perf evlist: No need to do any affinity setup when profiling pids

The cpumap is dummy, so no need to go on figuring out affinity.o

This way we reduce the setup time for simple scenarios like:

	$ perf stat sleep 1

Acked-by: Andi Kleen <[email protected]>
Acked-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: acmel

tools/perf/util/evlist.c

@@ -1290,7 +1290,7 @@ void evlist__close(struct evlist *evlist)
 	 * With perf record core.cpus is usually NULL.
 	 * Use the old method to handle this for now.
 	 */
-	if (!evlist->core.cpus) {
+	if (!evlist->core.cpus || cpu_map__is_dummy(evlist->core.cpus)) {
 		evlist__for_each_entry_reverse(evlist, evsel)
 			evsel__close(evsel);
 		return;