150 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			150 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-only
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| 
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| #include "util/debug.h"
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| #include "util/evlist.h"
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| #include "util/evsel.h"
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| #include "util/mmap.h"
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| #include "util/perf_api_probe.h"
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| #include <perf/mmap.h>
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| #include <linux/perf_event.h>
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| #include <limits.h>
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| #include <pthread.h>
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| #include <sched.h>
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| #include <stdbool.h>
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| 
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| int evlist__add_sb_event(struct evlist *evlist, struct perf_event_attr *attr,
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| 			 evsel__sb_cb_t cb, void *data)
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| {
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| 	struct evsel *evsel;
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| 
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| 	if (!attr->sample_id_all) {
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| 		pr_warning("enabling sample_id_all for all side band events\n");
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| 		attr->sample_id_all = 1;
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| 	}
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| 
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| 	evsel = evsel__new_idx(attr, evlist->core.nr_entries);
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| 	if (!evsel)
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| 		return -1;
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| 
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| 	evsel->side_band.cb = cb;
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| 	evsel->side_band.data = data;
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| 	evlist__add(evlist, evsel);
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| 	return 0;
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| }
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| 
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| static void *perf_evlist__poll_thread(void *arg)
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| {
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| 	struct evlist *evlist = arg;
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| 	bool draining = false;
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| 	int i, done = 0;
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| 	/*
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| 	 * In order to read symbols from other namespaces perf to needs to call
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| 	 * setns(2).  This isn't permitted if the struct_fs has multiple users.
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| 	 * unshare(2) the fs so that we may continue to setns into namespaces
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| 	 * that we're observing when, for instance, reading the build-ids at
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| 	 * the end of a 'perf record' session.
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| 	 */
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| 	unshare(CLONE_FS);
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| 
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| 	while (!done) {
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| 		bool got_data = false;
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| 
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| 		if (evlist->thread.done)
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| 			draining = true;
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| 
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| 		if (!draining)
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| 			evlist__poll(evlist, 1000);
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| 
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| 		for (i = 0; i < evlist->core.nr_mmaps; i++) {
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| 			struct mmap *map = &evlist->mmap[i];
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| 			union perf_event *event;
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| 
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| 			if (perf_mmap__read_init(&map->core))
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| 				continue;
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| 			while ((event = perf_mmap__read_event(&map->core)) != NULL) {
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| 				struct evsel *evsel = evlist__event2evsel(evlist, event);
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| 
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| 				if (evsel && evsel->side_band.cb)
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| 					evsel->side_band.cb(event, evsel->side_band.data);
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| 				else
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| 					pr_warning("cannot locate proper evsel for the side band event\n");
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| 
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| 				perf_mmap__consume(&map->core);
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| 				got_data = true;
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| 			}
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| 			perf_mmap__read_done(&map->core);
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| 		}
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| 
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| 		if (draining && !got_data)
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| 			break;
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| 	}
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| 	return NULL;
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| }
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| 
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| void evlist__set_cb(struct evlist *evlist, evsel__sb_cb_t cb, void *data)
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| {
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| 	struct evsel *evsel;
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| 
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| 	evlist__for_each_entry(evlist, evsel) {
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| 		evsel->core.attr.sample_id_all    = 1;
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| 		evsel->core.attr.watermark        = 1;
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| 		evsel->core.attr.wakeup_watermark = 1;
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| 		evsel->side_band.cb   = cb;
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| 		evsel->side_band.data = data;
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|       }
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| }
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| 
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| int evlist__start_sb_thread(struct evlist *evlist, struct target *target)
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| {
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| 	struct evsel *counter;
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| 
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| 	if (!evlist)
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| 		return 0;
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| 
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| 	if (evlist__create_maps(evlist, target))
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| 		goto out_delete_evlist;
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| 
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| 	if (evlist->core.nr_entries > 1) {
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| 		bool can_sample_identifier = perf_can_sample_identifier();
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| 
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| 		evlist__for_each_entry(evlist, counter)
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| 			evsel__set_sample_id(counter, can_sample_identifier);
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| 
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| 		evlist__set_id_pos(evlist);
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| 	}
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| 
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| 	evlist__for_each_entry(evlist, counter) {
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| 		if (evsel__open(counter, evlist->core.user_requested_cpus,
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| 				evlist->core.threads) < 0)
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| 			goto out_delete_evlist;
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| 	}
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| 
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| 	if (evlist__mmap(evlist, UINT_MAX))
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| 		goto out_delete_evlist;
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| 
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| 	evlist__for_each_entry(evlist, counter) {
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| 		if (evsel__enable(counter))
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| 			goto out_delete_evlist;
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| 	}
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| 
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| 	evlist->thread.done = 0;
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| 	if (pthread_create(&evlist->thread.th, NULL, perf_evlist__poll_thread, evlist))
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| 		goto out_delete_evlist;
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| 
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| 	return 0;
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| 
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| out_delete_evlist:
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| 	evlist__delete(evlist);
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| 	evlist = NULL;
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| 	return -1;
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| }
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| 
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| void evlist__stop_sb_thread(struct evlist *evlist)
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| {
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| 	if (!evlist)
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| 		return;
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| 	evlist->thread.done = 1;
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| 	pthread_join(evlist->thread.th, NULL);
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| 	evlist__delete(evlist);
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| }
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