mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
412 lines
12 KiB
412 lines
12 KiB
.. SPDX-License-Identifier: GPL-2.0 |
|
|
|
==================================== |
|
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/ |
|
- tp://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.
|
|
|