perf stat: Add branch performance metric

When we count both branches and branch-misses it is useful to
print out the percentage of branch-misses:

 # perf stat -e branches -e branch-misses /bin/true

 Performance counter stats for '/bin/true':

         401684  branches                 #      0.000 M/sec
          23301  branch-misses            #      5.801 %

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: paulus@samba.org
Cc: a.p.zijlstra@chello.nl
LKML-Reference: <20091018112923.GQ4808@kryten>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Anton Blanchard 2009-10-18 22:29:23 +11:00 committed by Ingo Molnar
parent f39cdf25bf
commit 11018201b8

View file

@ -125,6 +125,7 @@ struct stats event_res_stats[MAX_COUNTERS][3];
struct stats runtime_nsecs_stats;
struct stats walltime_nsecs_stats;
struct stats runtime_cycles_stats;
struct stats runtime_branches_stats;
#define MATCH_EVENT(t, c, counter) \
(attrs[counter].type == PERF_TYPE_##t && \
@ -235,6 +236,8 @@ static void read_counter(int counter)
update_stats(&runtime_nsecs_stats, count[0]);
if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))
update_stats(&runtime_cycles_stats, count[0]);
if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))
update_stats(&runtime_branches_stats, count[0]);
}
static int run_perf_stat(int argc __used, const char **argv)
@ -352,6 +355,14 @@ static void abs_printout(int counter, double avg)
ratio = avg / total;
fprintf(stderr, " # %10.3f IPC ", ratio);
} else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter)) {
total = avg_stats(&runtime_branches_stats);
if (total)
ratio = avg * 100 / total;
fprintf(stderr, " # %10.3f %% ", ratio);
} else {
total = avg_stats(&runtime_nsecs_stats);