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