tools/testing/selftests/bpf/prog_tests/test_overhead.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2019 Facebook */
   3 #define _GNU_SOURCE
   4 #include <sched.h>
   5 #include <test_progs.h>
   6
   7 #define MAX_CNT 100000
   8
   9 static __u64 time_get_ns(void)
  10 {
  11         struct timespec ts;
  12
  13         clock_gettime(CLOCK_MONOTONIC, &ts);
  14         return ts.tv_sec * 1000000000ull + ts.tv_nsec;
  15 }
  16
  17 static int test_task_rename(const char *prog)
  18 {
  19         int i, fd, duration = 0, err;
  20         char buf[] = "test\n";
  21         __u64 start_time;
  22
  23         fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
  24         if (CHECK(fd < 0, "open /proc", "err %d", errno))
  25                 return -1;
  26         start_time = time_get_ns();
  27         for (i = 0; i < MAX_CNT; i++) {
  28                 err = write(fd, buf, sizeof(buf));
  29                 if (err < 0) {
  30                         CHECK(err < 0, "task rename", "err %d", errno);
  31                         close(fd);
  32                         return -1;
  33                 }
  34         }
  35         printf("task_rename %s\t%lluK events per sec\n", prog,
  36                MAX_CNT * 1000000ll / (time_get_ns() - start_time));
  37         close(fd);
  38         return 0;
  39 }
  40
  41 static void test_run(const char *prog)
  42 {
  43         test_task_rename(prog);
  44 }
  45
  46 static void setaffinity(void)
  47 {
  48         cpu_set_t cpuset;
  49         int cpu = 0;
  50
  51         CPU_ZERO(&cpuset);
  52         CPU_SET(cpu, &cpuset);
  53         sched_setaffinity(0, sizeof(cpuset), &cpuset);
  54 }
  55
  56 void test_test_overhead(void)
  57 {
  58         const char *kprobe_name = "kprobe/__set_task_comm";
  59         const char *kretprobe_name = "kretprobe/__set_task_comm";
  60         const char *raw_tp_name = "raw_tp/task_rename";
  61         const char *fentry_name = "fentry/__set_task_comm";
  62         const char *fexit_name = "fexit/__set_task_comm";
  63         const char *kprobe_func = "__set_task_comm";
  64         struct bpf_program *kprobe_prog, *kretprobe_prog, *raw_tp_prog;
  65         struct bpf_program *fentry_prog, *fexit_prog;
  66         struct bpf_object *obj;
  67         struct bpf_link *link;
  68         int err, duration = 0;
  69
  70         obj = bpf_object__open_file("./test_overhead.o", NULL);
  71         if (CHECK(IS_ERR(obj), "obj_open_file", "err %ld\n", PTR_ERR(obj)))
  72                 return;
  73
  74         kprobe_prog = bpf_object__find_program_by_title(obj, kprobe_name);
  75         if (CHECK(!kprobe_prog, "find_probe",
  76                   "prog '%s' not found\n", kprobe_name))
  77                 goto cleanup;
  78         kretprobe_prog = bpf_object__find_program_by_title(obj, kretprobe_name);
  79         if (CHECK(!kretprobe_prog, "find_probe",
  80                   "prog '%s' not found\n", kretprobe_name))
  81                 goto cleanup;
  82         raw_tp_prog = bpf_object__find_program_by_title(obj, raw_tp_name);
  83         if (CHECK(!raw_tp_prog, "find_probe",
  84                   "prog '%s' not found\n", raw_tp_name))
  85                 goto cleanup;
  86         fentry_prog = bpf_object__find_program_by_title(obj, fentry_name);
  87         if (CHECK(!fentry_prog, "find_probe",
  88                   "prog '%s' not found\n", fentry_name))
  89                 goto cleanup;
  90         fexit_prog = bpf_object__find_program_by_title(obj, fexit_name);
  91         if (CHECK(!fexit_prog, "find_probe",
  92                   "prog '%s' not found\n", fexit_name))
  93                 goto cleanup;
  94
  95         err = bpf_object__load(obj);
  96         if (CHECK(err, "obj_load", "err %d\n", err))
  97                 goto cleanup;
  98
  99         setaffinity();
 100
 101         /* base line run */
 102         test_run("base");
 103
 104         /* attach kprobe */
 105         link = bpf_program__attach_kprobe(kprobe_prog, false /* retprobe */,
 106                                           kprobe_func);
 107         if (CHECK(IS_ERR(link), "attach_kprobe", "err %ld\n", PTR_ERR(link)))
 108                 goto cleanup;
 109         test_run("kprobe");
 110         bpf_link__destroy(link);
 111
 112         /* attach kretprobe */
 113         link = bpf_program__attach_kprobe(kretprobe_prog, true /* retprobe */,
 114                                           kprobe_func);
 115         if (CHECK(IS_ERR(link), "attach kretprobe", "err %ld\n", PTR_ERR(link)))
 116                 goto cleanup;
 117         test_run("kretprobe");
 118         bpf_link__destroy(link);
 119
 120         /* attach raw_tp */
 121         link = bpf_program__attach_raw_tracepoint(raw_tp_prog, "task_rename");
 122         if (CHECK(IS_ERR(link), "attach fentry", "err %ld\n", PTR_ERR(link)))
 123                 goto cleanup;
 124         test_run("raw_tp");
 125         bpf_link__destroy(link);
 126
 127         /* attach fentry */
 128         link = bpf_program__attach_trace(fentry_prog);
 129         if (CHECK(IS_ERR(link), "attach fentry", "err %ld\n", PTR_ERR(link)))
 130                 goto cleanup;
 131         test_run("fentry");
 132         bpf_link__destroy(link);
 133
 134         /* attach fexit */
 135         link = bpf_program__attach_trace(fexit_prog);
 136         if (CHECK(IS_ERR(link), "attach fexit", "err %ld\n", PTR_ERR(link)))
 137                 goto cleanup;
 138         test_run("fexit");
 139         bpf_link__destroy(link);
 140 cleanup:
 141         bpf_object__close(obj);
 142 }