3 Commits

Author	SHA1	Message	Date
brakmo	71634d7f92	bpf: Add support for fq's EDT to HBM ... Adds support for fq's Earliest Departure Time to HBM (Host Bandwidth Manager). Includes a new BPF program supporting EDT, and also updates corresponding programs. It will drop packets with an EDT of more than 500us in the future unless the packet belongs to a flow with less than 2 packets in flight. This is done so each flow has at least 2 packets in flight, so they will not starve, and also to help prevent delayed ACK timeouts. It will also work with ECN enabled traffic, where the packets will be CE marked if their EDT is more than 50us in the future. The table below shows some performance numbers. The flows are back to back RPCS. One server sending to another, either 2 or 4 flows. One flow is a 10KB RPC, the rest are 1MB RPCs. When there are more than one flow of a given RPC size, the numbers represent averages. The rate limit applies to all flows (they are in the same cgroup). Tests ending with "-edt" ran with the new BPF program supporting EDT. Tests ending with "-hbt" ran on top HBT qdisc with the specified rate (i.e. no HBM). The other tests ran with the HBM BPF program included in the HBM patch-set. EDT has limited value when using DCTCP, but it helps in many cases when using Cubic. It usually achieves larger link utilization and lower 99% latencies for the 1MB RPCs. HBM ends up queueing a lot of packets with its default parameter values, reducing the goodput of the 10KB RPCs and increasing their latency. Also, the RTTs seen by the flows are quite large. Aggr 10K 10K 10K 1MB 1MB 1MB Limit rate drops RTT rate P90 P99 rate P90 P99 Test rate Flows Mbps % us Mbps us us Mbps ms ms -------- ---- ----- ---- ----- --- ---- ---- ---- ---- ---- ---- cubic 1G 2 904 0.02 108 257 511 539 647 13.4 24.5 cubic-edt 1G 2 982 0.01 156 239 656 967 743 14.0 17.2 dctcp 1G 2 977 0.00 105 324 408 744 653 14.5 15.9 dctcp-edt 1G 2 981 0.01 142 321 417 811 660 15.7 17.0 cubic-htb 1G 2 919 0.00 1825 40 2822 4140 879 9.7 9.9 cubic 200M 2 155 0.30 220 81 532 655 74 283 450 cubic-edt 200M 2 188 0.02 222 87 1035 1095 101 84 85 dctcp 200M 2 188 0.03 111 77 912 939 111 76 325 dctcp-edt 200M 2 188 0.03 217 74 1416 1738 114 76 79 cubic-htb 200M 2 188 0.00 5015 8 14ms 15ms 180 48 50 cubic 1G 4 952 0.03 110 165 516 546 262 38 154 cubic-edt 1G 4 973 0.01 190 111 1034 1314 287 65 79 dctcp 1G 4 951 0.00 103 180 617 905 257 37 38 dctcp-edt 1G 4 967 0.00 163 151 732 1126 272 43 55 cubic-htb 1G 4 914 0.00 3249 13 7ms 8ms 300 29 34 cubic 5G 4 4236 0.00 134 305 490 624 1310 10 17 cubic-edt 5G 4 4865 0.00 156 306 425 759 1520 10 16 dctcp 5G 4 4936 0.00 128 485 221 409 1484 7 9 dctcp-edt 5G 4 4924 0.00 148 390 392 623 1508 11 26 v1 -> v2: Incorporated Andrii's suggestions v2 -> v3: Incorporated Yonghong's suggestions v3 -> v4: Removed credit update that is not needed Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>	2019-07-03 15:03:00 +02:00
brakmo	ffd81558d5	bpf: Add cn support to hbm_out_kern.c ... Update hbm_out_kern.c to support returning cn notifications. Also updates relevant files to allow disabling cn notifications. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>	2019-05-31 16:41:29 -07:00
brakmo	4ffd44cfd1	bpf: HBM test script ... Script for testing HBM (Host Bandwidth Manager) framework. It creates a cgroup to use for testing and load a BPF program to limit egress bandwidht. It then uses iperf3 or netperf to create loads. The output is the goodput in Mbps (unless -D is used). It can work on a single host using loopback or among two hosts (with netperf). When using loopback, it is recommended to also introduce a delay of at least 1ms (-d=1), otherwise the assigned bandwidth is likely to be underutilized. USAGE: $name [out] [-b=<prog>|--bpf=<prog>] [-c=<cc>|--cc=<cc>] [-D] [-d=<delay>|--delay=<delay>] [--debug] [-E] [-f=<#flows>|--flows=<#flows>] [-h] [-i=<id>|--id=<id >] [-l] [-N] [-p=<port>|--port=<port>] [-P] [-q=<qdisc>] [-R] [-s=<server>|--server=<server] [--stats] [-t=<time>|--time=<time>] [-w] [cubic|dctcp] Where: out Egress (default egress) -b or --bpf BPF program filename to load and attach. Default is nrm_out_kern.o for egress, -c or -cc TCP congestion control (cubic or dctcp) -d or --delay Add a delay in ms using netem -D In addition to the goodput in Mbps, it also outputs other detailed information. This information is test dependent (i.e. iperf3 or netperf). --debug Print BPF trace buffer -E Enable ECN (not required for dctcp) -f or --flows Number of concurrent flows (default=1) -i or --id cgroup id (an integer, default is 1) -l Do not limit flows using loopback -N Use netperf instead of iperf3 -h Help -p or --port iperf3 port (default is 5201) -P Use an iperf3 instance for each flow -q Use the specified qdisc. -r or --rate Rate in Mbps (default 1s 1Gbps) -R Use TCP_RR for netperf. 1st flow has req size of 10KB, rest of 1MB. Reply in all cases is 1 byte. More detailed output for each flow can be found in the files netperf.<cg>.<flow>, where <cg> is the cgroup id as specified with the -i flag, and <flow> is the flow id starting at 1 and increasing by 1 for flow (as specified by -f). -s or --server hostname of netperf server. Used to create netperf test traffic between to hosts (default is within host) netserver must be running on the host. --stats Get HBM stats (marked, dropped, etc.) -t or --time duration of iperf3 in seconds (default=5) -w Work conserving flag. cgroup can increase its bandwidth beyond the rate limit specified while there is available bandwidth. Current implementation assumes there is only one NIC (eth0), but can be extended to support multiple NICs. This is just a proof of concept. cubic or dctcp specify TCP CC to use Examples: ./do_hbm_test.sh -l -d=1 -D --stats Runs a 5 second test, using a single iperf3 flow and with the default rate limit of 1Gbps and a delay of 1ms (using netem) using the default TCP congestion control on the loopback device (hence we use "-l" to enforce bandwidth limit on loopback device). Since no direction is specified, it defaults to egress. Since no TCP CC algorithm is specified it uses the system default (Cubic for this test). With no -D flag, only the value of the AGGREGATE OUTPUT would show. id refers to the cgroup id and is useful when running multi cgroup tests (supported by a future patch). This patchset does not support calling TCP's congesion window reduction, even when packets are dropped by the BPF program, resulting in a large number of packets dropped. It is recommended that the current HBM implemenation only be used with ECN enabled flows. A future patch will add support for reducing TCP's cwnd and will increase the performance of non-ECN enabled flows. Output: Details for HBM in cgroup 1 id:1 rate_mbps:493 duration:4.8 secs packets:11355 bytes_MB:590 pkts_dropped:4497 bytes_dropped_MB:292 pkts_marked_percent: 39.60 bytes_marked_percent: 49.49 pkts_dropped_percent: 39.60 bytes_dropped_percent: 49.49 PING AVG DELAY:2.075 AGGREGATE_GOODPUT:505 ./do_nrm_test.sh -l -d=1 -D --stats dctcp Same as above but using dctcp. Note that fewer bytes are dropped (0.01% vs. 49%). Output: Details for HBM in cgroup 1 id:1 rate_mbps:945 duration:4.9 secs packets:16859 bytes_MB:578 pkts_dropped:1 bytes_dropped_MB:0 pkts_marked_percent: 28.74 bytes_marked_percent: 45.15 pkts_dropped_percent: 0.01 bytes_dropped_percent: 0.01 PING AVG DELAY:2.083 AGGREGATE_GOODPUT:965 ./do_nrm_test.sh -d=1 -D --stats As first example, but without limiting loopback device (i.e. no "-l" flag). Since there is no bandwidth limiting, no details for HBM are printed out. Output: Details for HBM in cgroup 1 PING AVG DELAY:2.019 AGGREGATE_GOODPUT:42655 ./do_hbm.sh -l -d=1 -D --stats -f=2 Uses iper3 and does 2 flows ./do_hbm.sh -l -d=1 -D --stats -f=4 -P Uses iperf3 and does 4 flows, each flow as a separate process. ./do_hbm.sh -l -d=1 -D --stats -f=4 -N Uses netperf, 4 flows ./do_hbm.sh -f=1 -r=2000 -t=5 -N -D --stats dctcp -s=<server-name> Uses netperf between two hosts. The remote host name is specified with -s= and you need to start the program netserver manually on the remote host. It will use 1 flow, a rate limit of 2Gbps and dctcp. ./do_hbm.sh -f=1 -r=2000 -t=5 -N -D --stats -w dctcp \ -s=<server-name> As previous, but allows use of extra bandwidth. For this test the rate is 8Gbps vs. 1Gbps of the previous test. Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>	2019-03-02 10:48:27 -08:00