net_sched: gred: add TCA_GRED_LIMIT attribute
[deliverable/linux.git] / Documentation / networking / pktgen.txt
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1
2
3 HOWTO for the linux packet generator
4 ------------------------------------
5
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6Enable CONFIG_NET_PKTGEN to compile and build pktgen either in-kernel
7or as a module. A module is preferred; modprobe pktgen if needed. Once
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8running, pktgen creates a thread for each CPU with affinity to that CPU.
9Monitoring and controlling is done via /proc. It is easiest to select a
10suitable sample script and configure that.
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11
12On a dual CPU:
13
14ps aux | grep pkt
15root 129 0.3 0.0 0 0 ? SW 2003 523:20 [pktgen/0]
16root 130 0.3 0.0 0 0 ? SW 2003 509:50 [pktgen/1]
17
18
2fe0ae78 19For monitoring and control pktgen creates:
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20 /proc/net/pktgen/pgctrl
21 /proc/net/pktgen/kpktgend_X
22 /proc/net/pktgen/ethX
23
24
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25Tuning NIC for max performance
26==============================
27
ca5b542c 28The default NIC settings are (likely) not tuned for pktgen's artificial
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29overload type of benchmarking, as this could hurt the normal use-case.
30
31Specifically increasing the TX ring buffer in the NIC:
32 # ethtool -G ethX tx 1024
33
34A larger TX ring can improve pktgen's performance, while it can hurt
35in the general case, 1) because the TX ring buffer might get larger
ca5b542c 36than the CPU's L1/L2 cache, 2) because it allows more queueing in the
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37NIC HW layer (which is bad for bufferbloat).
38
ca5b542c 39One should hesitate to conclude that packets/descriptors in the HW
9ceb87fc 40TX ring cause delay. Drivers usually delay cleaning up the
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41ring-buffers for various performance reasons, and packets stalling
42the TX ring might just be waiting for cleanup.
9ceb87fc 43
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44This cleanup issue is specifically the case for the driver ixgbe
45(Intel 82599 chip). This driver (ixgbe) combines TX+RX ring cleanups,
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46and the cleanup interval is affected by the ethtool --coalesce setting
47of parameter "rx-usecs".
48
ca5b542c 49For ixgbe use e.g. "30" resulting in approx 33K interrupts/sec (1/30*10^6):
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50 # ethtool -C ethX rx-usecs 30
51
52
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53Viewing threads
54===============
55/proc/net/pktgen/kpktgend_0
56Name: kpktgend_0 max_before_softirq: 10000
57Running:
58Stopped: eth1
59Result: OK: max_before_softirq=10000
60
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61Most important are the devices assigned to the thread. Note that a
62device can only belong to one thread.
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63
64
65Viewing devices
66===============
67
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68The Params section holds configured information. The Current section
69holds running statistics. The Result is printed after a run or after
70interruption. Example:
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71
72/proc/net/pktgen/eth1
73
74Params: count 10000000 min_pkt_size: 60 max_pkt_size: 60
75 frags: 0 delay: 0 clone_skb: 1000000 ifname: eth1
76 flows: 0 flowlen: 0
77 dst_min: 10.10.11.2 dst_max:
78 src_min: src_max:
79 src_mac: 00:00:00:00:00:00 dst_mac: 00:04:23:AC:FD:82
80 udp_src_min: 9 udp_src_max: 9 udp_dst_min: 9 udp_dst_max: 9
81 src_mac_count: 0 dst_mac_count: 0
82 Flags:
83Current:
84 pkts-sofar: 10000000 errors: 39664
85 started: 1103053986245187us stopped: 1103053999346329us idle: 880401us
86 seq_num: 10000011 cur_dst_mac_offset: 0 cur_src_mac_offset: 0
87 cur_saddr: 0x10a0a0a cur_daddr: 0x20b0a0a
88 cur_udp_dst: 9 cur_udp_src: 9
89 flows: 0
90Result: OK: 13101142(c12220741+d880401) usec, 10000000 (60byte,0frags)
91 763292pps 390Mb/sec (390805504bps) errors: 39664
92
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93Configuring threads and devices
94================================
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95This is done via the /proc interface, and most easily done via pgset
96as defined in the sample scripts.
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97
98Examples:
99
100 pgset "clone_skb 1" sets the number of copies of the same packet
101 pgset "clone_skb 0" use single SKB for all transmits
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102 pgset "burst 8" uses xmit_more API to queue 8 copies of the same
103 packet and update HW tx queue tail pointer once.
104 "burst 1" is the default
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105 pgset "pkt_size 9014" sets packet size to 9014
106 pgset "frags 5" packet will consist of 5 fragments
107 pgset "count 200000" sets number of packets to send, set to zero
d0f19d82 108 for continuous sends until explicitly stopped.
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109
110 pgset "delay 5000" adds delay to hard_start_xmit(). nanoseconds
111
112 pgset "dst 10.0.0.1" sets IP destination address
113 (BEWARE! This generator is very aggressive!)
114
115 pgset "dst_min 10.0.0.1" Same as dst
116 pgset "dst_max 10.0.0.254" Set the maximum destination IP.
117 pgset "src_min 10.0.0.1" Set the minimum (or only) source IP.
118 pgset "src_max 10.0.0.254" Set the maximum source IP.
119 pgset "dst6 fec0::1" IPV6 destination address
120 pgset "src6 fec0::2" IPV6 source address
121 pgset "dstmac 00:00:00:00:00:00" sets MAC destination address
122 pgset "srcmac 00:00:00:00:00:00" sets MAC source address
123
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124 pgset "queue_map_min 0" Sets the min value of tx queue interval
125 pgset "queue_map_max 7" Sets the max value of tx queue interval, for multiqueue devices
126 To select queue 1 of a given device,
127 use queue_map_min=1 and queue_map_max=1
128
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129 pgset "src_mac_count 1" Sets the number of MACs we'll range through.
130 The 'minimum' MAC is what you set with srcmac.
131
132 pgset "dst_mac_count 1" Sets the number of MACs we'll range through.
133 The 'minimum' MAC is what you set with dstmac.
134
135 pgset "flag [name]" Set a flag to determine behaviour. Current flags
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136 are: IPSRC_RND # IP source is random (between min/max)
137 IPDST_RND # IP destination is random
138 UDPSRC_RND, UDPDST_RND,
139 MACSRC_RND, MACDST_RND
140 TXSIZE_RND, IPV6,
f0e82fd0 141 MPLS_RND, VID_RND, SVID_RND
72f8e06f 142 FLOW_SEQ,
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143 QUEUE_MAP_RND # queue map random
144 QUEUE_MAP_CPU # queue map mirrors smp_processor_id()
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145 UDPCSUM,
146 IPSEC # IPsec encapsulation (needs CONFIG_XFRM)
147 NODE_ALLOC # node specific memory allocation
f1f00d8f 148 NO_TIMESTAMP # disable timestamping
896a7cf8 149
e5f79d11 150 pgset spi SPI_VALUE Set specific SA used to transform packet.
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151
152 pgset "udp_src_min 9" set UDP source port min, If < udp_src_max, then
153 cycle through the port range.
154
155 pgset "udp_src_max 9" set UDP source port max.
156 pgset "udp_dst_min 9" set UDP destination port min, If < udp_dst_max, then
157 cycle through the port range.
158 pgset "udp_dst_max 9" set UDP destination port max.
159
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160 pgset "mpls 0001000a,0002000a,0000000a" set MPLS labels (in this example
161 outer label=16,middle label=32,
162 inner label=0 (IPv4 NULL)) Note that
163 there must be no spaces between the
164 arguments. Leading zeros are required.
165 Do not set the bottom of stack bit,
fa00e7e1 166 that's done automatically. If you do
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167 set the bottom of stack bit, that
168 indicates that you want to randomly
169 generate that address and the flag
170 MPLS_RND will be turned on. You
171 can have any mix of random and fixed
172 labels in the label stack.
173
174 pgset "mpls 0" turn off mpls (or any invalid argument works too!)
175
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176 pgset "vlan_id 77" set VLAN ID 0-4095
177 pgset "vlan_p 3" set priority bit 0-7 (default 0)
178 pgset "vlan_cfi 0" set canonical format identifier 0-1 (default 0)
179
180 pgset "svlan_id 22" set SVLAN ID 0-4095
181 pgset "svlan_p 3" set priority bit 0-7 (default 0)
182 pgset "svlan_cfi 0" set canonical format identifier 0-1 (default 0)
183
184 pgset "vlan_id 9999" > 4095 remove vlan and svlan tags
185 pgset "svlan 9999" > 4095 remove svlan tag
186
187
188 pgset "tos XX" set former IPv4 TOS field (e.g. "tos 28" for AF11 no ECN, default 00)
189 pgset "traffic_class XX" set former IPv6 TRAFFIC CLASS (e.g. "traffic_class B8" for EF no ECN, default 00)
190
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191 pgset stop aborts injection. Also, ^C aborts generator.
192
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193 pgset "rate 300M" set rate to 300 Mb/s
194 pgset "ratep 1000000" set rate to 1Mpps
1da177e4 195
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196 pgset "xmit_mode netif_receive" RX inject into stack netif_receive_skb()
197 Works with "burst" but not with "clone_skb".
198 Default xmit_mode is "start_xmit".
199
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200Sample scripts
201==============
1da177e4 202
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203A collection of small tutorial scripts for pktgen is in the
204samples/pktgen directory:
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205
206pktgen.conf-1-1 # 1 CPU 1 dev
207pktgen.conf-1-2 # 1 CPU 2 dev
208pktgen.conf-2-1 # 2 CPU's 1 dev
209pktgen.conf-2-2 # 2 CPU's 2 dev
210pktgen.conf-1-1-rdos # 1 CPU 1 dev w. route DoS
211pktgen.conf-1-1-ip6 # 1 CPU 1 dev ipv6
212pktgen.conf-1-1-ip6-rdos # 1 CPU 1 dev ipv6 w. route DoS
213pktgen.conf-1-1-flows # 1 CPU 1 dev multiple flows.
214
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215Run in shell: ./pktgen.conf-X-Y
216This does all the setup including sending.
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217
218
219Interrupt affinity
220===================
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221Note that when adding devices to a specific CPU it is a good idea to
222also assign /proc/irq/XX/smp_affinity so that the TX interrupts are bound
223to the same CPU. This reduces cache bouncing when freeing skbs.
1da177e4 224
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225Enable IPsec
226============
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227Default IPsec transformation with ESP encapsulation plus transport mode
228can be enabled by simply setting:
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229
230pgset "flag IPSEC"
231pgset "flows 1"
232
233To avoid breaking existing testbed scripts for using AH type and tunnel mode,
ca5b542c 234you can use "pgset spi SPI_VALUE" to specify which transformation mode
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235to employ.
236
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237
238Current commands and configuration options
239==========================================
240
241** Pgcontrol commands:
242
243start
244stop
245
246** Thread commands:
247
248add_device
249rem_device_all
250max_before_softirq
251
252
253** Device commands:
254
255count
256clone_skb
257debug
258
259frags
260delay
261
262src_mac_count
263dst_mac_count
264
265pkt_size
266min_pkt_size
267max_pkt_size
268
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269mpls
270
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271udp_src_min
272udp_src_max
273
274udp_dst_min
275udp_dst_max
276
277flag
278 IPSRC_RND
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279 IPDST_RND
280 UDPSRC_RND
281 UDPDST_RND
282 MACSRC_RND
283 MACDST_RND
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284 TXSIZE_RND
285 IPV6
286 MPLS_RND
287 VID_RND
288 SVID_RND
289 FLOW_SEQ
290 QUEUE_MAP_RND
291 QUEUE_MAP_CPU
292 UDPCSUM
e5f79d11 293 IPSEC
72f8e06f 294 NODE_ALLOC
f1f00d8f 295 NO_TIMESTAMP
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296
297dst_min
298dst_max
299
300src_min
301src_max
302
303dst_mac
304src_mac
305
306clear_counters
307
308dst6
309src6
310
311flows
312flowlen
313
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314rate
315ratep
316
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317xmit_mode <start_xmit|netif_receive>
318
319
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320References:
321ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/
322ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/examples/
323
324Paper from Linux-Kongress in Erlangen 2004.
325ftp://robur.slu.se/pub/Linux/net-development/pktgen-testing/pktgen_paper.pdf
326
327Thanks to:
328Grant Grundler for testing on IA-64 and parisc, Harald Welte, Lennert Buytenhek
329Stephen Hemminger, Andi Kleen, Dave Miller and many others.
330
331
ca6549af 332Good luck with the linux net-development.
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