1 // SPDX-License-Identifier: GPL-2.0
3 * Test backward bit in event attribute, read ring buffer from end to
16 static void testcase(void)
20 for (i = 0; i < NR_ITERS; i++) {
23 snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
24 prctl(PR_SET_NAME, proc_name);
28 static int count_samples(struct perf_evlist *evlist, int *sample_count,
33 for (i = 0; i < evlist->nr_mmaps; i++) {
34 union perf_event *event;
36 perf_mmap__read_catchup(&evlist->backward_mmap[i]);
37 while ((event = perf_mmap__read_backward(&evlist->backward_mmap[i])) != NULL) {
38 const u32 type = event->header.type;
41 case PERF_RECORD_SAMPLE:
44 case PERF_RECORD_COMM:
48 pr_err("Unexpected record of type %d\n", type);
56 static int do_test(struct perf_evlist *evlist, int mmap_pages,
57 int *sample_count, int *comm_count)
60 char sbuf[STRERR_BUFSIZE];
62 err = perf_evlist__mmap(evlist, mmap_pages, true);
64 pr_debug("perf_evlist__mmap: %s\n",
65 str_error_r(errno, sbuf, sizeof(sbuf)));
69 perf_evlist__enable(evlist);
71 perf_evlist__disable(evlist);
73 err = count_samples(evlist, sample_count, comm_count);
74 perf_evlist__munmap(evlist);
79 int test__backward_ring_buffer(struct test *test __maybe_unused, int subtest __maybe_unused)
81 int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
82 char pid[16], sbuf[STRERR_BUFSIZE];
83 struct perf_evlist *evlist;
84 struct perf_evsel *evsel __maybe_unused;
85 struct parse_events_error parse_error;
86 struct record_opts opts = {
93 .default_interval = 1,
96 snprintf(pid, sizeof(pid), "%d", getpid());
97 pid[sizeof(pid) - 1] = '\0';
98 opts.target.tid = opts.target.pid = pid;
100 evlist = perf_evlist__new();
102 pr_debug("Not enough memory to create evlist\n");
106 err = perf_evlist__create_maps(evlist, &opts.target);
108 pr_debug("Not enough memory to create thread/cpu maps\n");
109 goto out_delete_evlist;
112 bzero(&parse_error, sizeof(parse_error));
114 * Set backward bit, ring buffer should be writing from end. Record
117 err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
119 pr_debug("Failed to parse tracepoint event, try use root\n");
121 goto out_delete_evlist;
124 perf_evlist__config(evlist, &opts, NULL);
126 err = perf_evlist__open(evlist);
128 pr_debug("perf_evlist__open: %s\n",
129 str_error_r(errno, sbuf, sizeof(sbuf)));
130 goto out_delete_evlist;
134 err = do_test(evlist, opts.mmap_pages, &sample_count,
137 goto out_delete_evlist;
139 if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
140 pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
141 sample_count, comm_count);
142 goto out_delete_evlist;
145 err = do_test(evlist, 1, &sample_count, &comm_count);
147 goto out_delete_evlist;
151 perf_evlist__delete(evlist);