xref: /linux/tools/perf/tests/keep-tracking.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/types.h>
3 #include <unistd.h>
4 #include <sys/prctl.h>
5 
6 #include "parse-events.h"
7 #include "evlist.h"
8 #include "evsel.h"
9 #include "thread_map.h"
10 #include "cpumap.h"
11 #include "tests.h"
12 
13 #define CHECK__(x) {				\
14 	while ((x) < 0) {			\
15 		pr_debug(#x " failed!\n");	\
16 		goto out_err;			\
17 	}					\
18 }
19 
20 #define CHECK_NOT_NULL__(x) {			\
21 	while ((x) == NULL) {			\
22 		pr_debug(#x " failed!\n");	\
23 		goto out_err;			\
24 	}					\
25 }
26 
27 static int find_comm(struct perf_evlist *evlist, const char *comm)
28 {
29 	union perf_event *event;
30 	struct perf_mmap *md;
31 	int i, found;
32 
33 	found = 0;
34 	for (i = 0; i < evlist->nr_mmaps; i++) {
35 		md = &evlist->mmap[i];
36 		if (perf_mmap__read_init(md) < 0)
37 			continue;
38 		while ((event = perf_mmap__read_event(md)) != NULL) {
39 			if (event->header.type == PERF_RECORD_COMM &&
40 			    (pid_t)event->comm.pid == getpid() &&
41 			    (pid_t)event->comm.tid == getpid() &&
42 			    strcmp(event->comm.comm, comm) == 0)
43 				found += 1;
44 			perf_mmap__consume(md);
45 		}
46 		perf_mmap__read_done(md);
47 	}
48 	return found;
49 }
50 
51 /**
52  * test__keep_tracking - test using a dummy software event to keep tracking.
53  *
54  * This function implements a test that checks that tracking events continue
55  * when an event is disabled but a dummy software event is not disabled.  If the
56  * test passes %0 is returned, otherwise %-1 is returned.
57  */
58 int test__keep_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
59 {
60 	struct record_opts opts = {
61 		.mmap_pages	     = UINT_MAX,
62 		.user_freq	     = UINT_MAX,
63 		.user_interval	     = ULLONG_MAX,
64 		.target		     = {
65 			.uses_mmap   = true,
66 		},
67 	};
68 	struct thread_map *threads = NULL;
69 	struct cpu_map *cpus = NULL;
70 	struct perf_evlist *evlist = NULL;
71 	struct perf_evsel *evsel = NULL;
72 	int found, err = -1;
73 	const char *comm;
74 
75 	threads = thread_map__new(-1, getpid(), UINT_MAX);
76 	CHECK_NOT_NULL__(threads);
77 
78 	cpus = cpu_map__new(NULL);
79 	CHECK_NOT_NULL__(cpus);
80 
81 	evlist = perf_evlist__new();
82 	CHECK_NOT_NULL__(evlist);
83 
84 	perf_evlist__set_maps(evlist, cpus, threads);
85 
86 	CHECK__(parse_events(evlist, "dummy:u", NULL));
87 	CHECK__(parse_events(evlist, "cycles:u", NULL));
88 
89 	perf_evlist__config(evlist, &opts, NULL);
90 
91 	evsel = perf_evlist__first(evlist);
92 
93 	evsel->attr.comm = 1;
94 	evsel->attr.disabled = 1;
95 	evsel->attr.enable_on_exec = 0;
96 
97 	if (perf_evlist__open(evlist) < 0) {
98 		pr_debug("Unable to open dummy and cycles event\n");
99 		err = TEST_SKIP;
100 		goto out_err;
101 	}
102 
103 	CHECK__(perf_evlist__mmap(evlist, UINT_MAX));
104 
105 	/*
106 	 * First, test that a 'comm' event can be found when the event is
107 	 * enabled.
108 	 */
109 
110 	perf_evlist__enable(evlist);
111 
112 	comm = "Test COMM 1";
113 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
114 
115 	perf_evlist__disable(evlist);
116 
117 	found = find_comm(evlist, comm);
118 	if (found != 1) {
119 		pr_debug("First time, failed to find tracking event.\n");
120 		goto out_err;
121 	}
122 
123 	/*
124 	 * Secondly, test that a 'comm' event can be found when the event is
125 	 * disabled with the dummy event still enabled.
126 	 */
127 
128 	perf_evlist__enable(evlist);
129 
130 	evsel = perf_evlist__last(evlist);
131 
132 	CHECK__(perf_evsel__disable(evsel));
133 
134 	comm = "Test COMM 2";
135 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
136 
137 	perf_evlist__disable(evlist);
138 
139 	found = find_comm(evlist, comm);
140 	if (found != 1) {
141 		pr_debug("Seconf time, failed to find tracking event.\n");
142 		goto out_err;
143 	}
144 
145 	err = 0;
146 
147 out_err:
148 	if (evlist) {
149 		perf_evlist__disable(evlist);
150 		perf_evlist__delete(evlist);
151 	} else {
152 		cpu_map__put(cpus);
153 		thread_map__put(threads);
154 	}
155 
156 	return err;
157 }
158