544d6adf3c
Compiling samples/bpf hits an error related to fallthrough marking. ... CC samples/bpf/hbm.o samples/bpf/hbm.c: In function ‘main’: samples/bpf/hbm.c:486:4: error: ‘fallthrough’ undeclared (first use in this function) fallthrough; ^~~~~~~~~~~ The "fallthrough" is not defined under tools/include directory. Rather, it is "__fallthrough" is defined in linux/compiler.h. Including "linux/compiler.h" and using "__fallthrough" fixed the issue. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201006043427.1891805-1-yhs@fb.com
500 lines
13 KiB
C
500 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2019 Facebook
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* Example program for Host Bandwidth Managment
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*
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* This program loads a cgroup skb BPF program to enforce cgroup output
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* (egress) or input (ingress) bandwidth limits.
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*
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* USAGE: hbm [-d] [-l] [-n <id>] [-r <rate>] [-s] [-t <secs>] [-w] [-h] [prog]
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* Where:
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* -d Print BPF trace debug buffer
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* -l Also limit flows doing loopback
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* -n <#> To create cgroup \"/hbm#\" and attach prog
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* Default is /hbm1
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* --no_cn Do not return cn notifications
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* -r <rate> Rate limit in Mbps
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* -s Get HBM stats (marked, dropped, etc.)
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* -t <time> Exit after specified seconds (default is 0)
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* -w Work conserving flag. cgroup can increase its bandwidth
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* beyond the rate limit specified while there is available
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* bandwidth. Current implementation assumes there is only
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* NIC (eth0), but can be extended to support multiple NICs.
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* Currrently only supported for egress.
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* -h Print this info
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* prog BPF program file name. Name defaults to hbm_out_kern.o
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*/
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#define _GNU_SOURCE
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <sys/resource.h>
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#include <sys/time.h>
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#include <unistd.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <linux/unistd.h>
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#include <linux/compiler.h>
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#include <linux/bpf.h>
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#include <bpf/bpf.h>
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#include <getopt.h>
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#include "bpf_load.h"
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#include "bpf_rlimit.h"
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#include "cgroup_helpers.h"
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#include "hbm.h"
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#include "bpf_util.h"
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#include <bpf/bpf.h>
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#include <bpf/libbpf.h>
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bool outFlag = true;
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int minRate = 1000; /* cgroup rate limit in Mbps */
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int rate = 1000; /* can grow if rate conserving is enabled */
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int dur = 1;
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bool stats_flag;
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bool loopback_flag;
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bool debugFlag;
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bool work_conserving_flag;
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bool no_cn_flag;
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bool edt_flag;
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static void Usage(void);
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static void read_trace_pipe2(void);
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static void do_error(char *msg, bool errno_flag);
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#define DEBUGFS "/sys/kernel/debug/tracing/"
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struct bpf_object *obj;
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int bpfprog_fd;
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int cgroup_storage_fd;
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static void read_trace_pipe2(void)
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{
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int trace_fd;
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FILE *outf;
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char *outFname = "hbm_out.log";
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trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
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if (trace_fd < 0) {
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printf("Error opening trace_pipe\n");
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return;
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}
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// Future support of ingress
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// if (!outFlag)
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// outFname = "hbm_in.log";
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outf = fopen(outFname, "w");
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if (outf == NULL)
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printf("Error creating %s\n", outFname);
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while (1) {
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static char buf[4097];
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ssize_t sz;
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sz = read(trace_fd, buf, sizeof(buf) - 1);
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if (sz > 0) {
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buf[sz] = 0;
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puts(buf);
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if (outf != NULL) {
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fprintf(outf, "%s\n", buf);
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fflush(outf);
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}
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}
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}
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}
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static void do_error(char *msg, bool errno_flag)
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{
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if (errno_flag)
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printf("ERROR: %s, errno: %d\n", msg, errno);
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else
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printf("ERROR: %s\n", msg);
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exit(1);
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}
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static int prog_load(char *prog)
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{
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struct bpf_prog_load_attr prog_load_attr = {
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.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
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.file = prog,
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.expected_attach_type = BPF_CGROUP_INET_EGRESS,
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};
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int map_fd;
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struct bpf_map *map;
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int ret = 0;
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if (access(prog, O_RDONLY) < 0) {
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printf("Error accessing file %s: %s\n", prog, strerror(errno));
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return 1;
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}
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if (bpf_prog_load_xattr(&prog_load_attr, &obj, &bpfprog_fd))
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ret = 1;
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if (!ret) {
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map = bpf_object__find_map_by_name(obj, "queue_stats");
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map_fd = bpf_map__fd(map);
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if (map_fd < 0) {
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printf("Map not found: %s\n", strerror(map_fd));
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ret = 1;
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}
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}
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if (ret) {
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printf("ERROR: bpf_prog_load_xattr failed for: %s\n", prog);
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printf(" Output from verifier:\n%s\n------\n", bpf_log_buf);
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ret = -1;
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} else {
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ret = map_fd;
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}
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return ret;
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}
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static int run_bpf_prog(char *prog, int cg_id)
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{
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int map_fd;
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int rc = 0;
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int key = 0;
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int cg1 = 0;
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int type = BPF_CGROUP_INET_EGRESS;
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char cg_dir[100];
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struct hbm_queue_stats qstats = {0};
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sprintf(cg_dir, "/hbm%d", cg_id);
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map_fd = prog_load(prog);
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if (map_fd == -1)
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return 1;
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if (setup_cgroup_environment()) {
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printf("ERROR: setting cgroup environment\n");
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goto err;
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}
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cg1 = create_and_get_cgroup(cg_dir);
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if (!cg1) {
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printf("ERROR: create_and_get_cgroup\n");
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goto err;
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}
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if (join_cgroup(cg_dir)) {
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printf("ERROR: join_cgroup\n");
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goto err;
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}
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qstats.rate = rate;
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qstats.stats = stats_flag ? 1 : 0;
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qstats.loopback = loopback_flag ? 1 : 0;
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qstats.no_cn = no_cn_flag ? 1 : 0;
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if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY)) {
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printf("ERROR: Could not update map element\n");
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goto err;
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}
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if (!outFlag)
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type = BPF_CGROUP_INET_INGRESS;
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if (bpf_prog_attach(bpfprog_fd, cg1, type, 0)) {
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printf("ERROR: bpf_prog_attach fails!\n");
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log_err("Attaching prog");
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goto err;
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}
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if (work_conserving_flag) {
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struct timeval t0, t_last, t_new;
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FILE *fin;
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unsigned long long last_eth_tx_bytes, new_eth_tx_bytes;
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signed long long last_cg_tx_bytes, new_cg_tx_bytes;
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signed long long delta_time, delta_bytes, delta_rate;
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int delta_ms;
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#define DELTA_RATE_CHECK 10000 /* in us */
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#define RATE_THRESHOLD 9500000000 /* 9.5 Gbps */
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bpf_map_lookup_elem(map_fd, &key, &qstats);
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if (gettimeofday(&t0, NULL) < 0)
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do_error("gettimeofday failed", true);
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t_last = t0;
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fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", "r");
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if (fscanf(fin, "%llu", &last_eth_tx_bytes) != 1)
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do_error("fscanf fails", false);
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fclose(fin);
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last_cg_tx_bytes = qstats.bytes_total;
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while (true) {
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usleep(DELTA_RATE_CHECK);
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if (gettimeofday(&t_new, NULL) < 0)
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do_error("gettimeofday failed", true);
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delta_ms = (t_new.tv_sec - t0.tv_sec) * 1000 +
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(t_new.tv_usec - t0.tv_usec)/1000;
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if (delta_ms > dur * 1000)
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break;
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delta_time = (t_new.tv_sec - t_last.tv_sec) * 1000000 +
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(t_new.tv_usec - t_last.tv_usec);
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if (delta_time == 0)
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continue;
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t_last = t_new;
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fin = fopen("/sys/class/net/eth0/statistics/tx_bytes",
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"r");
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if (fscanf(fin, "%llu", &new_eth_tx_bytes) != 1)
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do_error("fscanf fails", false);
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fclose(fin);
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printf(" new_eth_tx_bytes:%llu\n",
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new_eth_tx_bytes);
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bpf_map_lookup_elem(map_fd, &key, &qstats);
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new_cg_tx_bytes = qstats.bytes_total;
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delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes;
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last_eth_tx_bytes = new_eth_tx_bytes;
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delta_rate = (delta_bytes * 8000000) / delta_time;
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printf("%5d - eth_rate:%.1fGbps cg_rate:%.3fGbps",
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delta_ms, delta_rate/1000000000.0,
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rate/1000.0);
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if (delta_rate < RATE_THRESHOLD) {
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/* can increase cgroup rate limit, but first
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* check if we are using the current limit.
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* Currently increasing by 6.25%, unknown
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* if that is the optimal rate.
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*/
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int rate_diff100;
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delta_bytes = new_cg_tx_bytes -
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last_cg_tx_bytes;
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last_cg_tx_bytes = new_cg_tx_bytes;
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delta_rate = (delta_bytes * 8000000) /
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delta_time;
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printf(" rate:%.3fGbps",
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delta_rate/1000000000.0);
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rate_diff100 = (((long long)rate)*1000000 -
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delta_rate) * 100 /
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(((long long) rate) * 1000000);
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printf(" rdiff:%d", rate_diff100);
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if (rate_diff100 <= 3) {
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rate += (rate >> 4);
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if (rate > RATE_THRESHOLD / 1000000)
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rate = RATE_THRESHOLD / 1000000;
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qstats.rate = rate;
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printf(" INC\n");
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} else {
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printf("\n");
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}
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} else {
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/* Need to decrease cgroup rate limit.
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* Currently decreasing by 12.5%, unknown
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* if that is optimal
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*/
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printf(" DEC\n");
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rate -= (rate >> 3);
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if (rate < minRate)
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rate = minRate;
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qstats.rate = rate;
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}
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if (bpf_map_update_elem(map_fd, &key, &qstats, BPF_ANY))
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do_error("update map element fails", false);
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}
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} else {
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sleep(dur);
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}
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// Get stats!
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if (stats_flag && bpf_map_lookup_elem(map_fd, &key, &qstats)) {
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char fname[100];
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FILE *fout;
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if (!outFlag)
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sprintf(fname, "hbm.%d.in", cg_id);
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else
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sprintf(fname, "hbm.%d.out", cg_id);
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fout = fopen(fname, "w");
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fprintf(fout, "id:%d\n", cg_id);
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fprintf(fout, "ERROR: Could not lookup queue_stats\n");
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} else if (stats_flag && qstats.lastPacketTime >
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qstats.firstPacketTime) {
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long long delta_us = (qstats.lastPacketTime -
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qstats.firstPacketTime)/1000;
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unsigned int rate_mbps = ((qstats.bytes_total -
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qstats.bytes_dropped) * 8 /
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delta_us);
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double percent_pkts, percent_bytes;
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char fname[100];
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FILE *fout;
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int k;
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static const char *returnValNames[] = {
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"DROP_PKT",
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"ALLOW_PKT",
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"DROP_PKT_CWR",
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"ALLOW_PKT_CWR"
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};
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#define RET_VAL_COUNT 4
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// Future support of ingress
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// if (!outFlag)
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// sprintf(fname, "hbm.%d.in", cg_id);
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// else
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sprintf(fname, "hbm.%d.out", cg_id);
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fout = fopen(fname, "w");
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fprintf(fout, "id:%d\n", cg_id);
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fprintf(fout, "rate_mbps:%d\n", rate_mbps);
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fprintf(fout, "duration:%.1f secs\n",
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(qstats.lastPacketTime - qstats.firstPacketTime) /
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1000000000.0);
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fprintf(fout, "packets:%d\n", (int)qstats.pkts_total);
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fprintf(fout, "bytes_MB:%d\n", (int)(qstats.bytes_total /
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1000000));
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fprintf(fout, "pkts_dropped:%d\n", (int)qstats.pkts_dropped);
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fprintf(fout, "bytes_dropped_MB:%d\n",
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(int)(qstats.bytes_dropped /
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1000000));
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// Marked Pkts and Bytes
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percent_pkts = (qstats.pkts_marked * 100.0) /
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(qstats.pkts_total + 1);
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percent_bytes = (qstats.bytes_marked * 100.0) /
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(qstats.bytes_total + 1);
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fprintf(fout, "pkts_marked_percent:%6.2f\n", percent_pkts);
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fprintf(fout, "bytes_marked_percent:%6.2f\n", percent_bytes);
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// Dropped Pkts and Bytes
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percent_pkts = (qstats.pkts_dropped * 100.0) /
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(qstats.pkts_total + 1);
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percent_bytes = (qstats.bytes_dropped * 100.0) /
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(qstats.bytes_total + 1);
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fprintf(fout, "pkts_dropped_percent:%6.2f\n", percent_pkts);
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fprintf(fout, "bytes_dropped_percent:%6.2f\n", percent_bytes);
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// ECN CE markings
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percent_pkts = (qstats.pkts_ecn_ce * 100.0) /
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(qstats.pkts_total + 1);
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fprintf(fout, "pkts_ecn_ce:%6.2f (%d)\n", percent_pkts,
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(int)qstats.pkts_ecn_ce);
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// Average cwnd
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fprintf(fout, "avg cwnd:%d\n",
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(int)(qstats.sum_cwnd / (qstats.sum_cwnd_cnt + 1)));
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// Average rtt
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fprintf(fout, "avg rtt:%d\n",
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(int)(qstats.sum_rtt / (qstats.pkts_total + 1)));
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// Average credit
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if (edt_flag)
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fprintf(fout, "avg credit_ms:%.03f\n",
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(qstats.sum_credit /
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(qstats.pkts_total + 1.0)) / 1000000.0);
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else
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fprintf(fout, "avg credit:%d\n",
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(int)(qstats.sum_credit /
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(1500 * ((int)qstats.pkts_total ) + 1)));
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// Return values stats
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for (k = 0; k < RET_VAL_COUNT; k++) {
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percent_pkts = (qstats.returnValCount[k] * 100.0) /
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(qstats.pkts_total + 1);
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fprintf(fout, "%s:%6.2f (%d)\n", returnValNames[k],
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percent_pkts, (int)qstats.returnValCount[k]);
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}
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fclose(fout);
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}
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if (debugFlag)
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read_trace_pipe2();
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return rc;
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err:
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rc = 1;
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if (cg1)
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close(cg1);
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cleanup_cgroup_environment();
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return rc;
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}
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static void Usage(void)
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{
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printf("This program loads a cgroup skb BPF program to enforce\n"
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"cgroup output (egress) bandwidth limits.\n\n"
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"USAGE: hbm [-o] [-d] [-l] [-n <id>] [--no_cn] [-r <rate>]\n"
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" [-s] [-t <secs>] [-w] [-h] [prog]\n"
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" Where:\n"
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" -o indicates egress direction (default)\n"
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" -d print BPF trace debug buffer\n"
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" --edt use fq's Earliest Departure Time\n"
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" -l also limit flows using loopback\n"
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" -n <#> to create cgroup \"/hbm#\" and attach prog\n"
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" Default is /hbm1\n"
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" --no_cn disable CN notifications\n"
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" -r <rate> Rate in Mbps\n"
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" -s Update HBM stats\n"
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" -t <time> Exit after specified seconds (default is 0)\n"
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" -w Work conserving flag. cgroup can increase\n"
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" bandwidth beyond the rate limit specified\n"
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" while there is available bandwidth. Current\n"
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" implementation assumes there is only eth0\n"
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" but can be extended to support multiple NICs\n"
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" -h print this info\n"
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" prog BPF program file name. Name defaults to\n"
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" hbm_out_kern.o\n");
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}
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int main(int argc, char **argv)
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{
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char *prog = "hbm_out_kern.o";
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int k;
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int cg_id = 1;
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char *optstring = "iodln:r:st:wh";
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struct option loptions[] = {
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{"no_cn", 0, NULL, 1},
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{"edt", 0, NULL, 2},
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{NULL, 0, NULL, 0}
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};
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while ((k = getopt_long(argc, argv, optstring, loptions, NULL)) != -1) {
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switch (k) {
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case 1:
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no_cn_flag = true;
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break;
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case 2:
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prog = "hbm_edt_kern.o";
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edt_flag = true;
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break;
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case'o':
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break;
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case 'd':
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debugFlag = true;
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break;
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case 'l':
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loopback_flag = true;
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break;
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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);
|
|
}
|