xref: /linux/tools/perf/tests/openat-syscall-all-cpus.c (revision 7836e52e518b5e3fd695850f1d4081f756f58406)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <inttypes.h>
4 /* For the CPU_* macros */
5 #include <pthread.h>
6 
7 #include <sys/types.h>
8 #include <sys/stat.h>
9 #include <fcntl.h>
10 #include <api/fs/fs.h>
11 #include <linux/err.h>
12 #include <api/fs/tracing_path.h>
13 #include "evsel.h"
14 #include "tests.h"
15 #include "thread_map.h"
16 #include "cpumap.h"
17 #include "debug.h"
18 #include "stat.h"
19 
20 int test__openat_syscall_event_on_all_cpus(struct test *test __maybe_unused, int subtest __maybe_unused)
21 {
22 	int err = -1, fd, cpu;
23 	struct perf_cpu_map *cpus;
24 	struct evsel *evsel;
25 	unsigned int nr_openat_calls = 111, i;
26 	cpu_set_t cpu_set;
27 	struct perf_thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
28 	char sbuf[STRERR_BUFSIZE];
29 	char errbuf[BUFSIZ];
30 
31 	if (threads == NULL) {
32 		pr_debug("thread_map__new\n");
33 		return -1;
34 	}
35 
36 	cpus = cpu_map__new(NULL);
37 	if (cpus == NULL) {
38 		pr_debug("cpu_map__new\n");
39 		goto out_thread_map_delete;
40 	}
41 
42 	CPU_ZERO(&cpu_set);
43 
44 	evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
45 	if (IS_ERR(evsel)) {
46 		tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
47 		pr_debug("%s\n", errbuf);
48 		goto out_cpu_map_delete;
49 	}
50 
51 	if (evsel__open(evsel, cpus, threads) < 0) {
52 		pr_debug("failed to open counter: %s, "
53 			 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
54 			 str_error_r(errno, sbuf, sizeof(sbuf)));
55 		goto out_evsel_delete;
56 	}
57 
58 	for (cpu = 0; cpu < cpus->nr; ++cpu) {
59 		unsigned int ncalls = nr_openat_calls + cpu;
60 		/*
61 		 * XXX eventually lift this restriction in a way that
62 		 * keeps perf building on older glibc installations
63 		 * without CPU_ALLOC. 1024 cpus in 2010 still seems
64 		 * a reasonable upper limit tho :-)
65 		 */
66 		if (cpus->map[cpu] >= CPU_SETSIZE) {
67 			pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
68 			continue;
69 		}
70 
71 		CPU_SET(cpus->map[cpu], &cpu_set);
72 		if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
73 			pr_debug("sched_setaffinity() failed on CPU %d: %s ",
74 				 cpus->map[cpu],
75 				 str_error_r(errno, sbuf, sizeof(sbuf)));
76 			goto out_close_fd;
77 		}
78 		for (i = 0; i < ncalls; ++i) {
79 			fd = openat(0, "/etc/passwd", O_RDONLY);
80 			close(fd);
81 		}
82 		CPU_CLR(cpus->map[cpu], &cpu_set);
83 	}
84 
85 	/*
86 	 * Here we need to explicitly preallocate the counts, as if
87 	 * we use the auto allocation it will allocate just for 1 cpu,
88 	 * as we start by cpu 0.
89 	 */
90 	if (perf_evsel__alloc_counts(evsel, cpus->nr, 1) < 0) {
91 		pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
92 		goto out_close_fd;
93 	}
94 
95 	err = 0;
96 
97 	for (cpu = 0; cpu < cpus->nr; ++cpu) {
98 		unsigned int expected;
99 
100 		if (cpus->map[cpu] >= CPU_SETSIZE)
101 			continue;
102 
103 		if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
104 			pr_debug("perf_evsel__read_on_cpu\n");
105 			err = -1;
106 			break;
107 		}
108 
109 		expected = nr_openat_calls + cpu;
110 		if (perf_counts(evsel->counts, cpu, 0)->val != expected) {
111 			pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
112 				 expected, cpus->map[cpu], perf_counts(evsel->counts, cpu, 0)->val);
113 			err = -1;
114 		}
115 	}
116 
117 	perf_evsel__free_counts(evsel);
118 out_close_fd:
119 	perf_evsel__close_fd(evsel);
120 out_evsel_delete:
121 	evsel__delete(evsel);
122 out_cpu_map_delete:
123 	perf_cpu_map__put(cpus);
124 out_thread_map_delete:
125 	perf_thread_map__put(threads);
126 	return err;
127 }
128