xref: /openbmc/linux/tools/perf/tests/keep-tracking.c (revision 9a6b55ac)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/types.h>
3 #include <limits.h>
4 #include <unistd.h>
5 #include <sys/prctl.h>
6 #include <perf/cpumap.h>
7 #include <perf/evlist.h>
8 #include <perf/mmap.h>
9 
10 #include "debug.h"
11 #include "parse-events.h"
12 #include "evlist.h"
13 #include "evsel.h"
14 #include "record.h"
15 #include "thread_map.h"
16 #include "tests.h"
17 #include "util/mmap.h"
18 
19 #define CHECK__(x) {				\
20 	while ((x) < 0) {			\
21 		pr_debug(#x " failed!\n");	\
22 		goto out_err;			\
23 	}					\
24 }
25 
26 #define CHECK_NOT_NULL__(x) {			\
27 	while ((x) == NULL) {			\
28 		pr_debug(#x " failed!\n");	\
29 		goto out_err;			\
30 	}					\
31 }
32 
33 static int find_comm(struct evlist *evlist, const char *comm)
34 {
35 	union perf_event *event;
36 	struct mmap *md;
37 	int i, found;
38 
39 	found = 0;
40 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
41 		md = &evlist->mmap[i];
42 		if (perf_mmap__read_init(&md->core) < 0)
43 			continue;
44 		while ((event = perf_mmap__read_event(&md->core)) != NULL) {
45 			if (event->header.type == PERF_RECORD_COMM &&
46 			    (pid_t)event->comm.pid == getpid() &&
47 			    (pid_t)event->comm.tid == getpid() &&
48 			    strcmp(event->comm.comm, comm) == 0)
49 				found += 1;
50 			perf_mmap__consume(&md->core);
51 		}
52 		perf_mmap__read_done(&md->core);
53 	}
54 	return found;
55 }
56 
57 /**
58  * test__keep_tracking - test using a dummy software event to keep tracking.
59  *
60  * This function implements a test that checks that tracking events continue
61  * when an event is disabled but a dummy software event is not disabled.  If the
62  * test passes %0 is returned, otherwise %-1 is returned.
63  */
64 int test__keep_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
65 {
66 	struct record_opts opts = {
67 		.mmap_pages	     = UINT_MAX,
68 		.user_freq	     = UINT_MAX,
69 		.user_interval	     = ULLONG_MAX,
70 		.target		     = {
71 			.uses_mmap   = true,
72 		},
73 	};
74 	struct perf_thread_map *threads = NULL;
75 	struct perf_cpu_map *cpus = NULL;
76 	struct evlist *evlist = NULL;
77 	struct evsel *evsel = NULL;
78 	int found, err = -1;
79 	const char *comm;
80 
81 	threads = thread_map__new(-1, getpid(), UINT_MAX);
82 	CHECK_NOT_NULL__(threads);
83 
84 	cpus = perf_cpu_map__new(NULL);
85 	CHECK_NOT_NULL__(cpus);
86 
87 	evlist = evlist__new();
88 	CHECK_NOT_NULL__(evlist);
89 
90 	perf_evlist__set_maps(&evlist->core, cpus, threads);
91 
92 	CHECK__(parse_events(evlist, "dummy:u", NULL));
93 	CHECK__(parse_events(evlist, "cycles:u", NULL));
94 
95 	perf_evlist__config(evlist, &opts, NULL);
96 
97 	evsel = evlist__first(evlist);
98 
99 	evsel->core.attr.comm = 1;
100 	evsel->core.attr.disabled = 1;
101 	evsel->core.attr.enable_on_exec = 0;
102 
103 	if (evlist__open(evlist) < 0) {
104 		pr_debug("Unable to open dummy and cycles event\n");
105 		err = TEST_SKIP;
106 		goto out_err;
107 	}
108 
109 	CHECK__(evlist__mmap(evlist, UINT_MAX));
110 
111 	/*
112 	 * First, test that a 'comm' event can be found when the event is
113 	 * enabled.
114 	 */
115 
116 	evlist__enable(evlist);
117 
118 	comm = "Test COMM 1";
119 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
120 
121 	evlist__disable(evlist);
122 
123 	found = find_comm(evlist, comm);
124 	if (found != 1) {
125 		pr_debug("First time, failed to find tracking event.\n");
126 		goto out_err;
127 	}
128 
129 	/*
130 	 * Secondly, test that a 'comm' event can be found when the event is
131 	 * disabled with the dummy event still enabled.
132 	 */
133 
134 	evlist__enable(evlist);
135 
136 	evsel = evlist__last(evlist);
137 
138 	CHECK__(evsel__disable(evsel));
139 
140 	comm = "Test COMM 2";
141 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
142 
143 	evlist__disable(evlist);
144 
145 	found = find_comm(evlist, comm);
146 	if (found != 1) {
147 		pr_debug("Second time, failed to find tracking event.\n");
148 		goto out_err;
149 	}
150 
151 	err = 0;
152 
153 out_err:
154 	if (evlist) {
155 		evlist__disable(evlist);
156 		evlist__delete(evlist);
157 	} else {
158 		perf_cpu_map__put(cpus);
159 		perf_thread_map__put(threads);
160 	}
161 
162 	return err;
163 }
164