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Diffstat (limited to 'samples/bpf/hbm.c')
| -rw-r--r-- | samples/bpf/hbm.c | 441 |
1 files changed, 441 insertions, 0 deletions
diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c new file mode 100644 index 000000000000..8408ccb7409f --- /dev/null +++ b/samples/bpf/hbm.c @@ -0,0 +1,441 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Facebook + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * Example program for Host Bandwidth Managment + * + * This program loads a cgroup skb BPF program to enforce cgroup output + * (egress) or input (ingress) bandwidth limits. + * + * USAGE: hbm [-d] [-l] [-n <id>] [-r <rate>] [-s] [-t <secs>] [-w] [-h] [prog] + * Where: + * -d Print BPF trace debug buffer + * -l Also limit flows doing loopback + * -n <#> To create cgroup \"/hbm#\" and attach prog + * Default is /hbm1 + * -r <rate> Rate limit in Mbps + * -s Get HBM stats (marked, dropped, etc.) + * -t <time> Exit after specified seconds (deault is 0) + * -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 + * NIC (eth0), but can be extended to support multiple NICs. + * Currrently only supported for egress. + * -h Print this info + * prog BPF program file name. Name defaults to hbm_out_kern.o + */ + +#define _GNU_SOURCE + +#include <stdio.h> +#include <stdlib.h> +#include <assert.h> +#include <sys/resource.h> +#include <sys/time.h> +#include <unistd.h> +#include <errno.h> +#include <fcntl.h> +#include <linux/unistd.h> + +#include <linux/bpf.h> +#include <bpf/bpf.h> + +#include "bpf_load.h" +#include "bpf_rlimit.h" +#include "cgroup_helpers.h" +#include "hbm.h" +#include "bpf_util.h" +#include "bpf/bpf.h" +#include "bpf/libbpf.h" + +bool outFlag = true; +int minRate = 1000; /* cgroup rate limit in Mbps */ +int rate = 1000; /* can grow if rate conserving is enabled */ +int dur = 1; +bool stats_flag; +bool loopback_flag; +bool debugFlag; +bool work_conserving_flag; + +static void Usage(void); +static void read_trace_pipe2(void); +static void do_error(char *msg, bool errno_flag); + +#define DEBUGFS "/sys/kernel/debug/tracing/" + +struct bpf_object *obj; +int bpfprog_fd; +int cgroup_storage_fd; + +static void read_trace_pipe2(void) +{ + int trace_fd; + FILE *outf; + char *outFname = "hbm_out.log"; + + trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0); + if (trace_fd < 0) { + printf("Error opening trace_pipe\n"); + return; + } + +// Future support of ingress +// if (!outFlag) +// outFname = "hbm_in.log"; + outf = fopen(outFname, "w"); + + if (outf == NULL) + printf("Error creating %s\n", outFname); + + while (1) { + static char buf[4097]; + ssize_t sz; + + sz = read(trace_fd, buf, sizeof(buf) - 1); + if (sz > 0) { + buf[sz] = 0; + puts(buf); + if (outf != NULL) { + fprintf(outf, "%s\n", buf); + fflush(outf); + } + } + } +} + +static void do_error(char *msg, bool errno_flag) +{ + if (errno_flag) + printf("ERROR: %s, errno: %d\n", msg, errno); + else + printf("ERROR: %s\n", msg); + exit(1); +} + +static int prog_load(char *prog) +{ + struct bpf_prog_load_attr prog_load_attr = { + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + .file = prog, + .expected_attach_type = BPF_CGROUP_INET_EGRESS, + }; + int map_fd; + struct bpf_map *map; + + int ret = 0; + + if (access(prog, O_RDONLY) < 0) { + printf("Error accessing file %s: %s\n", prog, strerror(errno)); + return 1; + } + if (bpf_prog_load_xattr(&prog_load_attr, &obj, &bpfprog_fd)) + ret = 1; + if (!ret) { + map = bpf_object__find_map_by_name(obj, "queue_stats"); + map_fd = bpf_map__fd(map); + if (map_fd < 0) { + printf("Map not found: %s\n", strerror(map_fd)); + ret = 1; + } + } + + if (ret) { + printf("ERROR: load_bpf_file failed for: %s\n", prog); + printf(" Output from verifier:\n%s\n------\n", bpf_log_buf); + ret = -1; + } else { + ret = map_fd; + } + + return ret; +} + +static int run_bpf_prog(char *prog, int cg_id) +{ + int map_fd; + int rc = 0; + int key = 0; + int cg1 = 0; + int type = BPF_CGROUP_INET_EGRESS; + char cg_dir[100]; + struct hbm_queue_stats qstats = {0}; + + sprintf(cg_dir, "/hbm%d", cg_id); + map_fd = prog_load(prog); + if (map_fd == -1) + return 1; + + if (setup_cgroup_environment()) { + printf("ERROR: setting cgroup environment\n"); + goto err; + } + cg1 = create_and_get_cgroup(cg_dir); + if (!cg1) { + printf("ERROR: create_and_get_cgroup\n"); + goto err; + } + if (join_cgroup(cg_dir)) { + printf("ERROR: join_cgroup\n"); + goto err; + } + + qstats.rate = rate; + qstats.stats = stats_flag ? 1 : 0; + qstats.loopback = loopback_flag ? 1 : 0; + if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY)) { + printf("ERROR: Could not update map element\n"); + goto err; + } + + if (!outFlag) + type = BPF_CGROUP_INET_INGRESS; + if (bpf_prog_attach(bpfprog_fd, cg1, type, 0)) { + printf("ERROR: bpf_prog_attach fails!\n"); + log_err("Attaching prog"); + goto err; + } + + if (work_conserving_flag) { + struct timeval t0, t_last, t_new; + FILE *fin; + unsigned long long last_eth_tx_bytes, new_eth_tx_bytes; + signed long long last_cg_tx_bytes, new_cg_tx_bytes; + signed long long delta_time, delta_bytes, delta_rate; + int delta_ms; +#define DELTA_RATE_CHECK 10000 /* in us */ +#define RATE_THRESHOLD 9500000000 /* 9.5 Gbps */ + + bpf_map_lookup_elem(map_fd, &key, &qstats); + if (gettimeofday(&t0, NULL) < 0) + do_error("gettimeofday failed", true); + t_last = t0; + fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", "r"); + if (fscanf(fin, "%llu", &last_eth_tx_bytes) != 1) + do_error("fscanf fails", false); + fclose(fin); + last_cg_tx_bytes = qstats.bytes_total; + while (true) { + usleep(DELTA_RATE_CHECK); + if (gettimeofday(&t_new, NULL) < 0) + do_error("gettimeofday failed", true); + delta_ms = (t_new.tv_sec - t0.tv_sec) * 1000 + + (t_new.tv_usec - t0.tv_usec)/1000; + if (delta_ms > dur * 1000) + break; + delta_time = (t_new.tv_sec - t_last.tv_sec) * 1000000 + + (t_new.tv_usec - t_last.tv_usec); + if (delta_time == 0) + continue; + t_last = t_new; + fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", + "r"); + if (fscanf(fin, "%llu", &new_eth_tx_bytes) != 1) + do_error("fscanf fails", false); + fclose(fin); + printf(" new_eth_tx_bytes:%llu\n", + new_eth_tx_bytes); + bpf_map_lookup_elem(map_fd, &key, &qstats); + new_cg_tx_bytes = qstats.bytes_total; + delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes; + last_eth_tx_bytes = new_eth_tx_bytes; + delta_rate = (delta_bytes * 8000000) / delta_time; + printf("%5d - eth_rate:%.1fGbps cg_rate:%.3fGbps", + delta_ms, delta_rate/1000000000.0, + rate/1000.0); + if (delta_rate < RATE_THRESHOLD) { + /* can increase cgroup rate limit, but first + * check if we are using the current limit. + * Currently increasing by 6.25%, unknown + * if that is the optimal rate. + */ + int rate_diff100; + + delta_bytes = new_cg_tx_bytes - + last_cg_tx_bytes; + last_cg_tx_bytes = new_cg_tx_bytes; + delta_rate = (delta_bytes * 8000000) / + delta_time; + printf(" rate:%.3fGbps", + delta_rate/1000000000.0); + rate_diff100 = (((long long)rate)*1000000 - + delta_rate) * 100 / + (((long long) rate) * 1000000); + printf(" rdiff:%d", rate_diff100); + if (rate_diff100 <= 3) { + rate += (rate >> 4); + if (rate > RATE_THRESHOLD / 1000000) + rate = RATE_THRESHOLD / 1000000; + qstats.rate = rate; + printf(" INC\n"); + } else { + printf("\n"); + } + } else { + /* Need to decrease cgroup rate limit. + * Currently decreasing by 12.5%, unknown + * if that is optimal + */ + printf(" DEC\n"); + rate -= (rate >> 3); + if (rate < minRate) + rate = minRate; + qstats.rate = rate; + } + if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY)) + do_error("update map element fails", false); + } + } else { + sleep(dur); + } + // Get stats! + if (stats_flag && bpf_map_lookup_elem(map_fd, &key, &qstats)) { + char fname[100]; + FILE *fout; + + if (!outFlag) + sprintf(fname, "hbm.%d.in", cg_id); + else + sprintf(fname, "hbm.%d.out", cg_id); + fout = fopen(fname, "w"); + fprintf(fout, "id:%d\n", cg_id); + fprintf(fout, "ERROR: Could not lookup queue_stats\n"); + } else if (stats_flag && qstats.lastPacketTime > + qstats.firstPacketTime) { + long long delta_us = (qstats.lastPacketTime - + qstats.firstPacketTime)/1000; + unsigned int rate_mbps = ((qstats.bytes_total - + qstats.bytes_dropped) * 8 / + delta_us); + double percent_pkts, percent_bytes; + char fname[100]; + FILE *fout; + +// Future support of ingress +// if (!outFlag) +// sprintf(fname, "hbm.%d.in", cg_id); +// else + sprintf(fname, "hbm.%d.out", cg_id); + fout = fopen(fname, "w"); + fprintf(fout, "id:%d\n", cg_id); + fprintf(fout, "rate_mbps:%d\n", rate_mbps); + fprintf(fout, "duration:%.1f secs\n", + (qstats.lastPacketTime - qstats.firstPacketTime) / + 1000000000.0); + fprintf(fout, "packets:%d\n", (int)qstats.pkts_total); + fprintf(fout, "bytes_MB:%d\n", (int)(qstats.bytes_total / + 1000000)); + fprintf(fout, "pkts_dropped:%d\n", (int)qstats.pkts_dropped); + fprintf(fout, "bytes_dropped_MB:%d\n", + (int)(qstats.bytes_dropped / + 1000000)); + // Marked Pkts and Bytes + percent_pkts = (qstats.pkts_marked * 100.0) / + (qstats.pkts_total + 1); + percent_bytes = (qstats.bytes_marked * 100.0) / + (qstats.bytes_total + 1); + fprintf(fout, "pkts_marked_percent:%6.2f\n", percent_pkts); + fprintf(fout, "bytes_marked_percent:%6.2f\n", percent_bytes); + + // Dropped Pkts and Bytes + percent_pkts = (qstats.pkts_dropped * 100.0) / + (qstats.pkts_total + 1); + percent_bytes = (qstats.bytes_dropped * 100.0) / + (qstats.bytes_total + 1); + fprintf(fout, "pkts_dropped_percent:%6.2f\n", percent_pkts); + fprintf(fout, "bytes_dropped_percent:%6.2f\n", percent_bytes); + fclose(fout); + } + + if (debugFlag) + read_trace_pipe2(); + return rc; +err: + rc = 1; + + if (cg1) + close(cg1); + cleanup_cgroup_environment(); + + return rc; +} + +static void Usage(void) +{ + printf("This program loads a cgroup skb BPF program to enforce\n" + "cgroup output (egress) bandwidth limits.\n\n" + "USAGE: hbm [-o] [-d] [-l] [-n <id>] [-r <rate>] [-s]\n" + " [-t <secs>] [-w] [-h] [prog]\n" + " Where:\n" + " -o indicates egress direction (default)\n" + " -d print BPF trace debug buffer\n" + " -l also limit flows using loopback\n" + " -n <#> to create cgroup \"/hbm#\" and attach prog\n" + " Default is /hbm1\n" + " -r <rate> Rate in Mbps\n" + " -s Update HBM stats\n" + " -t <time> Exit after specified seconds (deault is 0)\n" + " -w Work conserving flag. cgroup can increase\n" + " bandwidth beyond the rate limit specified\n" + " while there is available bandwidth. Current\n" + " implementation assumes there is only eth0\n" + " but can be extended to support multiple NICs\n" + " -h print this info\n" + " prog BPF program file name. Name defaults to\n" + " hbm_out_kern.o\n"); +} + +int main(int argc, char **argv) +{ + char *prog = "hbm_out_kern.o"; + int k; + int cg_id = 1; + char *optstring = "iodln:r:st:wh"; + + while ((k = getopt(argc, argv, optstring)) != -1) { + switch (k) { + case'o': + break; + case 'd': + debugFlag = true; + break; + case 'l': + loopback_flag = true; + break; + case 'n': + cg_id = atoi(optarg); + break; + case 'r': + minRate = atoi(optarg) * 1.024; + rate = minRate; + break; + case 's': + stats_flag = true; + break; + case 't': + dur = atoi(optarg); + break; + case 'w': + work_conserving_flag = true; + break; + case '?': + if (optopt == 'n' || optopt == 'r' || optopt == 't') + fprintf(stderr, + "Option -%c requires an argument.\n\n", + optopt); + case 'h': + // fallthrough + default: + Usage(); + return 0; + } + } + + if (optind < argc) + prog = argv[optind]; + printf("HBM prog: %s\n", prog != NULL ? prog : "NULL"); + + return run_bpf_prog(prog, cg_id); +} |