xref: /openbmc/linux/tools/perf/tests/keep-tracking.c (revision e620a1e0)
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 
9 #include "debug.h"
10 #include "parse-events.h"
11 #include "evlist.h"
12 #include "evsel.h"
13 #include "record.h"
14 #include "thread_map.h"
15 #include "tests.h"
16 #include "util/mmap.h"
17 
18 #define CHECK__(x) {				\
19 	while ((x) < 0) {			\
20 		pr_debug(#x " failed!\n");	\
21 		goto out_err;			\
22 	}					\
23 }
24 
25 #define CHECK_NOT_NULL__(x) {			\
26 	while ((x) == NULL) {			\
27 		pr_debug(#x " failed!\n");	\
28 		goto out_err;			\
29 	}					\
30 }
31 
32 static int find_comm(struct evlist *evlist, const char *comm)
33 {
34 	union perf_event *event;
35 	struct mmap *md;
36 	int i, found;
37 
38 	found = 0;
39 	for (i = 0; i < evlist->core.nr_mmaps; i++) {
40 		md = &evlist->mmap[i];
41 		if (perf_mmap__read_init(md) < 0)
42 			continue;
43 		while ((event = perf_mmap__read_event(md)) != NULL) {
44 			if (event->header.type == PERF_RECORD_COMM &&
45 			    (pid_t)event->comm.pid == getpid() &&
46 			    (pid_t)event->comm.tid == getpid() &&
47 			    strcmp(event->comm.comm, comm) == 0)
48 				found += 1;
49 			perf_mmap__consume(md);
50 		}
51 		perf_mmap__read_done(md);
52 	}
53 	return found;
54 }
55 
56 /**
57  * test__keep_tracking - test using a dummy software event to keep tracking.
58  *
59  * This function implements a test that checks that tracking events continue
60  * when an event is disabled but a dummy software event is not disabled.  If the
61  * test passes %0 is returned, otherwise %-1 is returned.
62  */
63 int test__keep_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
64 {
65 	struct record_opts opts = {
66 		.mmap_pages	     = UINT_MAX,
67 		.user_freq	     = UINT_MAX,
68 		.user_interval	     = ULLONG_MAX,
69 		.target		     = {
70 			.uses_mmap   = true,
71 		},
72 	};
73 	struct perf_thread_map *threads = NULL;
74 	struct perf_cpu_map *cpus = NULL;
75 	struct evlist *evlist = NULL;
76 	struct evsel *evsel = NULL;
77 	int found, err = -1;
78 	const char *comm;
79 
80 	threads = thread_map__new(-1, getpid(), UINT_MAX);
81 	CHECK_NOT_NULL__(threads);
82 
83 	cpus = perf_cpu_map__new(NULL);
84 	CHECK_NOT_NULL__(cpus);
85 
86 	evlist = evlist__new();
87 	CHECK_NOT_NULL__(evlist);
88 
89 	perf_evlist__set_maps(&evlist->core, cpus, threads);
90 
91 	CHECK__(parse_events(evlist, "dummy:u", NULL));
92 	CHECK__(parse_events(evlist, "cycles:u", NULL));
93 
94 	perf_evlist__config(evlist, &opts, NULL);
95 
96 	evsel = evlist__first(evlist);
97 
98 	evsel->core.attr.comm = 1;
99 	evsel->core.attr.disabled = 1;
100 	evsel->core.attr.enable_on_exec = 0;
101 
102 	if (evlist__open(evlist) < 0) {
103 		pr_debug("Unable to open dummy and cycles event\n");
104 		err = TEST_SKIP;
105 		goto out_err;
106 	}
107 
108 	CHECK__(evlist__mmap(evlist, UINT_MAX));
109 
110 	/*
111 	 * First, test that a 'comm' event can be found when the event is
112 	 * enabled.
113 	 */
114 
115 	evlist__enable(evlist);
116 
117 	comm = "Test COMM 1";
118 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
119 
120 	evlist__disable(evlist);
121 
122 	found = find_comm(evlist, comm);
123 	if (found != 1) {
124 		pr_debug("First time, failed to find tracking event.\n");
125 		goto out_err;
126 	}
127 
128 	/*
129 	 * Secondly, test that a 'comm' event can be found when the event is
130 	 * disabled with the dummy event still enabled.
131 	 */
132 
133 	evlist__enable(evlist);
134 
135 	evsel = evlist__last(evlist);
136 
137 	CHECK__(evsel__disable(evsel));
138 
139 	comm = "Test COMM 2";
140 	CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
141 
142 	evlist__disable(evlist);
143 
144 	found = find_comm(evlist, comm);
145 	if (found != 1) {
146 		pr_debug("Second time, failed to find tracking event.\n");
147 		goto out_err;
148 	}
149 
150 	err = 0;
151 
152 out_err:
153 	if (evlist) {
154 		evlist__disable(evlist);
155 		evlist__delete(evlist);
156 	} else {
157 		perf_cpu_map__put(cpus);
158 		perf_thread_map__put(threads);
159 	}
160 
161 	return err;
162 }
163