pktgen/eth4@0
|
|
|
|
Params: count 100000 min_pkt_size: 60 max_pkt_size: 60
|
|
frags: 0 delay: 0 clone_skb: 64 ifname: eth4@0
|
|
flows: 0 flowlen: 0
|
|
queue_map_min: 0 queue_map_max: 0
|
|
dst_min: 192.168.81.2 dst_max:
|
|
src_min: src_max:
|
|
src_mac: 90:e2:ba:0a:56:b4 dst_mac: 00:1b:21:3c:9d:f8
|
|
udp_src_min: 9 udp_src_max: 109 udp_dst_min: 9 udp_dst_max: 9
|
|
src_mac_count: 0 dst_mac_count: 0
|
|
Flags: UDPSRC_RND NO_TIMESTAMP QUEUE_MAP_CPU
|
|
Current:
|
|
pkts-sofar: 100000 errors: 0
|
|
started: 623913381008us stopped: 623913396439us idle: 25us
|
|
seq_num: 100001 cur_dst_mac_offset: 0 cur_src_mac_offset: 0
|
|
cur_saddr: 192.168.8.3 cur_daddr: 192.168.81.2
|
|
cur_udp_dst: 9 cur_udp_src: 42
|
|
cur_queue_map: 0
|
|
flows: 0
|
|
Result: OK: 15430(c15405+d25) usec, 100000 (60byte,0frags)
|
|
6480562pps 3110Mb/sec (3110669760bps) errors: 0
|
|
|
|
|
|
Configuring devices
|
|
===================
|
|
This is done via the /proc interface, and most easily done via pgset
|
|
as defined in the sample scripts.
|
|
You need to specify PGDEV environment variable to use functions from sample
|
|
scripts, i.e.:
|
|
export PGDEV=/proc/net/pktgen/eth4@0
|
|
source samples/pktgen/functions.sh
|
|
|
|
Examples:
|
|
|
|
pg_ctrl start starts injection.
|
|
pg_ctrl stop aborts injection. Also, ^C aborts generator.
|
|
|
|
pgset "clone_skb 1" sets the number of copies of the same packet
|
|
pgset "clone_skb 0" use single SKB for all transmits
|
|
pgset "burst 8" uses xmit_more API to queue 8 copies of the same
|
|
packet and update HW tx queue tail pointer once.
|
|
"burst 1" is the default
|
|
pgset "pkt_size 9014" sets packet size to 9014
|
|
pgset "frags 5" packet will consist of 5 fragments
|
|
pgset "count 200000" sets number of packets to send, set to zero
|
|
for continuous sends until explicitly stopped.
|
|
|
|
pgset "delay 5000" adds delay to hard_start_xmit(). nanoseconds
|
|
|
|
pgset "dst 10.0.0.1" sets IP destination address
|
|
(BEWARE! This generator is very aggressive!)
|
|
|
|
pgset "dst_min 10.0.0.1" Same as dst
|
|
pgset "dst_max 10.0.0.254" Set the maximum destination IP.
|
|
pgset "src_min 10.0.0.1" Set the minimum (or only) source IP.
|
|
pgset "src_max 10.0.0.254" Set the maximum source IP.
|
|
pgset "dst6 fec0::1" IPV6 destination address
|
|
pgset "src6 fec0::2" IPV6 source address
|
|
pgset "dstmac 00:00:00:00:00:00" sets MAC destination address
|
|
pgset "srcmac 00:00:00:00:00:00" sets MAC source address
|
|
|
|
pgset "queue_map_min 0" Sets the min value of tx queue interval
|
|
pgset "queue_map_max 7" Sets the max value of tx queue interval, for multiqueue devices
|
|
To select queue 1 of a given device,
|
|
use queue_map_min=1 and queue_map_max=1
|
|
|
|
pgset "src_mac_count 1" Sets the number of MACs we'll range through.
|
|
The 'minimum' MAC is what you set with srcmac.
|
|
|
|
pgset "dst_mac_count 1" Sets the number of MACs we'll range through.
|
|
The 'minimum' MAC is what you set with dstmac.
|
|
|
|
pgset "flag [name]" Set a flag to determine behaviour. Current flags
|
|
are: IPSRC_RND # IP source is random (between min/max)
|
|
IPDST_RND # IP destination is random
|
|
UDPSRC_RND, UDPDST_RND,
|
|
MACSRC_RND, MACDST_RND
|
|
TXSIZE_RND, IPV6,
|
|
MPLS_RND, VID_RND, SVID_RND
|
|
FLOW_SEQ,
|
|
QUEUE_MAP_RND # queue map random
|
|
QUEUE_MAP_CPU # queue map mirrors smp_processor_id()
|
|
UDPCSUM,
|
|
IPSEC # IPsec encapsulation (needs CONFIG_XFRM)
|
|
NODE_ALLOC # node specific memory allocation
|
|
NO_TIMESTAMP # disable timestamping
|
|
pgset 'flag ![name]' Clear a flag to determine behaviour.
|
|
Note that you might need to use single quote in
|
|
interactive mode, so that your shell wouldn't expand
|
|
the specified flag as a history command.
|
|
|
|
pgset "spi [SPI_VALUE]" Set specific SA used to transform packet.
|
|
|
|
pgset "udp_src_min 9" set UDP source port min, If < udp_src_max, then
|
|
cycle through the port range.
|
|
|
|
pgset "udp_src_max 9" set UDP source port max.
|
|
pgset "udp_dst_min 9" set UDP destination port min, If < udp_dst_max, then
|
|
cycle through the port range.
|
|
pgset "udp_dst_max 9" set UDP destination port max.
|
|
|
|
pgset "mpls 0001000a,0002000a,0000000a" set MPLS labels (in this example
|
|
outer label=16,middle label=32,
|
|
inner label=0 (IPv4 NULL)) Note that
|
|
there must be no spaces between the
|
|
arguments. Leading zeros are required.
|
|
Do not set the bottom of stack bit,
|
|
that's done automatically. If you do
|
|
set the bottom of stack bit, that
|
|
indicates that you want to randomly
|
|
generate that address and the flag
|
|
MPLS_RND will be turned on. You
|
|
can have any mix of random and fixed
|
|
labels in the label stack.
|
|
|
|
pgset "mpls 0" turn off mpls (or any invalid argument works too!)
|
|
|
|
pgset "vlan_id 77" set VLAN ID 0-4095
|
|
pgset "vlan_p 3" set priority bit 0-7 (default 0)
|
|
pgset "vlan_cfi 0" set canonical format identifier 0-1 (default 0)
|
|
|
|
pgset "svlan_id 22" set SVLAN ID 0-4095
|
|
pgset "svlan_p 3" set priority bit 0-7 (default 0)
|
|
pgset "svlan_cfi 0" set canonical format identifier 0-1 (default 0)
|
|
|
|
pgset "vlan_id 9999" > 4095 remove vlan and svlan tags
|
|
pgset "svlan 9999" > 4095 remove svlan tag
|
|
|
|
|
|
pgset "tos XX" set former IPv4 TOS field (e.g. "tos 28" for AF11 no ECN, default 00)
|
|
pgset "traffic_class XX" set former IPv6 TRAFFIC CLASS (e.g. "traffic_class B8" for EF no ECN, default 00)
|
|
|
|
pgset "rate 300M" set rate to 300 Mb/s
|
|
pgset "ratep 1000000" set rate to 1Mpps
|
|
|
|
pgset "xmit_mode netif_receive" RX inject into stack netif_receive_skb()
|
|
Works with "burst" but not with "clone_skb".
|
|
Default xmit_mode is "start_xmit".
|
|
|
|
Sample scripts
|
|
==============
|
|
|
|
A collection of tutorial scripts and helpers for pktgen is in the
|
|
samples/pktgen directory. The helper parameters.sh file support easy
|
|
and consistent parameter parsing across the sample scripts.
|
|
|
|
Usage example and help:
|
|
./pktgen_sample01_simple.sh -i eth4 -m 00:1B:21:3C:9D:F8 -d 192.168.8.2
|
|
|
|
Usage: ./pktgen_sample01_simple.sh [-vx] -i ethX
|
|
-i : ($DEV) output interface/device (required)
|
|
-s : ($PKT_SIZE) packet size
|
|
-d : ($DEST_IP) destination IP
|
|
-m : ($DST_MAC) destination MAC-addr
|
|
-t : ($THREADS) threads to start
|
|
-c : ($SKB_CLONE) SKB clones send before alloc new SKB
|
|
-b : ($BURST) HW level bursting of SKBs
|
|
-v : ($VERBOSE) verbose
|
|
-x : ($DEBUG) debug
|
|
|
|
The global variables being set are also listed. E.g. the required
|
|
interface/device parameter "-i" sets variable $DEV. Copy the
|
|
pktgen_sampleXX scripts and modify them to fit your own needs.
|
|
|
|
The old scripts:
|
|
|
|
pktgen.conf-1-2 # 1 CPU 2 dev
|
|
pktgen.conf-1-1-rdos # 1 CPU 1 dev w. route DoS
|
|
pktgen.conf-1-1-ip6 # 1 CPU 1 dev ipv6
|
|
pktgen.conf-1-1-ip6-rdos # 1 CPU 1 dev ipv6 w. route DoS
|
|
pktgen.conf-1-1-flows # 1 CPU 1 dev multiple flows.
|
|
|
|
|
|
Interrupt affinity
|
|
===================
|
|
Note that when adding devices to a specific CPU it is a good idea to
|
|
also assign /proc/irq/XX/smp_affinity so that the TX interrupts are bound
|
|
to the same CPU. This reduces cache bouncing when freeing skbs.
|
|
|
|
Plus using the device flag QUEUE_MAP_CPU, which maps the SKBs TX queue
|
|
to the running threads CPU (directly from smp_processor_id()).
|
|
|
|
Enable IPsec
|
|
============
|
|
Default IPsec transformation with ESP encapsulation plus transport mode
|
|
can be enabled by simply setting:
|
|
|
|
pgset "flag IPSEC"
|
|
pgset "flows 1"
|
|
|
|
To avoid breaking existing testbed scripts for using AH type and tunnel mode,
|
|
you can use "pgset spi SPI_VALUE" to specify which transformation mode
|
|
to employ.
|
|
|
|
|
|
Current commands and configuration options
|
|
==========================================
|
|
|
|
** Pgcontrol commands:
|
|
|
|
start
|
|
stop
|
|
reset
|
|
|
|
** Thread commands:
|
|
|
|
add_device
|
|
rem_device_all
|
|
|
|
|
|
** Device commands:
|
|
|
|
count
|
|
clone_skb
|
|
burst
|
|
debug
|
|
|
|
frags
|
|
delay
|
|
|
|
src_mac_count
|
|
dst_mac_count
|
|
|
|
pkt_size
|
|
min_pkt_size
|
|
max_pkt_size
|
|
|
|
queue_map_min
|
|
queue_map_max
|
|
skb_priority
|
|
|
|
tos (ipv4)
|
|
traffic_class (ipv6)
|
|
|
|
mpls
|
|
|
|
udp_src_min
|
|
udp_src_max
|
|
|
|
udp_dst_min
|
|
udp_dst_max
|
|
|
|
node
|
|
|
|
flag
|
|
IPSRC_RND
|
|
IPDST_RND
|
|
UDPSRC_RND
|
|
UDPDST_RND
|
|
MACSRC_RND
|
|
MACDST_RND
|
|
TXSIZE_RND
|
|
IPV6
|
|
MPLS_RND
|
|
VID_RND
|
|
SVID_RND
|
|
FLOW_SEQ
|
|
QUEUE_MAP_RND
|
|
QUEUE_MAP_CPU
|
|
UDPCSUM
|
|
IPSEC
|
|
NODE_ALLOC
|
|
NO_TIMESTAMP
|
|
|
|
spi (ipsec)
|
|
|
|
dst_min
|
|
dst_max
|
|
|
|
src_min
|
|
src_max
|
|
|
|
dst_mac
|
|
src_mac
|
|
|
|
clear_counters
|
|
|
|
src6
|
|
dst6
|
|
dst6_max
|
|
dst6_min
|
|
|
|
flows
|
|
flowlen
|
|
|
|
rate
|
|
ratep
|
|
|
|
xmit_mode <start_xmit|netif_receive>
|
|
|
|
vlan_cfi
|
|
vlan_id
|
|
vlan_p
|
|
|
|
svlan_cfi
|
|
svlan_id
|
|
svlan_p
|
|
|
|
|
|
References:
|
|
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/
|
|
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/
|
|
|
|
Paper from Linux-Kongress in Erlangen 2004.
|
|
ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/pktgen_paper.pdf
|
|
|
|
Thanks to:
|
|
Grant Grundler for testing on IA-64 and parisc, Harald Welte, Lennert Buytenhek
|
|
Stephen Hemminger, Andi Kleen, Dave Miller and many others.
|
|
|
|
|
|
Good luck with the linux net-development.
|