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// 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.user_requested_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);
}
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