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Commit | Line | Data |
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ee74701e WN |
1 | /* |
2 | * Test backward bit in event attribute, read ring buffer from end to | |
3 | * beginning | |
4 | */ | |
5 | ||
6 | #include <perf.h> | |
7 | #include <evlist.h> | |
8 | #include <sys/prctl.h> | |
9 | #include "tests.h" | |
10 | #include "debug.h" | |
11 | ||
12 | #define NR_ITERS 111 | |
13 | ||
14 | static void testcase(void) | |
15 | { | |
16 | int i; | |
17 | ||
18 | for (i = 0; i < NR_ITERS; i++) { | |
19 | char proc_name[10]; | |
20 | ||
21 | snprintf(proc_name, sizeof(proc_name), "p:%d\n", i); | |
22 | prctl(PR_SET_NAME, proc_name); | |
23 | } | |
24 | } | |
25 | ||
26 | static int count_samples(struct perf_evlist *evlist, int *sample_count, | |
27 | int *comm_count) | |
28 | { | |
29 | int i; | |
30 | ||
31 | for (i = 0; i < evlist->nr_mmaps; i++) { | |
32 | union perf_event *event; | |
33 | ||
34 | perf_evlist__mmap_read_catchup(evlist, i); | |
35 | while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) { | |
36 | const u32 type = event->header.type; | |
37 | ||
38 | switch (type) { | |
39 | case PERF_RECORD_SAMPLE: | |
40 | (*sample_count)++; | |
41 | break; | |
42 | case PERF_RECORD_COMM: | |
43 | (*comm_count)++; | |
44 | break; | |
45 | default: | |
46 | pr_err("Unexpected record of type %d\n", type); | |
47 | return TEST_FAIL; | |
48 | } | |
49 | } | |
50 | } | |
51 | return TEST_OK; | |
52 | } | |
53 | ||
54 | static int do_test(struct perf_evlist *evlist, int mmap_pages, | |
55 | int *sample_count, int *comm_count) | |
56 | { | |
57 | int err; | |
58 | char sbuf[STRERR_BUFSIZE]; | |
59 | ||
60 | err = perf_evlist__mmap(evlist, mmap_pages, true); | |
61 | if (err < 0) { | |
62 | pr_debug("perf_evlist__mmap: %s\n", | |
63 | strerror_r(errno, sbuf, sizeof(sbuf))); | |
64 | return TEST_FAIL; | |
65 | } | |
66 | ||
67 | perf_evlist__enable(evlist); | |
68 | testcase(); | |
69 | perf_evlist__disable(evlist); | |
70 | ||
71 | err = count_samples(evlist, sample_count, comm_count); | |
72 | perf_evlist__munmap(evlist); | |
73 | return err; | |
74 | } | |
75 | ||
76 | ||
77 | int test__backward_ring_buffer(int subtest __maybe_unused) | |
78 | { | |
79 | int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0; | |
80 | char pid[16], sbuf[STRERR_BUFSIZE]; | |
81 | struct perf_evlist *evlist; | |
82 | struct perf_evsel *evsel __maybe_unused; | |
83 | struct parse_events_error parse_error; | |
84 | struct record_opts opts = { | |
85 | .target = { | |
86 | .uid = UINT_MAX, | |
87 | .uses_mmap = true, | |
88 | }, | |
89 | .freq = 0, | |
90 | .mmap_pages = 256, | |
91 | .default_interval = 1, | |
92 | }; | |
93 | ||
94 | snprintf(pid, sizeof(pid), "%d", getpid()); | |
95 | pid[sizeof(pid) - 1] = '\0'; | |
96 | opts.target.tid = opts.target.pid = pid; | |
97 | ||
98 | evlist = perf_evlist__new(); | |
99 | if (!evlist) { | |
100 | pr_debug("No ehough memory to create evlist\n"); | |
101 | return TEST_FAIL; | |
102 | } | |
103 | ||
104 | err = perf_evlist__create_maps(evlist, &opts.target); | |
105 | if (err < 0) { | |
106 | pr_debug("Not enough memory to create thread/cpu maps\n"); | |
107 | goto out_delete_evlist; | |
108 | } | |
109 | ||
110 | bzero(&parse_error, sizeof(parse_error)); | |
111 | err = parse_events(evlist, "syscalls:sys_enter_prctl", &parse_error); | |
112 | if (err) { | |
113 | pr_debug("Failed to parse tracepoint event, try use root\n"); | |
114 | ret = TEST_SKIP; | |
115 | goto out_delete_evlist; | |
116 | } | |
117 | ||
118 | perf_evlist__config(evlist, &opts, NULL); | |
119 | ||
120 | /* Set backward bit, ring buffer should be writing from end */ | |
e5cadb93 | 121 | evlist__for_each_entry(evlist, evsel) |
ee74701e WN |
122 | evsel->attr.write_backward = 1; |
123 | ||
124 | err = perf_evlist__open(evlist); | |
125 | if (err < 0) { | |
126 | pr_debug("perf_evlist__open: %s\n", | |
127 | strerror_r(errno, sbuf, sizeof(sbuf))); | |
128 | goto out_delete_evlist; | |
129 | } | |
130 | ||
131 | ret = TEST_FAIL; | |
132 | err = do_test(evlist, opts.mmap_pages, &sample_count, | |
133 | &comm_count); | |
134 | if (err != TEST_OK) | |
135 | goto out_delete_evlist; | |
136 | ||
137 | if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) { | |
138 | pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n", | |
139 | sample_count, comm_count); | |
140 | goto out_delete_evlist; | |
141 | } | |
142 | ||
143 | err = do_test(evlist, 1, &sample_count, &comm_count); | |
144 | if (err != TEST_OK) | |
145 | goto out_delete_evlist; | |
146 | ||
147 | ret = TEST_OK; | |
148 | out_delete_evlist: | |
149 | perf_evlist__delete(evlist); | |
150 | return ret; | |
151 | } |