perf evlist: Introduce set_filter() method

To apply a filter to all the evsels in an evlist.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-v9x3q9rv4caxtox7wtjpchq5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evlist.c

@@ -668,30 +668,37 @@ void perf_evlist__delete_maps(struct perf_evlist *evlist)
 
 int perf_evlist__apply_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;
+	int err = 0;
+	const int ncpus = cpu_map__nr(evlist->cpus),
+		  nthreads = evlist->threads->nr;
 
 	list_for_each_entry(evsel, &evlist->entries, node) {
-		filter = evsel->filter;
-		if (!filter)
+		if (evsel->filter == NULL)
 			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;
-			}
-		}
+
+		err = perf_evsel__set_filter(evsel, ncpus, nthreads, evsel->filter);
+		if (err)
+			break;
 	}
 
-	return 0;
+	return err;
+}
+
+int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
+{
+	struct perf_evsel *evsel;
+	int err = 0;
+	const int ncpus = cpu_map__nr(evlist->cpus),
+		  nthreads = evlist->threads->nr;
+
+	list_for_each_entry(evsel, &evlist->entries, node) {
+		err = perf_evsel__set_filter(evsel, ncpus, nthreads, filter);
+		if (err)
+			break;
+	}
+
+	return err;
 }
 
 bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)

tools/perf/util/evlist.h

@@ -72,6 +72,8 @@ int perf_evlist__set_tracepoints_handlers(struct perf_evlist *evlist,
 #define perf_evlist__set_tracepoints_handlers_array(evlist, array) \
 	perf_evlist__set_tracepoints_handlers(evlist, array, ARRAY_SIZE(array))
 
+int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter);
+
 struct perf_evsel *
 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id);
 

tools/perf/util/evsel.c

@@ -505,6 +505,24 @@ int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
 	return evsel->fd != NULL ? 0 : -ENOMEM;
 }
 
+int perf_evsel__set_filter(struct perf_evsel *evsel, int ncpus, int nthreads,
+			   const char *filter)
+{
+	int cpu, thread;
+
+	for (cpu = 0; cpu < ncpus; cpu++) {
+		for (thread = 0; thread < nthreads; thread++) {
+			int fd = FD(evsel, cpu, thread),
+			    err = ioctl(fd, PERF_EVENT_IOC_SET_FILTER, filter);
+
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
 {
 	evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));

tools/perf/util/evsel.h

@@ -115,6 +115,9 @@ void perf_evsel__free_fd(struct perf_evsel *evsel);
 void perf_evsel__free_id(struct perf_evsel *evsel);
 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads);
 
+int perf_evsel__set_filter(struct perf_evsel *evsel, int ncpus, int nthreads,
+			   const char *filter);
+
 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
 			     struct cpu_map *cpus);
 int perf_evsel__open_per_thread(struct perf_evsel *evsel,