1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | |
3 | #include "util/debug.h" |
4 | #include "util/evlist.h" |
5 | #include "util/evsel.h" |
6 | #include "util/mmap.h" |
7 | #include "util/perf_api_probe.h" |
8 | #include <perf/mmap.h> |
9 | #include <linux/perf_event.h> |
10 | #include <limits.h> |
11 | #include <pthread.h> |
12 | #include <sched.h> |
13 | #include <stdbool.h> |
14 | |
15 | int evlist__add_sb_event(struct evlist *evlist, struct perf_event_attr *attr, |
16 | evsel__sb_cb_t cb, void *data) |
17 | { |
18 | struct evsel *evsel; |
19 | |
20 | if (!attr->sample_id_all) { |
21 | pr_warning("enabling sample_id_all for all side band events\n" ); |
22 | attr->sample_id_all = 1; |
23 | } |
24 | |
25 | evsel = evsel__new_idx(attr, evlist->core.nr_entries); |
26 | if (!evsel) |
27 | return -1; |
28 | |
29 | evsel->side_band.cb = cb; |
30 | evsel->side_band.data = data; |
31 | evlist__add(evlist, evsel); |
32 | return 0; |
33 | } |
34 | |
35 | static void *perf_evlist__poll_thread(void *arg) |
36 | { |
37 | struct evlist *evlist = arg; |
38 | bool draining = false; |
39 | int i, done = 0; |
40 | /* |
41 | * In order to read symbols from other namespaces perf to needs to call |
42 | * setns(2). This isn't permitted if the struct_fs has multiple users. |
43 | * unshare(2) the fs so that we may continue to setns into namespaces |
44 | * that we're observing when, for instance, reading the build-ids at |
45 | * the end of a 'perf record' session. |
46 | */ |
47 | unshare(CLONE_FS); |
48 | |
49 | while (!done) { |
50 | bool got_data = false; |
51 | |
52 | if (evlist->thread.done) |
53 | draining = true; |
54 | |
55 | if (!draining) |
56 | evlist__poll(evlist, 1000); |
57 | |
58 | for (i = 0; i < evlist->core.nr_mmaps; i++) { |
59 | struct mmap *map = &evlist->mmap[i]; |
60 | union perf_event *event; |
61 | |
62 | if (perf_mmap__read_init(&map->core)) |
63 | continue; |
64 | while ((event = perf_mmap__read_event(&map->core)) != NULL) { |
65 | struct evsel *evsel = evlist__event2evsel(evlist, event); |
66 | |
67 | if (evsel && evsel->side_band.cb) |
68 | evsel->side_band.cb(event, evsel->side_band.data); |
69 | else |
70 | pr_warning("cannot locate proper evsel for the side band event\n" ); |
71 | |
72 | perf_mmap__consume(&map->core); |
73 | got_data = true; |
74 | } |
75 | perf_mmap__read_done(&map->core); |
76 | } |
77 | |
78 | if (draining && !got_data) |
79 | break; |
80 | } |
81 | return NULL; |
82 | } |
83 | |
84 | void evlist__set_cb(struct evlist *evlist, evsel__sb_cb_t cb, void *data) |
85 | { |
86 | struct evsel *evsel; |
87 | |
88 | evlist__for_each_entry(evlist, evsel) { |
89 | evsel->core.attr.sample_id_all = 1; |
90 | evsel->core.attr.watermark = 1; |
91 | evsel->core.attr.wakeup_watermark = 1; |
92 | evsel->side_band.cb = cb; |
93 | evsel->side_band.data = data; |
94 | } |
95 | } |
96 | |
97 | int evlist__start_sb_thread(struct evlist *evlist, struct target *target) |
98 | { |
99 | struct evsel *counter; |
100 | |
101 | if (!evlist) |
102 | return 0; |
103 | |
104 | if (evlist__create_maps(evlist, target)) |
105 | goto out_delete_evlist; |
106 | |
107 | if (evlist->core.nr_entries > 1) { |
108 | bool can_sample_identifier = perf_can_sample_identifier(); |
109 | |
110 | evlist__for_each_entry(evlist, counter) |
111 | evsel__set_sample_id(counter, can_sample_identifier); |
112 | |
113 | evlist__set_id_pos(evlist); |
114 | } |
115 | |
116 | evlist__for_each_entry(evlist, counter) { |
117 | if (evsel__open(counter, evlist->core.user_requested_cpus, |
118 | evlist->core.threads) < 0) |
119 | goto out_delete_evlist; |
120 | } |
121 | |
122 | if (evlist__mmap(evlist, UINT_MAX)) |
123 | goto out_delete_evlist; |
124 | |
125 | evlist__for_each_entry(evlist, counter) { |
126 | if (evsel__enable(counter)) |
127 | goto out_delete_evlist; |
128 | } |
129 | |
130 | evlist->thread.done = 0; |
131 | if (pthread_create(&evlist->thread.th, NULL, perf_evlist__poll_thread, evlist)) |
132 | goto out_delete_evlist; |
133 | |
134 | return 0; |
135 | |
136 | out_delete_evlist: |
137 | evlist__delete(evlist); |
138 | evlist = NULL; |
139 | return -1; |
140 | } |
141 | |
142 | void evlist__stop_sb_thread(struct evlist *evlist) |
143 | { |
144 | if (!evlist) |
145 | return; |
146 | evlist->thread.done = 1; |
147 | pthread_join(evlist->thread.th, NULL); |
148 | evlist__delete(evlist); |
149 | } |
150 | |