1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2016 Facebook
  3 */
  4#define _GNU_SOURCE
  5#include <sched.h>
  6#include <errno.h>
  7#include <stdio.h>
  8#include <sys/types.h>
  9#include <asm/unistd.h>
 10#include <fcntl.h>
 11#include <unistd.h>
 12#include <assert.h>
 13#include <sys/wait.h>
 14#include <stdlib.h>
 15#include <signal.h>
 16#include <linux/bpf.h>
 17#include <string.h>
 18#include <time.h>
 19#include <sys/resource.h>
 20#include <bpf/bpf.h>
 21#include <bpf/libbpf.h>
 22
 23#define MAX_CNT 1000000
 24
 25static struct bpf_link *links[2];
 26static struct bpf_object *obj;
 27static int cnt;
 28
 29static __u64 time_get_ns(void)
 30{
 31	struct timespec ts;
 32
 33	clock_gettime(CLOCK_MONOTONIC, &ts);
 34	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
 35}
 36
 37static void test_task_rename(int cpu)
 38{
 39	__u64 start_time;
 40	char buf[] = "test\n";
 41	int i, fd;
 42
 43	fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
 44	if (fd < 0) {
 45		printf("couldn't open /proc\n");
 46		exit(1);
 47	}
 48	start_time = time_get_ns();
 49	for (i = 0; i < MAX_CNT; i++) {
 50		if (write(fd, buf, sizeof(buf)) < 0) {
 51			printf("task rename failed: %s\n", strerror(errno));
 52			close(fd);
 53			return;
 54		}
 55	}
 56	printf("task_rename:%d: %lld events per sec\n",
 57	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
 58	close(fd);
 59}
 60
 61static void test_urandom_read(int cpu)
 62{
 63	__u64 start_time;
 64	char buf[4];
 65	int i, fd;
 66
 67	fd = open("/dev/urandom", O_RDONLY);
 68	if (fd < 0) {
 69		printf("couldn't open /dev/urandom\n");
 70		exit(1);
 71	}
 72	start_time = time_get_ns();
 73	for (i = 0; i < MAX_CNT; i++) {
 74		if (read(fd, buf, sizeof(buf)) < 0) {
 75			printf("failed to read from /dev/urandom: %s\n", strerror(errno));
 76			close(fd);
 77			return;
 78		}
 79	}
 80	printf("urandom_read:%d: %lld events per sec\n",
 81	       cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
 82	close(fd);
 83}
 84
 85static void loop(int cpu, int flags)
 86{
 87	cpu_set_t cpuset;
 88
 89	CPU_ZERO(&cpuset);
 90	CPU_SET(cpu, &cpuset);
 91	sched_setaffinity(0, sizeof(cpuset), &cpuset);
 92
 93	if (flags & 1)
 94		test_task_rename(cpu);
 95	if (flags & 2)
 96		test_urandom_read(cpu);
 97}
 98
 99static void run_perf_test(int tasks, int flags)
100{
101	pid_t pid[tasks];
102	int i;
103
104	for (i = 0; i < tasks; i++) {
105		pid[i] = fork();
106		if (pid[i] == 0) {
107			loop(i, flags);
108			exit(0);
109		} else if (pid[i] == -1) {
110			printf("couldn't spawn #%d process\n", i);
111			exit(1);
112		}
113	}
114	for (i = 0; i < tasks; i++) {
115		int status;
116
117		assert(waitpid(pid[i], &status, 0) == pid[i]);
118		assert(status == 0);
119	}
120}
121
122static int load_progs(char *filename)
123{
124	struct bpf_program *prog;
125	int err = 0;
126
127	obj = bpf_object__open_file(filename, NULL);
128	err = libbpf_get_error(obj);
129	if (err < 0) {
130		fprintf(stderr, "ERROR: opening BPF object file failed\n");
131		return err;
132	}
133
134	/* load BPF program */
135	err = bpf_object__load(obj);
136	if (err < 0) {
137		fprintf(stderr, "ERROR: loading BPF object file failed\n");
138		return err;
139	}
140
141	bpf_object__for_each_program(prog, obj) {
142		links[cnt] = bpf_program__attach(prog);
143		err = libbpf_get_error(links[cnt]);
144		if (err < 0) {
145			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
146			links[cnt] = NULL;
147			return err;
148		}
149		cnt++;
150	}
151
152	return err;
153}
154
155static void unload_progs(void)
156{
157	while (cnt)
158		bpf_link__destroy(links[--cnt]);
159
160	bpf_object__close(obj);
161}
162
163int main(int argc, char **argv)
164{
165	int num_cpu = sysconf(_SC_NPROCESSORS_ONLN);
166	int test_flags = ~0;
167	char filename[256];
168	int err = 0;
169
170
171	if (argc > 1)
172		test_flags = atoi(argv[1]) ? : test_flags;
173	if (argc > 2)
174		num_cpu = atoi(argv[2]) ? : num_cpu;
175
176	if (test_flags & 0x3) {
177		printf("BASE\n");
178		run_perf_test(num_cpu, test_flags);
179	}
180
181	if (test_flags & 0xC) {
182		snprintf(filename, sizeof(filename),
183			 "%s_kprobe_kern.o", argv[0]);
184
185		printf("w/KPROBE\n");
186		err = load_progs(filename);
187		if (!err)
188			run_perf_test(num_cpu, test_flags >> 2);
189
190		unload_progs();
191	}
192
193	if (test_flags & 0x30) {
194		snprintf(filename, sizeof(filename),
195			 "%s_tp_kern.o", argv[0]);
196		printf("w/TRACEPOINT\n");
197		err = load_progs(filename);
198		if (!err)
199			run_perf_test(num_cpu, test_flags >> 4);
200
201		unload_progs();
202	}
203
204	if (test_flags & 0xC0) {
205		snprintf(filename, sizeof(filename),
206			 "%s_raw_tp_kern.o", argv[0]);
207		printf("w/RAW_TRACEPOINT\n");
208		err = load_progs(filename);
209		if (!err)
210			run_perf_test(num_cpu, test_flags >> 6);
211
212		unload_progs();
213	}
214
215	return err;
216}