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1da177e4 LT |
1 | |
2 | ||
d012827e | 3 | HOWTO for the linux packet generator |
1da177e4 LT |
4 | ------------------------------------ |
5 | ||
4e081e0c BH |
6 | Enable CONFIG_NET_PKTGEN to compile and build pktgen either in-kernel |
7 | or as a module. A module is preferred; modprobe pktgen if needed. Once | |
ca5b542c BH |
8 | running, pktgen creates a thread for each CPU with affinity to that CPU. |
9 | Monitoring and controlling is done via /proc. It is easiest to select a | |
10 | suitable sample script and configure that. | |
1da177e4 LT |
11 | |
12 | On a dual CPU: | |
13 | ||
14 | ps aux | grep pkt | |
d2ee7973 DS |
15 | root 129 0.3 0.0 0 0 ? SW 2003 523:20 [kpktgend_0] |
16 | root 130 0.3 0.0 0 0 ? SW 2003 509:50 [kpktgend_1] | |
1da177e4 LT |
17 | |
18 | ||
2fe0ae78 | 19 | For monitoring and control pktgen creates: |
1da177e4 LT |
20 | /proc/net/pktgen/pgctrl |
21 | /proc/net/pktgen/kpktgend_X | |
22 | /proc/net/pktgen/ethX | |
23 | ||
24 | ||
9ceb87fc JDB |
25 | Tuning NIC for max performance |
26 | ============================== | |
27 | ||
ca5b542c | 28 | The default NIC settings are (likely) not tuned for pktgen's artificial |
9ceb87fc JDB |
29 | overload type of benchmarking, as this could hurt the normal use-case. |
30 | ||
31 | Specifically increasing the TX ring buffer in the NIC: | |
32 | # ethtool -G ethX tx 1024 | |
33 | ||
34 | A larger TX ring can improve pktgen's performance, while it can hurt | |
35 | in the general case, 1) because the TX ring buffer might get larger | |
ca5b542c | 36 | than the CPU's L1/L2 cache, 2) because it allows more queueing in the |
9ceb87fc JDB |
37 | NIC HW layer (which is bad for bufferbloat). |
38 | ||
ca5b542c | 39 | One should hesitate to conclude that packets/descriptors in the HW |
9ceb87fc | 40 | TX ring cause delay. Drivers usually delay cleaning up the |
ca5b542c BH |
41 | ring-buffers for various performance reasons, and packets stalling |
42 | the TX ring might just be waiting for cleanup. | |
9ceb87fc | 43 | |
ca5b542c BH |
44 | This cleanup issue is specifically the case for the driver ixgbe |
45 | (Intel 82599 chip). This driver (ixgbe) combines TX+RX ring cleanups, | |
9ceb87fc JDB |
46 | and the cleanup interval is affected by the ethtool --coalesce setting |
47 | of parameter "rx-usecs". | |
48 | ||
ca5b542c | 49 | For ixgbe use e.g. "30" resulting in approx 33K interrupts/sec (1/30*10^6): |
9ceb87fc JDB |
50 | # ethtool -C ethX rx-usecs 30 |
51 | ||
52 | ||
2a1ddf27 JDB |
53 | Kernel threads |
54 | ============== | |
55 | Pktgen creates a thread for each CPU with affinity to that CPU. | |
56 | Which is controlled through procfile /proc/net/pktgen/kpktgend_X. | |
57 | ||
58 | Example: /proc/net/pktgen/kpktgend_0 | |
59 | ||
60 | Running: | |
61 | Stopped: eth4@0 | |
62 | Result: OK: add_device=eth4@0 | |
63 | ||
64 | Most important are the devices assigned to the thread. | |
1da177e4 | 65 | |
2a1ddf27 JDB |
66 | The two basic thread commands are: |
67 | * add_device DEVICE@NAME -- adds a single device | |
68 | * rem_device_all -- remove all associated devices | |
1da177e4 | 69 | |
edb9a1b8 | 70 | When adding a device to a thread, a corresponding procfile is created |
2a1ddf27 JDB |
71 | which is used for configuring this device. Thus, device names need to |
72 | be unique. | |
73 | ||
74 | To support adding the same device to multiple threads, which is useful | |
edb9a1b8 | 75 | with multi queue NICs, the device naming scheme is extended with "@": |
2a1ddf27 JDB |
76 | device@something |
77 | ||
78 | The part after "@" can be anything, but it is custom to use the thread | |
79 | number. | |
1da177e4 LT |
80 | |
81 | Viewing devices | |
82 | =============== | |
83 | ||
ca5b542c BH |
84 | The Params section holds configured information. The Current section |
85 | holds running statistics. The Result is printed after a run or after | |
86 | interruption. Example: | |
1da177e4 | 87 | |
2a1ddf27 | 88 | /proc/net/pktgen/eth4@0 |
1da177e4 | 89 | |
2a1ddf27 JDB |
90 | Params: count 100000 min_pkt_size: 60 max_pkt_size: 60 |
91 | frags: 0 delay: 0 clone_skb: 64 ifname: eth4@0 | |
1da177e4 | 92 | flows: 0 flowlen: 0 |
2a1ddf27 JDB |
93 | queue_map_min: 0 queue_map_max: 0 |
94 | dst_min: 192.168.81.2 dst_max: | |
95 | src_min: src_max: | |
96 | src_mac: 90:e2:ba:0a:56:b4 dst_mac: 00:1b:21:3c:9d:f8 | |
97 | udp_src_min: 9 udp_src_max: 109 udp_dst_min: 9 udp_dst_max: 9 | |
98 | src_mac_count: 0 dst_mac_count: 0 | |
99 | Flags: UDPSRC_RND NO_TIMESTAMP QUEUE_MAP_CPU | |
100 | Current: | |
101 | pkts-sofar: 100000 errors: 0 | |
102 | started: 623913381008us stopped: 623913396439us idle: 25us | |
103 | seq_num: 100001 cur_dst_mac_offset: 0 cur_src_mac_offset: 0 | |
104 | cur_saddr: 192.168.8.3 cur_daddr: 192.168.81.2 | |
105 | cur_udp_dst: 9 cur_udp_src: 42 | |
106 | cur_queue_map: 0 | |
1da177e4 | 107 | flows: 0 |
2a1ddf27 JDB |
108 | Result: OK: 15430(c15405+d25) usec, 100000 (60byte,0frags) |
109 | 6480562pps 3110Mb/sec (3110669760bps) errors: 0 | |
110 | ||
1da177e4 | 111 | |
2a1ddf27 JDB |
112 | Configuring devices |
113 | =================== | |
7c95a9d9 BH |
114 | This is done via the /proc interface, and most easily done via pgset |
115 | as defined in the sample scripts. | |
d2ee7973 DS |
116 | You need to specify PGDEV environment variable to use functions from sample |
117 | scripts, i.e.: | |
118 | export PGDEV=/proc/net/pktgen/eth4@0 | |
119 | source samples/pktgen/functions.sh | |
1da177e4 LT |
120 | |
121 | Examples: | |
122 | ||
d2ee7973 DS |
123 | pg_ctrl start starts injection. |
124 | pg_ctrl stop aborts injection. Also, ^C aborts generator. | |
125 | ||
1da177e4 LT |
126 | pgset "clone_skb 1" sets the number of copies of the same packet |
127 | pgset "clone_skb 0" use single SKB for all transmits | |
38b2cf29 AS |
128 | pgset "burst 8" uses xmit_more API to queue 8 copies of the same |
129 | packet and update HW tx queue tail pointer once. | |
130 | "burst 1" is the default | |
1da177e4 LT |
131 | pgset "pkt_size 9014" sets packet size to 9014 |
132 | pgset "frags 5" packet will consist of 5 fragments | |
133 | pgset "count 200000" sets number of packets to send, set to zero | |
d0f19d82 | 134 | for continuous sends until explicitly stopped. |
1da177e4 LT |
135 | |
136 | pgset "delay 5000" adds delay to hard_start_xmit(). nanoseconds | |
137 | ||
138 | pgset "dst 10.0.0.1" sets IP destination address | |
139 | (BEWARE! This generator is very aggressive!) | |
140 | ||
141 | pgset "dst_min 10.0.0.1" Same as dst | |
142 | pgset "dst_max 10.0.0.254" Set the maximum destination IP. | |
143 | pgset "src_min 10.0.0.1" Set the minimum (or only) source IP. | |
144 | pgset "src_max 10.0.0.254" Set the maximum source IP. | |
145 | pgset "dst6 fec0::1" IPV6 destination address | |
146 | pgset "src6 fec0::2" IPV6 source address | |
147 | pgset "dstmac 00:00:00:00:00:00" sets MAC destination address | |
148 | pgset "srcmac 00:00:00:00:00:00" sets MAC source address | |
149 | ||
896a7cf8 ED |
150 | pgset "queue_map_min 0" Sets the min value of tx queue interval |
151 | pgset "queue_map_max 7" Sets the max value of tx queue interval, for multiqueue devices | |
152 | To select queue 1 of a given device, | |
153 | use queue_map_min=1 and queue_map_max=1 | |
154 | ||
d012827e | 155 | pgset "src_mac_count 1" Sets the number of MACs we'll range through. |
1da177e4 LT |
156 | The 'minimum' MAC is what you set with srcmac. |
157 | ||
158 | pgset "dst_mac_count 1" Sets the number of MACs we'll range through. | |
159 | The 'minimum' MAC is what you set with dstmac. | |
160 | ||
161 | pgset "flag [name]" Set a flag to determine behaviour. Current flags | |
72f8e06f MK |
162 | are: IPSRC_RND # IP source is random (between min/max) |
163 | IPDST_RND # IP destination is random | |
164 | UDPSRC_RND, UDPDST_RND, | |
165 | MACSRC_RND, MACDST_RND | |
166 | TXSIZE_RND, IPV6, | |
f0e82fd0 | 167 | MPLS_RND, VID_RND, SVID_RND |
72f8e06f | 168 | FLOW_SEQ, |
896a7cf8 ED |
169 | QUEUE_MAP_RND # queue map random |
170 | QUEUE_MAP_CPU # queue map mirrors smp_processor_id() | |
72f8e06f MK |
171 | UDPCSUM, |
172 | IPSEC # IPsec encapsulation (needs CONFIG_XFRM) | |
173 | NODE_ALLOC # node specific memory allocation | |
f1f00d8f | 174 | NO_TIMESTAMP # disable timestamping |
d2ee7973 DS |
175 | pgset 'flag ![name]' Clear a flag to determine behaviour. |
176 | Note that you might need to use single quote in | |
177 | interactive mode, so that your shell wouldn't expand | |
178 | the specified flag as a history command. | |
896a7cf8 | 179 | |
d2ee7973 | 180 | pgset "spi [SPI_VALUE]" Set specific SA used to transform packet. |
1da177e4 LT |
181 | |
182 | pgset "udp_src_min 9" set UDP source port min, If < udp_src_max, then | |
183 | cycle through the port range. | |
184 | ||
185 | pgset "udp_src_max 9" set UDP source port max. | |
186 | pgset "udp_dst_min 9" set UDP destination port min, If < udp_dst_max, then | |
187 | cycle through the port range. | |
188 | pgset "udp_dst_max 9" set UDP destination port max. | |
189 | ||
ca6549af SW |
190 | pgset "mpls 0001000a,0002000a,0000000a" set MPLS labels (in this example |
191 | outer label=16,middle label=32, | |
192 | inner label=0 (IPv4 NULL)) Note that | |
193 | there must be no spaces between the | |
194 | arguments. Leading zeros are required. | |
195 | Do not set the bottom of stack bit, | |
fa00e7e1 | 196 | that's done automatically. If you do |
ca6549af SW |
197 | set the bottom of stack bit, that |
198 | indicates that you want to randomly | |
199 | generate that address and the flag | |
200 | MPLS_RND will be turned on. You | |
201 | can have any mix of random and fixed | |
202 | labels in the label stack. | |
203 | ||
204 | pgset "mpls 0" turn off mpls (or any invalid argument works too!) | |
205 | ||
f0e82fd0 FF |
206 | pgset "vlan_id 77" set VLAN ID 0-4095 |
207 | pgset "vlan_p 3" set priority bit 0-7 (default 0) | |
208 | pgset "vlan_cfi 0" set canonical format identifier 0-1 (default 0) | |
209 | ||
210 | pgset "svlan_id 22" set SVLAN ID 0-4095 | |
211 | pgset "svlan_p 3" set priority bit 0-7 (default 0) | |
212 | pgset "svlan_cfi 0" set canonical format identifier 0-1 (default 0) | |
213 | ||
214 | pgset "vlan_id 9999" > 4095 remove vlan and svlan tags | |
215 | pgset "svlan 9999" > 4095 remove svlan tag | |
216 | ||
217 | ||
218 | pgset "tos XX" set former IPv4 TOS field (e.g. "tos 28" for AF11 no ECN, default 00) | |
219 | pgset "traffic_class XX" set former IPv6 TRAFFIC CLASS (e.g. "traffic_class B8" for EF no ECN, default 00) | |
220 | ||
43d28b65 DT |
221 | pgset "rate 300M" set rate to 300 Mb/s |
222 | pgset "ratep 1000000" set rate to 1Mpps | |
1da177e4 | 223 | |
62f64aed AS |
224 | pgset "xmit_mode netif_receive" RX inject into stack netif_receive_skb() |
225 | Works with "burst" but not with "clone_skb". | |
226 | Default xmit_mode is "start_xmit". | |
227 | ||
7c95a9d9 BH |
228 | Sample scripts |
229 | ============== | |
1da177e4 | 230 | |
6f094797 JDB |
231 | A collection of tutorial scripts and helpers for pktgen is in the |
232 | samples/pktgen directory. The helper parameters.sh file support easy | |
edb9a1b8 | 233 | and consistent parameter parsing across the sample scripts. |
6f094797 JDB |
234 | |
235 | Usage example and help: | |
236 | ./pktgen_sample01_simple.sh -i eth4 -m 00:1B:21:3C:9D:F8 -d 192.168.8.2 | |
237 | ||
238 | Usage: ./pktgen_sample01_simple.sh [-vx] -i ethX | |
239 | -i : ($DEV) output interface/device (required) | |
240 | -s : ($PKT_SIZE) packet size | |
241 | -d : ($DEST_IP) destination IP | |
242 | -m : ($DST_MAC) destination MAC-addr | |
243 | -t : ($THREADS) threads to start | |
244 | -c : ($SKB_CLONE) SKB clones send before alloc new SKB | |
245 | -b : ($BURST) HW level bursting of SKBs | |
246 | -v : ($VERBOSE) verbose | |
247 | -x : ($DEBUG) debug | |
248 | ||
249 | The global variables being set are also listed. E.g. the required | |
250 | interface/device parameter "-i" sets variable $DEV. Copy the | |
251 | pktgen_sampleXX scripts and modify them to fit your own needs. | |
252 | ||
253 | The old scripts: | |
1da177e4 | 254 | |
1da177e4 | 255 | pktgen.conf-1-2 # 1 CPU 2 dev |
1da177e4 LT |
256 | pktgen.conf-1-1-rdos # 1 CPU 1 dev w. route DoS |
257 | pktgen.conf-1-1-ip6 # 1 CPU 1 dev ipv6 | |
258 | pktgen.conf-1-1-ip6-rdos # 1 CPU 1 dev ipv6 w. route DoS | |
259 | pktgen.conf-1-1-flows # 1 CPU 1 dev multiple flows. | |
260 | ||
1da177e4 LT |
261 | |
262 | Interrupt affinity | |
263 | =================== | |
ca5b542c BH |
264 | Note that when adding devices to a specific CPU it is a good idea to |
265 | also assign /proc/irq/XX/smp_affinity so that the TX interrupts are bound | |
266 | to the same CPU. This reduces cache bouncing when freeing skbs. | |
1da177e4 | 267 | |
2a1ddf27 JDB |
268 | Plus using the device flag QUEUE_MAP_CPU, which maps the SKBs TX queue |
269 | to the running threads CPU (directly from smp_processor_id()). | |
270 | ||
e5f79d11 FD |
271 | Enable IPsec |
272 | ============ | |
ca5b542c BH |
273 | Default IPsec transformation with ESP encapsulation plus transport mode |
274 | can be enabled by simply setting: | |
e5f79d11 FD |
275 | |
276 | pgset "flag IPSEC" | |
277 | pgset "flows 1" | |
278 | ||
279 | To avoid breaking existing testbed scripts for using AH type and tunnel mode, | |
ca5b542c | 280 | you can use "pgset spi SPI_VALUE" to specify which transformation mode |
e5f79d11 FD |
281 | to employ. |
282 | ||
1da177e4 LT |
283 | |
284 | Current commands and configuration options | |
285 | ========================================== | |
286 | ||
287 | ** Pgcontrol commands: | |
288 | ||
289 | start | |
290 | stop | |
91db4b3c | 291 | reset |
1da177e4 LT |
292 | |
293 | ** Thread commands: | |
294 | ||
295 | add_device | |
296 | rem_device_all | |
1da177e4 LT |
297 | |
298 | ||
299 | ** Device commands: | |
300 | ||
301 | count | |
302 | clone_skb | |
91db4b3c | 303 | burst |
1da177e4 LT |
304 | debug |
305 | ||
306 | frags | |
307 | delay | |
308 | ||
309 | src_mac_count | |
310 | dst_mac_count | |
311 | ||
d012827e | 312 | pkt_size |
1da177e4 LT |
313 | min_pkt_size |
314 | max_pkt_size | |
315 | ||
91db4b3c JDB |
316 | queue_map_min |
317 | queue_map_max | |
318 | skb_priority | |
319 | ||
320 | tos (ipv4) | |
321 | traffic_class (ipv6) | |
322 | ||
ca6549af SW |
323 | mpls |
324 | ||
1da177e4 LT |
325 | udp_src_min |
326 | udp_src_max | |
327 | ||
328 | udp_dst_min | |
329 | udp_dst_max | |
330 | ||
91db4b3c JDB |
331 | node |
332 | ||
1da177e4 LT |
333 | flag |
334 | IPSRC_RND | |
1da177e4 LT |
335 | IPDST_RND |
336 | UDPSRC_RND | |
337 | UDPDST_RND | |
338 | MACSRC_RND | |
339 | MACDST_RND | |
72f8e06f MK |
340 | TXSIZE_RND |
341 | IPV6 | |
342 | MPLS_RND | |
343 | VID_RND | |
344 | SVID_RND | |
345 | FLOW_SEQ | |
346 | QUEUE_MAP_RND | |
347 | QUEUE_MAP_CPU | |
348 | UDPCSUM | |
e5f79d11 | 349 | IPSEC |
72f8e06f | 350 | NODE_ALLOC |
f1f00d8f | 351 | NO_TIMESTAMP |
1da177e4 | 352 | |
91db4b3c JDB |
353 | spi (ipsec) |
354 | ||
1da177e4 LT |
355 | dst_min |
356 | dst_max | |
357 | ||
358 | src_min | |
359 | src_max | |
360 | ||
361 | dst_mac | |
362 | src_mac | |
363 | ||
364 | clear_counters | |
365 | ||
1da177e4 | 366 | src6 |
91db4b3c JDB |
367 | dst6 |
368 | dst6_max | |
369 | dst6_min | |
1da177e4 LT |
370 | |
371 | flows | |
372 | flowlen | |
373 | ||
43d28b65 DT |
374 | rate |
375 | ratep | |
376 | ||
62f64aed AS |
377 | xmit_mode <start_xmit|netif_receive> |
378 | ||
91db4b3c JDB |
379 | vlan_cfi |
380 | vlan_id | |
381 | vlan_p | |
382 | ||
383 | svlan_cfi | |
384 | svlan_id | |
385 | svlan_p | |
386 | ||
62f64aed | 387 | |
1da177e4 LT |
388 | References: |
389 | ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/ | |
390 | ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/ | |
391 | ||
392 | Paper from Linux-Kongress in Erlangen 2004. | |
393 | ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/pktgen_paper.pdf | |
394 | ||
395 | Thanks to: | |
396 | Grant Grundler for testing on IA-64 and parisc, Harald Welte, Lennert Buytenhek | |
397 | Stephen Hemminger, Andi Kleen, Dave Miller and many others. | |
398 | ||
399 | ||
ca6549af | 400 | Good luck with the linux net-development. |