libbpf-tools/cpudist.c - platform/external/bcc - Git at Google

 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 // Copyright (c) 2020 Wenbo Zhang
 //
 // Based on cpudist(8) from BCC by Brendan Gregg & Dina Goldshtein.
 // 8-May-2020   Wenbo Zhang   Created this.
 #include <argp.h>
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <time.h>
 #include <fcntl.h>
 #include <bpf/libbpf.h>
 #include <bpf/bpf.h>
 #include "cpudist.h"
 #include "cpudist.skel.h"
 #include "trace_helpers.h"

 static struct env {
 	time_t interval;
 	pid_t pid;
 	char *cgroupspath;
 	bool cg;
 	int times;
 	bool offcpu;
 	bool timestamp;
 	bool per_process;
 	bool per_thread;
 	bool milliseconds;
 	bool verbose;
 } env = {
 	.interval = 99999999,
 	.pid = -1,
 	.times = 99999999,
 };

 static volatile bool exiting;

 const char *argp_program_version = "cpudist 0.1";
 const char *argp_program_bug_address =
 	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
 const char argp_program_doc[] =
 "Summarize on-CPU time per task as a histogram.\n"
 "\n"
 "USAGE: cpudist [--help] [-O] [-T] [-m] [-P] [-L] [-p PID] [interval] [count] [-c CG]\n"
 "\n"
 "EXAMPLES:\n"
 "    cpudist              # summarize on-CPU time as a histogram"
 "    cpudist -O           # summarize off-CPU time as a histogram"
 "    cpudist -c CG        # Trace process under cgroupsPath CG\n"
 "    cpudist 1 10         # print 1 second summaries, 10 times"
 "    cpudist -mT 1        # 1s summaries, milliseconds, and timestamps"
 "    cpudist -P           # show each PID separately"
 "    cpudist -p 185       # trace PID 185 only";

 static const struct argp_option opts[] = {
 	{ "offcpu", 'O', NULL, 0, "Measure off-CPU time" },
 	{ "timestamp", 'T', NULL, 0, "Include timestamp on output" },
 	{ "milliseconds", 'm', NULL, 0, "Millisecond histogram" },
 	{ "cgroup", 'c', "/sys/fs/cgroup/unified", 0, "Trace process in cgroup path" },
 	{ "pids", 'P', NULL, 0, "Print a histogram per process ID" },
 	{ "tids", 'L', NULL, 0, "Print a histogram per thread ID" },
 	{ "pid", 'p', "PID", 0, "Trace this PID only" },
 	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
 	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
 	{},
 };

 static error_t parse_arg(int key, char *arg, struct argp_state *state)
 {
 	static int pos_args;

 	switch (key) {
 	case 'h':
 		argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
 		break;
 	case 'v':
 		env.verbose = true;
 		break;
 	case 'm':
 		env.milliseconds = true;
 		break;
 	case 'c':
 		env.cgroupspath = arg;
 		env.cg = true;
 		break;
 	case 'p':
 		errno = 0;
 		env.pid = strtol(arg, NULL, 10);
 		if (errno) {
 			fprintf(stderr, "invalid PID: %s\n", arg);
 			argp_usage(state);
 		}
 		break;
 	case 'O':
 		env.offcpu = true;
 		break;
 	case 'P':
 		env.per_process = true;
 		break;
 	case 'L':
 		env.per_thread = true;
 		break;
 	case 'T':
 		env.timestamp = true;
 		break;
 	case ARGP_KEY_ARG:
 		errno = 0;
 		if (pos_args == 0) {
 			env.interval = strtol(arg, NULL, 10);
 			if (errno) {
 				fprintf(stderr, "invalid internal\n");
 				argp_usage(state);
 			}
 		} else if (pos_args == 1) {
 			env.times = strtol(arg, NULL, 10);
 			if (errno) {
 				fprintf(stderr, "invalid times\n");
 				argp_usage(state);
 			}
 		} else {
 			fprintf(stderr,
 				"unrecognized positional argument: %s\n", arg);
 			argp_usage(state);
 		}
 		pos_args++;
 		break;
 	default:
 		return ARGP_ERR_UNKNOWN;
 	}
 	return 0;
 }

 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
 {
 	if (level == LIBBPF_DEBUG && !env.verbose)
 		return 0;
 	return vfprintf(stderr, format, args);
 }

 static int get_pid_max(void)
 {
 	int pid_max;
 	FILE *f;

 	f = fopen("/proc/sys/kernel/pid_max", "r");
 	if (!f)
 		return -1;
 	if (fscanf(f, "%d\n", &pid_max) != 1)
 		pid_max = -1;
 	fclose(f);
 	return pid_max;
 }

 static void sig_handler(int sig)
 {
 	exiting = true;
 }

 static int print_log2_hists(int fd)
 {
 	char *units = env.milliseconds ? "msecs" : "usecs";
 	__u32 lookup_key = -2, next_key;
 	struct hist hist;
 	int err;

 	while (!bpf_map_get_next_key(fd, &lookup_key, &next_key)) {
 		err = bpf_map_lookup_elem(fd, &next_key, &hist);
 		if (err < 0) {
 			fprintf(stderr, "failed to lookup hist: %d\n", err);
 			return -1;
 		}
 		if (env.per_process)
 			printf("\npid = %d %s\n", next_key, hist.comm);
 		if (env.per_thread)
 			printf("\ntid = %d %s\n", next_key, hist.comm);
 		print_log2_hist(hist.slots, MAX_SLOTS, units);
 		lookup_key = next_key;
 	}

 	lookup_key = -2;
 	while (!bpf_map_get_next_key(fd, &lookup_key, &next_key)) {
 		err = bpf_map_delete_elem(fd, &next_key);
 		if (err < 0) {
 			fprintf(stderr, "failed to cleanup hist : %d\n", err);
 			return -1;
 		}
 		lookup_key = next_key;
 	}
 	return 0;
 }

 int main(int argc, char **argv)
 {
 	static const struct argp argp = {
 		.options = opts,
 		.parser = parse_arg,
 		.doc = argp_program_doc,
 	};
 	struct cpudist_bpf *obj;
 	int pid_max, fd, err;
 	struct tm *tm;
 	char ts[32];
 	time_t t;
 	int idx, cg_map_fd;
 	int cgfd = -1;

 	err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
 	if (err)
 		return err;

 	libbpf_set_print(libbpf_print_fn);

 	obj = cpudist_bpf__open();
 	if (!obj) {
 		fprintf(stderr, "failed to open BPF object\n");
 		return 1;
 	}

 	if (probe_tp_btf("sched_switch"))
 		bpf_program__set_autoload(obj->progs.sched_switch_tp, false);
 	else
 		bpf_program__set_autoload(obj->progs.sched_switch_btf, false);

 	/* initialize global data (filtering options) */
 	obj->rodata->filter_cg = env.cg;
 	obj->rodata->targ_per_process = env.per_process;
 	obj->rodata->targ_per_thread = env.per_thread;
 	obj->rodata->targ_ms = env.milliseconds;
 	obj->rodata->targ_offcpu = env.offcpu;
 	obj->rodata->targ_tgid = env.pid;

 	pid_max = get_pid_max();
 	if (pid_max < 0) {
 		fprintf(stderr, "failed to get pid_max\n");
 		return 1;
 	}

 	bpf_map__set_max_entries(obj->maps.start, pid_max);
 	if (!env.per_process && !env.per_thread)
 		bpf_map__set_max_entries(obj->maps.hists, 1);
 	else
 		bpf_map__set_max_entries(obj->maps.hists, pid_max);

 	err = cpudist_bpf__load(obj);
 	if (err) {
 		fprintf(stderr, "failed to load BPF object: %d\n", err);
 		goto cleanup;
 	}

 	/* update cgroup path fd to map */
 	if (env.cg) {
 		idx = 0;
 		cg_map_fd = bpf_map__fd(obj->maps.cgroup_map);
 		cgfd = open(env.cgroupspath, O_RDONLY);
 		if (cgfd < 0) {
 			fprintf(stderr, "Failed opening Cgroup path: %s", env.cgroupspath);
 			goto cleanup;
 		}
 		if (bpf_map_update_elem(cg_map_fd, &idx, &cgfd, BPF_ANY)) {
 			fprintf(stderr, "Failed adding target cgroup to map");
 			goto cleanup;
 		}
 	}

 	err = cpudist_bpf__attach(obj);
 	if (err) {
 		fprintf(stderr, "failed to attach BPF programs\n");
 		goto cleanup;
 	}

 	fd = bpf_map__fd(obj->maps.hists);

 	signal(SIGINT, sig_handler);

 	printf("Tracing %s-CPU time... Hit Ctrl-C to end.\n", env.offcpu ? "off" : "on");

 	/* main: poll */
 	while (1) {
 		sleep(env.interval);
 		printf("\n");

 		if (env.timestamp) {
 			time(&t);
 			tm = localtime(&t);
 			strftime(ts, sizeof(ts), "%H:%M:%S", tm);
 			printf("%-8s\n", ts);
 		}

 		err = print_log2_hists(fd);
 		if (err)
 			break;

 		if (exiting || --env.times == 0)
 			break;
 	}

 cleanup:
 	cpudist_bpf__destroy(obj);
 	if (cgfd > 0)
 		close(cgfd);

 	return err != 0;
 }
	// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
	// Copyright (c) 2020 Wenbo Zhang
	//
	// Based on cpudist(8) from BCC by Brendan Gregg & Dina Goldshtein.
	// 8-May-2020 Wenbo Zhang Created this.
	#include <argp.h>
	#include <signal.h>
	#include <stdio.h>
	#include <unistd.h>
	#include <time.h>
	#include <fcntl.h>
	#include <bpf/libbpf.h>
	#include <bpf/bpf.h>
	#include "cpudist.h"
	#include "cpudist.skel.h"
	#include "trace_helpers.h"

	static struct env {
	time_t interval;
	pid_t pid;
	char *cgroupspath;
	bool cg;
	int times;
	bool offcpu;
	bool timestamp;
	bool per_process;
	bool per_thread;
	bool milliseconds;
	bool verbose;
	} env = {
	.interval = 99999999,
	.pid = -1,
	.times = 99999999,
	};

	static volatile bool exiting;

	const char *argp_program_version = "cpudist 0.1";
	const char *argp_program_bug_address =
	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
	const char argp_program_doc[] =
	"Summarize on-CPU time per task as a histogram.\n"
	"\n"
	"USAGE: cpudist [--help] [-O] [-T] [-m] [-P] [-L] [-p PID] [interval] [count] [-c CG]\n"
	"\n"
	"EXAMPLES:\n"
	" cpudist # summarize on-CPU time as a histogram"
	" cpudist -O # summarize off-CPU time as a histogram"
	" cpudist -c CG # Trace process under cgroupsPath CG\n"
	" cpudist 1 10 # print 1 second summaries, 10 times"
	" cpudist -mT 1 # 1s summaries, milliseconds, and timestamps"
	" cpudist -P # show each PID separately"
	" cpudist -p 185 # trace PID 185 only";

	static const struct argp_option opts[] = {
	{ "offcpu", 'O', NULL, 0, "Measure off-CPU time" },
	{ "timestamp", 'T', NULL, 0, "Include timestamp on output" },
	{ "milliseconds", 'm', NULL, 0, "Millisecond histogram" },
	{ "cgroup", 'c', "/sys/fs/cgroup/unified", 0, "Trace process in cgroup path" },
	{ "pids", 'P', NULL, 0, "Print a histogram per process ID" },
	{ "tids", 'L', NULL, 0, "Print a histogram per thread ID" },
	{ "pid", 'p', "PID", 0, "Trace this PID only" },
	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
	{},
	};

	static error_t parse_arg(int key, char arg, struct argp_state state)
	{
	static int pos_args;

	switch (key) {
	case 'h':
	argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
	break;
	case 'v':
	env.verbose = true;
	break;
	case 'm':
	env.milliseconds = true;
	break;
	case 'c':
	env.cgroupspath = arg;
	env.cg = true;
	break;
	case 'p':
	errno = 0;
	env.pid = strtol(arg, NULL, 10);
	if (errno) {
	fprintf(stderr, "invalid PID: %s\n", arg);
	argp_usage(state);
	}
	break;
	case 'O':
	env.offcpu = true;
	break;
	case 'P':
	env.per_process = true;
	break;
	case 'L':
	env.per_thread = true;
	break;
	case 'T':
	env.timestamp = true;
	break;
	case ARGP_KEY_ARG:
	errno = 0;
	if (pos_args == 0) {
	env.interval = strtol(arg, NULL, 10);
	if (errno) {
	fprintf(stderr, "invalid internal\n");
	argp_usage(state);
	}
	} else if (pos_args == 1) {
	env.times = strtol(arg, NULL, 10);
	if (errno) {
	fprintf(stderr, "invalid times\n");
	argp_usage(state);
	}
	} else {
	fprintf(stderr,
	"unrecognized positional argument: %s\n", arg);
	argp_usage(state);
	}
	pos_args++;
	break;
	default:
	return ARGP_ERR_UNKNOWN;
	}
	return 0;
	}

	static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
	{
	if (level == LIBBPF_DEBUG && !env.verbose)
	return 0;
	return vfprintf(stderr, format, args);
	}

	static int get_pid_max(void)
	{
	int pid_max;
	FILE *f;

	f = fopen("/proc/sys/kernel/pid_max", "r");
	if (!f)
	return -1;
	if (fscanf(f, "%d\n", &pid_max) != 1)
	pid_max = -1;
	fclose(f);
	return pid_max;
	}

	static void sig_handler(int sig)
	{
	exiting = true;
	}

	static int print_log2_hists(int fd)
	{
	char *units = env.milliseconds ? "msecs" : "usecs";
	__u32 lookup_key = -2, next_key;
	struct hist hist;
	int err;

	while (!bpf_map_get_next_key(fd, &lookup_key, &next_key)) {
	err = bpf_map_lookup_elem(fd, &next_key, &hist);
	if (err < 0) {
	fprintf(stderr, "failed to lookup hist: %d\n", err);
	return -1;
	}
	if (env.per_process)
	printf("\npid = %d %s\n", next_key, hist.comm);
	if (env.per_thread)
	printf("\ntid = %d %s\n", next_key, hist.comm);
	print_log2_hist(hist.slots, MAX_SLOTS, units);
	lookup_key = next_key;
	}

	lookup_key = -2;
	while (!bpf_map_get_next_key(fd, &lookup_key, &next_key)) {
	err = bpf_map_delete_elem(fd, &next_key);
	if (err < 0) {
	fprintf(stderr, "failed to cleanup hist : %d\n", err);
	return -1;
	}
	lookup_key = next_key;
	}
	return 0;
	}

	int main(int argc, char **argv)
	{
	static const struct argp argp = {
	.options = opts,
	.parser = parse_arg,
	.doc = argp_program_doc,
	};
	struct cpudist_bpf *obj;
	int pid_max, fd, err;
	struct tm *tm;
	char ts[32];
	time_t t;
	int idx, cg_map_fd;
	int cgfd = -1;

	err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
	if (err)
	return err;

	libbpf_set_print(libbpf_print_fn);

	obj = cpudist_bpf__open();
	if (!obj) {
	fprintf(stderr, "failed to open BPF object\n");
	return 1;
	}

	if (probe_tp_btf("sched_switch"))
	bpf_program__set_autoload(obj->progs.sched_switch_tp, false);
	else
	bpf_program__set_autoload(obj->progs.sched_switch_btf, false);

	/* initialize global data (filtering options) */
	obj->rodata->filter_cg = env.cg;
	obj->rodata->targ_per_process = env.per_process;
	obj->rodata->targ_per_thread = env.per_thread;
	obj->rodata->targ_ms = env.milliseconds;
	obj->rodata->targ_offcpu = env.offcpu;
	obj->rodata->targ_tgid = env.pid;

	pid_max = get_pid_max();
	if (pid_max < 0) {
	fprintf(stderr, "failed to get pid_max\n");
	return 1;
	}

	bpf_map__set_max_entries(obj->maps.start, pid_max);
	if (!env.per_process && !env.per_thread)
	bpf_map__set_max_entries(obj->maps.hists, 1);
	else
	bpf_map__set_max_entries(obj->maps.hists, pid_max);

	err = cpudist_bpf__load(obj);
	if (err) {
	fprintf(stderr, "failed to load BPF object: %d\n", err);
	goto cleanup;
	}

	/* update cgroup path fd to map */
	if (env.cg) {
	idx = 0;
	cg_map_fd = bpf_map__fd(obj->maps.cgroup_map);
	cgfd = open(env.cgroupspath, O_RDONLY);
	if (cgfd < 0) {
	fprintf(stderr, "Failed opening Cgroup path: %s", env.cgroupspath);
	goto cleanup;
	}
	if (bpf_map_update_elem(cg_map_fd, &idx, &cgfd, BPF_ANY)) {
	fprintf(stderr, "Failed adding target cgroup to map");
	goto cleanup;
	}
	}

	err = cpudist_bpf__attach(obj);
	if (err) {
	fprintf(stderr, "failed to attach BPF programs\n");
	goto cleanup;
	}

	fd = bpf_map__fd(obj->maps.hists);

	signal(SIGINT, sig_handler);

	printf("Tracing %s-CPU time... Hit Ctrl-C to end.\n", env.offcpu ? "off" : "on");

	/* main: poll */
	while (1) {
	sleep(env.interval);
	printf("\n");

	if (env.timestamp) {
	time(&t);
	tm = localtime(&t);
	strftime(ts, sizeof(ts), "%H:%M:%S", tm);
	printf("%-8s\n", ts);
	}

	err = print_log2_hists(fd);
	if (err)
	break;

	if (exiting \|\| --env.times == 0)
	break;
	}

	cleanup:
	cpudist_bpf__destroy(obj);
	if (cgfd > 0)
	close(cgfd);

	return err != 0;
	}