Commit 0a102479 authored by Frederic Weisbecker's avatar Frederic Weisbecker
Browse files

perf: Set filters before mmaping events 



We currently set the filters after we mmap the events, this is a
race that let undesired events record themselves in the buffer before
we had the time to set the filters.

So set the filters before they can be recorded. That also librarizes
the filters setting so that filtering can be done more easily
from other tools than perf record later.

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
parent 5807806a

tools/perf/builtin-record.c

+6 −12
Original line number Diff line number Diff line
@@ -180,12 +180,10 @@ static struct perf_header_attr *get_header_attr(struct perf_event_attr *a, int n 


static void create_counter(struct perf_evsel *evsel, int cpu)

{

	char *filter = evsel->filter;

	struct perf_event_attr *attr = &evsel->attr;

	struct perf_header_attr *h_attr;

	struct perf_sample_id *sid;

	int thread_index;

	int ret;



	for (thread_index = 0; thread_index < evsel_list->threads->nr; thread_index++) {

		h_attr = get_header_attr(attr, evsel->idx);
@@ -204,16 +202,6 @@ static void create_counter(struct perf_evsel *evsel, int cpu) 
			pr_warning("Not enough memory to add id\n");

			exit(-1);

		}



		if (filter != NULL) {

			ret = ioctl(FD(evsel, cpu, thread_index),

				    PERF_EVENT_IOC_SET_FILTER, filter);

			if (ret) {

				error("failed to set filter with %d (%s)\n", errno,

						strerror(errno));

				exit(-1);

			}

		}

	}



	if (!sample_type)
@@ -367,6 +355,12 @@ try_again: 
		}

	}



	if (perf_evlist__set_filters(evlist)) {

		error("failed to set filter with %d (%s)\n", errno,

			strerror(errno));

		exit(-1);

	}



	if (perf_evlist__mmap(evlist, mmap_pages, false) < 0)

		die("failed to mmap with %d (%s)\n", errno, strerror(errno));

tools/perf/util/evlist.c

+28 −0
Original line number Diff line number Diff line
@@ -348,3 +348,31 @@ void perf_evlist__delete_maps(struct perf_evlist *evlist) 
	evlist->cpus	= NULL;

	evlist->threads = NULL;

}



int perf_evlist__set_filters(struct perf_evlist *evlist)

{

	const struct thread_map *threads = evlist->threads;

	const struct cpu_map *cpus = evlist->cpus;

	struct perf_evsel *evsel;

	char *filter;

	int thread;

	int cpu;

	int err;

	int fd;



	list_for_each_entry(evsel, &evlist->entries, node) {

		filter = evsel->filter;

		if (!filter)

			continue;

		for (cpu = 0; cpu < cpus->nr; cpu++) {

			for (thread = 0; thread < threads->nr; thread++) {

				fd = FD(evsel, cpu, thread);

				err = ioctl(fd, PERF_EVENT_IOC_SET_FILTER, filter);

				if (err)

					return err;

			}

		}

	}



	return 0;

}

tools/perf/util/evlist.h

+1 −0
Original line number Diff line number Diff line
@@ -60,5 +60,6 @@ static inline void perf_evlist__set_maps(struct perf_evlist *evlist, 
int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,

			     pid_t target_tid, const char *cpu_list);

void perf_evlist__delete_maps(struct perf_evlist *evlist);

int perf_evlist__set_filters(struct perf_evlist *evlist);



#endif /* __PERF_EVLIST_H */

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