perf evlist: Return the first evsel with an invalid filter in apply_filters()

Use of a bad filter currently generates the message:
 Error: failed to set filter with 22 (Invalid argument)

Add the event name to make it clear to which event the filter
failed to apply:
  Error: Failed to set filter "foo" on event sched:sg_lb_stats: 22: Invalid argument

To test it use something like:

 # perf record -e sched:sched_switch -e sched:*fork --filter parent_pid==1 -e sched:*wait* --filter bla usleep 1
  Error: failed to set filter "bla" on event sched:sched_stat_iowait with 22 (Invalid argument)
 #

Based-on-a-patch-by: David Ahern <dsahern@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-d7gq2fjvaecozp9o2i0siifu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -161,8 +161,9 @@ try_again:
 		}
 	}
 
-	if (perf_evlist__apply_filters(evlist)) {
-		error("failed to set filter with %d (%s)\n", errno,
+	if (perf_evlist__apply_filters(evlist, &pos)) {
+		error("failed to set filter \"%s\" on event %s with %d (%s)\n",
+			pos->filter, perf_evsel__name(pos), errno,
 			strerror_r(errno, msg, sizeof(msg)));
 		rc = -1;
 		goto out;

tools/perf/builtin-stat.c

@@ -684,8 +684,9 @@ static int __run_perf_stat(int argc, const char **argv)
 			unit_width = l;
 	}
 
-	if (perf_evlist__apply_filters(evsel_list)) {
-		error("failed to set filter with %d (%s)\n", errno,
+	if (perf_evlist__apply_filters(evsel_list, &counter)) {
+		error("failed to set filter \"%s\" on event %s with %d (%s)\n",
+			counter->filter, perf_evsel__name(counter), errno,
 			strerror_r(errno, msg, sizeof(msg)));
 		return -1;
 	}

tools/perf/util/evlist.c

@@ -1050,7 +1050,7 @@ out_delete_threads:
 	return -1;
 }
 
-int perf_evlist__apply_filters(struct perf_evlist *evlist)
+int perf_evlist__apply_filters(struct perf_evlist *evlist, struct perf_evsel **err_evsel)
 {
 	struct perf_evsel *evsel;
 	int err = 0;
@@ -1062,8 +1062,10 @@ int perf_evlist__apply_filters(struct perf_evlist *evlist)
 			continue;
 
 		err = perf_evsel__set_filter(evsel, ncpus, nthreads, evsel->filter);
-		if (err)
+		if (err) {
+			*err_evsel = evsel;
 			break;
+		}
 	}
 
 	return err;

tools/perf/util/evlist.h

@@ -152,7 +152,7 @@ static inline void perf_evlist__set_maps(struct perf_evlist *evlist,
 }
 
 int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target);
-int perf_evlist__apply_filters(struct perf_evlist *evlist);
+int perf_evlist__apply_filters(struct perf_evlist *evlist, struct perf_evsel **err_evsel);
 
 void __perf_evlist__set_leader(struct list_head *list);
 void perf_evlist__set_leader(struct perf_evlist *evlist);