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a1270fe9 | 1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* Copyright (c) 2019 Facebook | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of version 2 of the GNU General Public | |
6 | * License as published by the Free Software Foundation. | |
7 | * | |
8 | * Example program for Host Bandwidth Managment | |
9 | * | |
10 | * This program loads a cgroup skb BPF program to enforce cgroup output | |
11 | * (egress) or input (ingress) bandwidth limits. | |
12 | * | |
13 | * USAGE: hbm [-d] [-l] [-n <id>] [-r <rate>] [-s] [-t <secs>] [-w] [-h] [prog] | |
14 | * Where: | |
15 | * -d Print BPF trace debug buffer | |
16 | * -l Also limit flows doing loopback | |
17 | * -n <#> To create cgroup \"/hbm#\" and attach prog | |
18 | * Default is /hbm1 | |
ffd81558 | 19 | * --no_cn Do not return cn notifications |
a1270fe9 | 20 | * -r <rate> Rate limit in Mbps |
21 | * -s Get HBM stats (marked, dropped, etc.) | |
5b4f21b2 | 22 | * -t <time> Exit after specified seconds (default is 0) |
a1270fe9 | 23 | * -w Work conserving flag. cgroup can increase its bandwidth |
24 | * beyond the rate limit specified while there is available | |
25 | * bandwidth. Current implementation assumes there is only | |
26 | * NIC (eth0), but can be extended to support multiple NICs. | |
27 | * Currrently only supported for egress. | |
28 | * -h Print this info | |
29 | * prog BPF program file name. Name defaults to hbm_out_kern.o | |
30 | */ | |
31 | ||
32 | #define _GNU_SOURCE | |
33 | ||
34 | #include <stdio.h> | |
35 | #include <stdlib.h> | |
36 | #include <assert.h> | |
a1270fe9 | 37 | #include <sys/time.h> |
38 | #include <unistd.h> | |
39 | #include <errno.h> | |
40 | #include <fcntl.h> | |
41 | #include <linux/unistd.h> | |
544d6adf | 42 | #include <linux/compiler.h> |
a1270fe9 | 43 | |
44 | #include <linux/bpf.h> | |
45 | #include <bpf/bpf.h> | |
ffd81558 | 46 | #include <getopt.h> |
a1270fe9 | 47 | |
a1270fe9 | 48 | #include "cgroup_helpers.h" |
49 | #include "hbm.h" | |
50 | #include "bpf_util.h" | |
7cf245a3 | 51 | #include <bpf/libbpf.h> |
a1270fe9 | 52 | |
53 | bool outFlag = true; | |
54 | int minRate = 1000; /* cgroup rate limit in Mbps */ | |
55 | int rate = 1000; /* can grow if rate conserving is enabled */ | |
56 | int dur = 1; | |
57 | bool stats_flag; | |
58 | bool loopback_flag; | |
59 | bool debugFlag; | |
60 | bool work_conserving_flag; | |
ffd81558 | 61 | bool no_cn_flag; |
71634d7f | 62 | bool edt_flag; |
a1270fe9 | 63 | |
64 | static void Usage(void); | |
65 | static void read_trace_pipe2(void); | |
66 | static void do_error(char *msg, bool errno_flag); | |
67 | ||
68 | #define DEBUGFS "/sys/kernel/debug/tracing/" | |
69 | ||
c5815ac7 DL |
70 | static struct bpf_program *bpf_prog; |
71 | static struct bpf_object *obj; | |
72 | static int queue_stats_fd; | |
a1270fe9 | 73 | |
74 | static void read_trace_pipe2(void) | |
75 | { | |
76 | int trace_fd; | |
77 | FILE *outf; | |
78 | char *outFname = "hbm_out.log"; | |
79 | ||
80 | trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0); | |
81 | if (trace_fd < 0) { | |
82 | printf("Error opening trace_pipe\n"); | |
83 | return; | |
84 | } | |
85 | ||
86 | // Future support of ingress | |
87 | // if (!outFlag) | |
88 | // outFname = "hbm_in.log"; | |
89 | outf = fopen(outFname, "w"); | |
90 | ||
91 | if (outf == NULL) | |
92 | printf("Error creating %s\n", outFname); | |
93 | ||
94 | while (1) { | |
95 | static char buf[4097]; | |
96 | ssize_t sz; | |
97 | ||
98 | sz = read(trace_fd, buf, sizeof(buf) - 1); | |
99 | if (sz > 0) { | |
100 | buf[sz] = 0; | |
101 | puts(buf); | |
102 | if (outf != NULL) { | |
103 | fprintf(outf, "%s\n", buf); | |
104 | fflush(outf); | |
105 | } | |
106 | } | |
107 | } | |
108 | } | |
109 | ||
110 | static void do_error(char *msg, bool errno_flag) | |
111 | { | |
112 | if (errno_flag) | |
113 | printf("ERROR: %s, errno: %d\n", msg, errno); | |
114 | else | |
115 | printf("ERROR: %s\n", msg); | |
116 | exit(1); | |
117 | } | |
118 | ||
119 | static int prog_load(char *prog) | |
120 | { | |
7490d592 KFL |
121 | struct bpf_program *pos; |
122 | const char *sec_name; | |
123 | ||
c5815ac7 DL |
124 | obj = bpf_object__open_file(prog, NULL); |
125 | if (libbpf_get_error(obj)) { | |
126 | printf("ERROR: opening BPF object file failed\n"); | |
a1270fe9 | 127 | return 1; |
128 | } | |
c5815ac7 DL |
129 | |
130 | /* load BPF program */ | |
131 | if (bpf_object__load(obj)) { | |
132 | printf("ERROR: loading BPF object file failed\n"); | |
133 | goto err; | |
a1270fe9 | 134 | } |
135 | ||
7490d592 KFL |
136 | bpf_object__for_each_program(pos, obj) { |
137 | sec_name = bpf_program__section_name(pos); | |
138 | if (sec_name && !strcmp(sec_name, "cgroup_skb/egress")) { | |
139 | bpf_prog = pos; | |
140 | break; | |
141 | } | |
142 | } | |
c5815ac7 DL |
143 | if (!bpf_prog) { |
144 | printf("ERROR: finding a prog in obj file failed\n"); | |
145 | goto err; | |
a1270fe9 | 146 | } |
147 | ||
c5815ac7 DL |
148 | queue_stats_fd = bpf_object__find_map_fd_by_name(obj, "queue_stats"); |
149 | if (queue_stats_fd < 0) { | |
150 | printf("ERROR: finding a map in obj file failed\n"); | |
151 | goto err; | |
152 | } | |
153 | ||
154 | return 0; | |
155 | ||
156 | err: | |
157 | bpf_object__close(obj); | |
158 | return 1; | |
a1270fe9 | 159 | } |
160 | ||
161 | static int run_bpf_prog(char *prog, int cg_id) | |
162 | { | |
c5815ac7 DL |
163 | struct hbm_queue_stats qstats = {0}; |
164 | char cg_dir[100], cg_pin_path[100]; | |
165 | struct bpf_link *link = NULL; | |
a1270fe9 | 166 | int key = 0; |
167 | int cg1 = 0; | |
c5815ac7 | 168 | int rc = 0; |
a1270fe9 | 169 | |
170 | sprintf(cg_dir, "/hbm%d", cg_id); | |
c5815ac7 DL |
171 | rc = prog_load(prog); |
172 | if (rc != 0) | |
173 | return rc; | |
a1270fe9 | 174 | |
175 | if (setup_cgroup_environment()) { | |
176 | printf("ERROR: setting cgroup environment\n"); | |
177 | goto err; | |
178 | } | |
179 | cg1 = create_and_get_cgroup(cg_dir); | |
180 | if (!cg1) { | |
181 | printf("ERROR: create_and_get_cgroup\n"); | |
182 | goto err; | |
183 | } | |
184 | if (join_cgroup(cg_dir)) { | |
185 | printf("ERROR: join_cgroup\n"); | |
186 | goto err; | |
187 | } | |
188 | ||
189 | qstats.rate = rate; | |
190 | qstats.stats = stats_flag ? 1 : 0; | |
191 | qstats.loopback = loopback_flag ? 1 : 0; | |
ffd81558 | 192 | qstats.no_cn = no_cn_flag ? 1 : 0; |
c5815ac7 | 193 | if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY)) { |
a1270fe9 | 194 | printf("ERROR: Could not update map element\n"); |
195 | goto err; | |
196 | } | |
197 | ||
198 | if (!outFlag) | |
c5815ac7 DL |
199 | bpf_program__set_expected_attach_type(bpf_prog, BPF_CGROUP_INET_INGRESS); |
200 | ||
201 | link = bpf_program__attach_cgroup(bpf_prog, cg1); | |
202 | if (libbpf_get_error(link)) { | |
203 | fprintf(stderr, "ERROR: bpf_program__attach_cgroup failed\n"); | |
204 | goto err; | |
205 | } | |
206 | ||
207 | sprintf(cg_pin_path, "/sys/fs/bpf/hbm%d", cg_id); | |
208 | rc = bpf_link__pin(link, cg_pin_path); | |
209 | if (rc < 0) { | |
210 | printf("ERROR: bpf_link__pin failed: %d\n", rc); | |
a1270fe9 | 211 | goto err; |
212 | } | |
213 | ||
214 | if (work_conserving_flag) { | |
215 | struct timeval t0, t_last, t_new; | |
216 | FILE *fin; | |
217 | unsigned long long last_eth_tx_bytes, new_eth_tx_bytes; | |
218 | signed long long last_cg_tx_bytes, new_cg_tx_bytes; | |
219 | signed long long delta_time, delta_bytes, delta_rate; | |
220 | int delta_ms; | |
221 | #define DELTA_RATE_CHECK 10000 /* in us */ | |
222 | #define RATE_THRESHOLD 9500000000 /* 9.5 Gbps */ | |
223 | ||
c5815ac7 | 224 | bpf_map_lookup_elem(queue_stats_fd, &key, &qstats); |
a1270fe9 | 225 | if (gettimeofday(&t0, NULL) < 0) |
226 | do_error("gettimeofday failed", true); | |
227 | t_last = t0; | |
228 | fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", "r"); | |
229 | if (fscanf(fin, "%llu", &last_eth_tx_bytes) != 1) | |
230 | do_error("fscanf fails", false); | |
231 | fclose(fin); | |
232 | last_cg_tx_bytes = qstats.bytes_total; | |
233 | while (true) { | |
234 | usleep(DELTA_RATE_CHECK); | |
235 | if (gettimeofday(&t_new, NULL) < 0) | |
236 | do_error("gettimeofday failed", true); | |
237 | delta_ms = (t_new.tv_sec - t0.tv_sec) * 1000 + | |
238 | (t_new.tv_usec - t0.tv_usec)/1000; | |
239 | if (delta_ms > dur * 1000) | |
240 | break; | |
241 | delta_time = (t_new.tv_sec - t_last.tv_sec) * 1000000 + | |
242 | (t_new.tv_usec - t_last.tv_usec); | |
243 | if (delta_time == 0) | |
244 | continue; | |
245 | t_last = t_new; | |
246 | fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", | |
247 | "r"); | |
248 | if (fscanf(fin, "%llu", &new_eth_tx_bytes) != 1) | |
249 | do_error("fscanf fails", false); | |
250 | fclose(fin); | |
251 | printf(" new_eth_tx_bytes:%llu\n", | |
252 | new_eth_tx_bytes); | |
c5815ac7 | 253 | bpf_map_lookup_elem(queue_stats_fd, &key, &qstats); |
a1270fe9 | 254 | new_cg_tx_bytes = qstats.bytes_total; |
255 | delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes; | |
256 | last_eth_tx_bytes = new_eth_tx_bytes; | |
257 | delta_rate = (delta_bytes * 8000000) / delta_time; | |
258 | printf("%5d - eth_rate:%.1fGbps cg_rate:%.3fGbps", | |
259 | delta_ms, delta_rate/1000000000.0, | |
260 | rate/1000.0); | |
261 | if (delta_rate < RATE_THRESHOLD) { | |
262 | /* can increase cgroup rate limit, but first | |
263 | * check if we are using the current limit. | |
264 | * Currently increasing by 6.25%, unknown | |
265 | * if that is the optimal rate. | |
266 | */ | |
267 | int rate_diff100; | |
268 | ||
269 | delta_bytes = new_cg_tx_bytes - | |
270 | last_cg_tx_bytes; | |
271 | last_cg_tx_bytes = new_cg_tx_bytes; | |
272 | delta_rate = (delta_bytes * 8000000) / | |
273 | delta_time; | |
274 | printf(" rate:%.3fGbps", | |
275 | delta_rate/1000000000.0); | |
276 | rate_diff100 = (((long long)rate)*1000000 - | |
277 | delta_rate) * 100 / | |
278 | (((long long) rate) * 1000000); | |
279 | printf(" rdiff:%d", rate_diff100); | |
280 | if (rate_diff100 <= 3) { | |
281 | rate += (rate >> 4); | |
282 | if (rate > RATE_THRESHOLD / 1000000) | |
283 | rate = RATE_THRESHOLD / 1000000; | |
284 | qstats.rate = rate; | |
285 | printf(" INC\n"); | |
286 | } else { | |
287 | printf("\n"); | |
288 | } | |
289 | } else { | |
290 | /* Need to decrease cgroup rate limit. | |
291 | * Currently decreasing by 12.5%, unknown | |
292 | * if that is optimal | |
293 | */ | |
294 | printf(" DEC\n"); | |
295 | rate -= (rate >> 3); | |
296 | if (rate < minRate) | |
297 | rate = minRate; | |
298 | qstats.rate = rate; | |
299 | } | |
c5815ac7 | 300 | if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY)) |
a1270fe9 | 301 | do_error("update map element fails", false); |
302 | } | |
303 | } else { | |
304 | sleep(dur); | |
305 | } | |
306 | // Get stats! | |
c5815ac7 | 307 | if (stats_flag && bpf_map_lookup_elem(queue_stats_fd, &key, &qstats)) { |
a1270fe9 | 308 | char fname[100]; |
309 | FILE *fout; | |
310 | ||
311 | if (!outFlag) | |
312 | sprintf(fname, "hbm.%d.in", cg_id); | |
313 | else | |
314 | sprintf(fname, "hbm.%d.out", cg_id); | |
315 | fout = fopen(fname, "w"); | |
316 | fprintf(fout, "id:%d\n", cg_id); | |
317 | fprintf(fout, "ERROR: Could not lookup queue_stats\n"); | |
318 | } else if (stats_flag && qstats.lastPacketTime > | |
319 | qstats.firstPacketTime) { | |
320 | long long delta_us = (qstats.lastPacketTime - | |
321 | qstats.firstPacketTime)/1000; | |
322 | unsigned int rate_mbps = ((qstats.bytes_total - | |
323 | qstats.bytes_dropped) * 8 / | |
324 | delta_us); | |
325 | double percent_pkts, percent_bytes; | |
326 | char fname[100]; | |
327 | FILE *fout; | |
d58c6f72 | 328 | int k; |
329 | static const char *returnValNames[] = { | |
330 | "DROP_PKT", | |
331 | "ALLOW_PKT", | |
332 | "DROP_PKT_CWR", | |
333 | "ALLOW_PKT_CWR" | |
334 | }; | |
335 | #define RET_VAL_COUNT 4 | |
a1270fe9 | 336 | |
337 | // Future support of ingress | |
338 | // if (!outFlag) | |
339 | // sprintf(fname, "hbm.%d.in", cg_id); | |
340 | // else | |
341 | sprintf(fname, "hbm.%d.out", cg_id); | |
342 | fout = fopen(fname, "w"); | |
343 | fprintf(fout, "id:%d\n", cg_id); | |
344 | fprintf(fout, "rate_mbps:%d\n", rate_mbps); | |
345 | fprintf(fout, "duration:%.1f secs\n", | |
346 | (qstats.lastPacketTime - qstats.firstPacketTime) / | |
347 | 1000000000.0); | |
348 | fprintf(fout, "packets:%d\n", (int)qstats.pkts_total); | |
349 | fprintf(fout, "bytes_MB:%d\n", (int)(qstats.bytes_total / | |
350 | 1000000)); | |
351 | fprintf(fout, "pkts_dropped:%d\n", (int)qstats.pkts_dropped); | |
352 | fprintf(fout, "bytes_dropped_MB:%d\n", | |
353 | (int)(qstats.bytes_dropped / | |
354 | 1000000)); | |
355 | // Marked Pkts and Bytes | |
356 | percent_pkts = (qstats.pkts_marked * 100.0) / | |
357 | (qstats.pkts_total + 1); | |
358 | percent_bytes = (qstats.bytes_marked * 100.0) / | |
359 | (qstats.bytes_total + 1); | |
360 | fprintf(fout, "pkts_marked_percent:%6.2f\n", percent_pkts); | |
361 | fprintf(fout, "bytes_marked_percent:%6.2f\n", percent_bytes); | |
362 | ||
363 | // Dropped Pkts and Bytes | |
364 | percent_pkts = (qstats.pkts_dropped * 100.0) / | |
365 | (qstats.pkts_total + 1); | |
366 | percent_bytes = (qstats.bytes_dropped * 100.0) / | |
367 | (qstats.bytes_total + 1); | |
368 | fprintf(fout, "pkts_dropped_percent:%6.2f\n", percent_pkts); | |
369 | fprintf(fout, "bytes_dropped_percent:%6.2f\n", percent_bytes); | |
d58c6f72 | 370 | |
371 | // ECN CE markings | |
372 | percent_pkts = (qstats.pkts_ecn_ce * 100.0) / | |
373 | (qstats.pkts_total + 1); | |
374 | fprintf(fout, "pkts_ecn_ce:%6.2f (%d)\n", percent_pkts, | |
375 | (int)qstats.pkts_ecn_ce); | |
376 | ||
377 | // Average cwnd | |
378 | fprintf(fout, "avg cwnd:%d\n", | |
379 | (int)(qstats.sum_cwnd / (qstats.sum_cwnd_cnt + 1))); | |
380 | // Average rtt | |
381 | fprintf(fout, "avg rtt:%d\n", | |
382 | (int)(qstats.sum_rtt / (qstats.pkts_total + 1))); | |
383 | // Average credit | |
71634d7f | 384 | if (edt_flag) |
385 | fprintf(fout, "avg credit_ms:%.03f\n", | |
386 | (qstats.sum_credit / | |
387 | (qstats.pkts_total + 1.0)) / 1000000.0); | |
388 | else | |
389 | fprintf(fout, "avg credit:%d\n", | |
390 | (int)(qstats.sum_credit / | |
391 | (1500 * ((int)qstats.pkts_total ) + 1))); | |
d58c6f72 | 392 | |
393 | // Return values stats | |
394 | for (k = 0; k < RET_VAL_COUNT; k++) { | |
395 | percent_pkts = (qstats.returnValCount[k] * 100.0) / | |
396 | (qstats.pkts_total + 1); | |
397 | fprintf(fout, "%s:%6.2f (%d)\n", returnValNames[k], | |
398 | percent_pkts, (int)qstats.returnValCount[k]); | |
399 | } | |
a1270fe9 | 400 | fclose(fout); |
401 | } | |
402 | ||
403 | if (debugFlag) | |
404 | read_trace_pipe2(); | |
c5815ac7 DL |
405 | goto cleanup; |
406 | ||
a1270fe9 | 407 | err: |
408 | rc = 1; | |
409 | ||
c5815ac7 DL |
410 | cleanup: |
411 | bpf_link__destroy(link); | |
412 | bpf_object__close(obj); | |
413 | ||
414 | if (cg1 != -1) | |
a1270fe9 | 415 | close(cg1); |
a1270fe9 | 416 | |
c5815ac7 DL |
417 | if (rc != 0) |
418 | cleanup_cgroup_environment(); | |
a1270fe9 | 419 | return rc; |
420 | } | |
421 | ||
422 | static void Usage(void) | |
423 | { | |
424 | printf("This program loads a cgroup skb BPF program to enforce\n" | |
425 | "cgroup output (egress) bandwidth limits.\n\n" | |
ffd81558 | 426 | "USAGE: hbm [-o] [-d] [-l] [-n <id>] [--no_cn] [-r <rate>]\n" |
427 | " [-s] [-t <secs>] [-w] [-h] [prog]\n" | |
a1270fe9 | 428 | " Where:\n" |
429 | " -o indicates egress direction (default)\n" | |
430 | " -d print BPF trace debug buffer\n" | |
71634d7f | 431 | " --edt use fq's Earliest Departure Time\n" |
a1270fe9 | 432 | " -l also limit flows using loopback\n" |
433 | " -n <#> to create cgroup \"/hbm#\" and attach prog\n" | |
434 | " Default is /hbm1\n" | |
2ed99339 | 435 | " --no_cn disable CN notifications\n" |
a1270fe9 | 436 | " -r <rate> Rate in Mbps\n" |
437 | " -s Update HBM stats\n" | |
5b4f21b2 | 438 | " -t <time> Exit after specified seconds (default is 0)\n" |
a1270fe9 | 439 | " -w Work conserving flag. cgroup can increase\n" |
440 | " bandwidth beyond the rate limit specified\n" | |
441 | " while there is available bandwidth. Current\n" | |
442 | " implementation assumes there is only eth0\n" | |
443 | " but can be extended to support multiple NICs\n" | |
444 | " -h print this info\n" | |
445 | " prog BPF program file name. Name defaults to\n" | |
446 | " hbm_out_kern.o\n"); | |
447 | } | |
448 | ||
449 | int main(int argc, char **argv) | |
450 | { | |
451 | char *prog = "hbm_out_kern.o"; | |
452 | int k; | |
453 | int cg_id = 1; | |
454 | char *optstring = "iodln:r:st:wh"; | |
ffd81558 | 455 | struct option loptions[] = { |
456 | {"no_cn", 0, NULL, 1}, | |
71634d7f | 457 | {"edt", 0, NULL, 2}, |
ffd81558 | 458 | {NULL, 0, NULL, 0} |
459 | }; | |
a1270fe9 | 460 | |
ffd81558 | 461 | while ((k = getopt_long(argc, argv, optstring, loptions, NULL)) != -1) { |
a1270fe9 | 462 | switch (k) { |
ffd81558 | 463 | case 1: |
464 | no_cn_flag = true; | |
465 | break; | |
71634d7f | 466 | case 2: |
467 | prog = "hbm_edt_kern.o"; | |
468 | edt_flag = true; | |
469 | break; | |
a1270fe9 | 470 | case'o': |
471 | break; | |
472 | case 'd': | |
473 | debugFlag = true; | |
474 | break; | |
475 | case 'l': | |
476 | loopback_flag = true; | |
477 | break; | |
478 | case 'n': | |
479 | cg_id = atoi(optarg); | |
480 | break; | |
481 | case 'r': | |
482 | minRate = atoi(optarg) * 1.024; | |
483 | rate = minRate; | |
484 | break; | |
485 | case 's': | |
486 | stats_flag = true; | |
487 | break; | |
488 | case 't': | |
489 | dur = atoi(optarg); | |
490 | break; | |
491 | case 'w': | |
492 | work_conserving_flag = true; | |
493 | break; | |
494 | case '?': | |
495 | if (optopt == 'n' || optopt == 'r' || optopt == 't') | |
496 | fprintf(stderr, | |
497 | "Option -%c requires an argument.\n\n", | |
498 | optopt); | |
499 | case 'h': | |
544d6adf | 500 | __fallthrough; |
a1270fe9 | 501 | default: |
502 | Usage(); | |
503 | return 0; | |
504 | } | |
505 | } | |
506 | ||
507 | if (optind < argc) | |
508 | prog = argv[optind]; | |
509 | printf("HBM prog: %s\n", prog != NULL ? prog : "NULL"); | |
510 | ||
b25acdaf YS |
511 | /* Use libbpf 1.0 API mode */ |
512 | libbpf_set_strict_mode(LIBBPF_STRICT_ALL); | |
513 | ||
a1270fe9 | 514 | return run_bpf_prog(prog, cg_id); |
515 | } |