summaryrefslogtreecommitdiffstats
path: root/samples/bpf/hbm.c
diff options
context:
space:
mode:
Diffstat (limited to 'samples/bpf/hbm.c')
-rw-r--r--samples/bpf/hbm.c516
1 files changed, 516 insertions, 0 deletions
diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c
new file mode 100644
index 000000000..7f89700a1
--- /dev/null
+++ b/samples/bpf/hbm.c
@@ -0,0 +1,516 @@
+// 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
+ * --no_cn Do not return cn notifications
+ * -r <rate> Rate limit in Mbps
+ * -s Get HBM stats (marked, dropped, etc.)
+ * -t <time> Exit after specified seconds (default 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/time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/unistd.h>
+#include <linux/compiler.h>
+
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <getopt.h>
+
+#include "cgroup_helpers.h"
+#include "hbm.h"
+#include "bpf_util.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;
+bool no_cn_flag;
+bool edt_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/"
+
+static struct bpf_program *bpf_prog;
+static struct bpf_object *obj;
+static int queue_stats_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_program *pos;
+ const char *sec_name;
+
+ obj = bpf_object__open_file(prog, NULL);
+ if (libbpf_get_error(obj)) {
+ printf("ERROR: opening BPF object file failed\n");
+ return 1;
+ }
+
+ /* load BPF program */
+ if (bpf_object__load(obj)) {
+ printf("ERROR: loading BPF object file failed\n");
+ goto err;
+ }
+
+ bpf_object__for_each_program(pos, obj) {
+ sec_name = bpf_program__section_name(pos);
+ if (sec_name && !strcmp(sec_name, "cgroup_skb/egress")) {
+ bpf_prog = pos;
+ break;
+ }
+ }
+ if (!bpf_prog) {
+ printf("ERROR: finding a prog in obj file failed\n");
+ goto err;
+ }
+
+ queue_stats_fd = bpf_object__find_map_fd_by_name(obj, "queue_stats");
+ if (queue_stats_fd < 0) {
+ printf("ERROR: finding a map in obj file failed\n");
+ goto err;
+ }
+
+ return 0;
+
+err:
+ bpf_object__close(obj);
+ return 1;
+}
+
+static int run_bpf_prog(char *prog, int cg_id)
+{
+ struct hbm_queue_stats qstats = {0};
+ char cg_dir[100], cg_pin_path[100];
+ struct bpf_link *link = NULL;
+ int key = 0;
+ int cg1 = 0;
+ int rc = 0;
+
+ sprintf(cg_dir, "/hbm%d", cg_id);
+ rc = prog_load(prog);
+ if (rc != 0)
+ return rc;
+
+ 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;
+ qstats.no_cn = no_cn_flag ? 1 : 0;
+ if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY)) {
+ printf("ERROR: Could not update map element\n");
+ goto err;
+ }
+
+ if (!outFlag)
+ bpf_program__set_expected_attach_type(bpf_prog, BPF_CGROUP_INET_INGRESS);
+
+ link = bpf_program__attach_cgroup(bpf_prog, cg1);
+ if (libbpf_get_error(link)) {
+ fprintf(stderr, "ERROR: bpf_program__attach_cgroup failed\n");
+ goto err;
+ }
+
+ sprintf(cg_pin_path, "/sys/fs/bpf/hbm%d", cg_id);
+ rc = bpf_link__pin(link, cg_pin_path);
+ if (rc < 0) {
+ printf("ERROR: bpf_link__pin failed: %d\n", rc);
+ 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(queue_stats_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(queue_stats_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(queue_stats_fd, &key, &qstats, BPF_ANY))
+ do_error("update map element fails", false);
+ }
+ } else {
+ sleep(dur);
+ }
+ // Get stats!
+ if (stats_flag && bpf_map_lookup_elem(queue_stats_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");
+ fclose(fout);
+ } 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;
+ int k;
+ static const char *returnValNames[] = {
+ "DROP_PKT",
+ "ALLOW_PKT",
+ "DROP_PKT_CWR",
+ "ALLOW_PKT_CWR"
+ };
+#define RET_VAL_COUNT 4
+
+// 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);
+
+ // ECN CE markings
+ percent_pkts = (qstats.pkts_ecn_ce * 100.0) /
+ (qstats.pkts_total + 1);
+ fprintf(fout, "pkts_ecn_ce:%6.2f (%d)\n", percent_pkts,
+ (int)qstats.pkts_ecn_ce);
+
+ // Average cwnd
+ fprintf(fout, "avg cwnd:%d\n",
+ (int)(qstats.sum_cwnd / (qstats.sum_cwnd_cnt + 1)));
+ // Average rtt
+ fprintf(fout, "avg rtt:%d\n",
+ (int)(qstats.sum_rtt / (qstats.pkts_total + 1)));
+ // Average credit
+ if (edt_flag)
+ fprintf(fout, "avg credit_ms:%.03f\n",
+ (qstats.sum_credit /
+ (qstats.pkts_total + 1.0)) / 1000000.0);
+ else
+ fprintf(fout, "avg credit:%d\n",
+ (int)(qstats.sum_credit /
+ (1500 * ((int)qstats.pkts_total ) + 1)));
+
+ // Return values stats
+ for (k = 0; k < RET_VAL_COUNT; k++) {
+ percent_pkts = (qstats.returnValCount[k] * 100.0) /
+ (qstats.pkts_total + 1);
+ fprintf(fout, "%s:%6.2f (%d)\n", returnValNames[k],
+ percent_pkts, (int)qstats.returnValCount[k]);
+ }
+ fclose(fout);
+ }
+
+ if (debugFlag)
+ read_trace_pipe2();
+ goto cleanup;
+
+err:
+ rc = 1;
+
+cleanup:
+ bpf_link__destroy(link);
+ bpf_object__close(obj);
+
+ if (cg1 != -1)
+ close(cg1);
+
+ if (rc != 0)
+ 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>] [--no_cn] [-r <rate>]\n"
+ " [-s] [-t <secs>] [-w] [-h] [prog]\n"
+ " Where:\n"
+ " -o indicates egress direction (default)\n"
+ " -d print BPF trace debug buffer\n"
+ " --edt use fq's Earliest Departure Time\n"
+ " -l also limit flows using loopback\n"
+ " -n <#> to create cgroup \"/hbm#\" and attach prog\n"
+ " Default is /hbm1\n"
+ " --no_cn disable CN notifications\n"
+ " -r <rate> Rate in Mbps\n"
+ " -s Update HBM stats\n"
+ " -t <time> Exit after specified seconds (default 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";
+ struct option loptions[] = {
+ {"no_cn", 0, NULL, 1},
+ {"edt", 0, NULL, 2},
+ {NULL, 0, NULL, 0}
+ };
+
+ while ((k = getopt_long(argc, argv, optstring, loptions, NULL)) != -1) {
+ switch (k) {
+ case 1:
+ no_cn_flag = true;
+ break;
+ case 2:
+ prog = "hbm_edt_kern.o";
+ edt_flag = true;
+ break;
+ 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");
+
+ /* Use libbpf 1.0 API mode */
+ libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+
+ return run_bpf_prog(prog, cg_id);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-17 14:37:35 +0000