perf evlist: Add thread_map__nr() helper

Introduce and use the thread_map__nr() function to protect a possible
NULL pointer dereference and cleanup the code a bit.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1362987798-24969-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 020329dca005..20ffaf98782e 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -249,7 +249,7 @@ static int read_counter_aggr(struct perf_evsel *counter)
         int i;
 
         if (__perf_evsel__read(counter, perf_evsel__nr_cpus(counter),
-                               evsel_list->threads->nr, scale) < 0)
+                               thread_map__nr(evsel_list->threads), scale) < 0)
                 return -1;
 
         for (i = 0; i < 3; i++)
@@ -488,7 +488,7 @@ static int __run_perf_stat(int argc __maybe_unused, const char **argv)
                 list_for_each_entry(counter, &evsel_list->entries, node) {
                         read_counter_aggr(counter);
                         perf_evsel__close_fd(counter, perf_evsel__nr_cpus(counter),
-                                             evsel_list->threads->nr);
+                                             thread_map__nr(evsel_list->threads));
                 }
         }