diff options
Diffstat (limited to '')
-rw-r--r-- | tools/perf/util/sideband_evlist.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/tools/perf/util/sideband_evlist.c b/tools/perf/util/sideband_evlist.c new file mode 100644 index 000000000..ded9ced02 --- /dev/null +++ b/tools/perf/util/sideband_evlist.c @@ -0,0 +1,148 @@ +// 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 perf_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 = perf_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 perf_evlist__start_sb_thread(struct evlist *evlist, struct target *target) +{ + struct evsel *counter; + + if (!evlist) + return 0; + + if (perf_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); + + perf_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 perf_evlist__stop_sb_thread(struct evlist *evlist) +{ + if (!evlist) + return; + evlist->thread.done = 1; + pthread_join(evlist->thread.th, NULL); + evlist__delete(evlist); +} |