perf_counter tools: Print 'CPU utilization factor' in builtin-stat

Before:

 Performance counter stats for '/home/mingo/hackbench':

    5728.862689  task clock ticks     (msecs)
          34426  context switches     #        0.006 M/sec
           3835  CPU migrations       #        0.001 M/sec
          18158  pagefaults           #        0.003 M/sec
    16218109156  CPU cycles           #     2830.947 M/sec
    13519616840  instructions         #     2359.913 M/sec
       55941661  cache references     #        9.765 M/sec
       23554938  cache misses         #        4.112 M/sec

 Wall-clock time elapsed:   528.886980 msecs

After:

 Performance counter stats for '/home/mingo/hackbench':

    5845.443541  task clock ticks     #      11.886 CPU utilization factor
          38289  context switches     #       0.007 M/sec
           4208  CPU migrations       #       0.001 M/sec
          17755  pagefaults           #       0.003 M/sec
    16664668576  CPU cycles           #    2850.882 M/sec
    13468113991  instructions         #    2304.036 M/sec
       57445468  cache references     #       9.827 M/sec
       26896502  cache misses         #       4.601 M/sec

 Wall-clock time elapsed:   491.802357 msecs

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Documentation/perf_counter/builtin-stat.c

@@ -75,6 +75,7 @@ static __u64			event_res[MAX_COUNTERS][3];
 static __u64			event_scaled[MAX_COUNTERS];
 
 static __u64			runtime_nsecs;
+static __u64			walltime_nsecs;
 
 static void create_perfstat_counter(int counter)
 {
@@ -194,13 +195,19 @@ static void print_counter(int counter)
 	if (nsec_counter(counter)) {
 		double msecs = (double)count[0] / 1000000;
 
-		fprintf(stderr, " %14.6f  %-20s (msecs)",
+		fprintf(stderr, " %14.6f  %-20s",
 			msecs, event_name(counter));
+		if (event_id[counter] ==
+				EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK)) {
+
+			fprintf(stderr, " # %11.3f CPU utilization factor",
+				(double)count[0] / (double)walltime_nsecs);
+		}
 	} else {
 		fprintf(stderr, " %14Ld  %-20s",
 			count[0], event_name(counter));
 		if (runtime_nsecs)
-			fprintf(stderr, " # %12.3f M/sec",
+			fprintf(stderr, " # %11.3f M/sec",
 				(double)count[0]/runtime_nsecs*1000.0);
 	}
 	if (scaled)
@@ -241,6 +248,8 @@ static int do_perfstat(int argc, const char **argv)
 	prctl(PR_TASK_PERF_COUNTERS_DISABLE);
 	t1 = rdclock();
 
+	walltime_nsecs = t1 - t0;
+
 	fflush(stdout);
 
 	fprintf(stderr, "\n");