perf stat: Fix verbose for perf stat

Error message should use stderr for verbose (-v), otherwise
message will be lost for:

 $ ./perf stat -v <cmd>  > /dev/null

For example on AMD bus-cycles event is not available so now
it looks like:

 $ ./perf stat -v -e bus-cycles ls > /dev/null
Error: counter 0, sys_perf_counter_open() syscall returned with -1 (Invalid argument)

 Performance counter stats for 'ls':

  <not counted>  bus-cycles

    0.006765877  seconds time elapsed.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1245757369.3776.1.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 8 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 6d3eeac1ea25..5e04fcc8d077 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -109,6 +109,10 @@ static u64			walltime_nsecs_noise;
 static u64                      runtime_cycles_avg;
 static u64                      runtime_cycles_noise;
 
+
+#define ERR_PERF_OPEN \
+"Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n"
+
 static void create_perf_stat_counter(int counter)
 {
         struct perf_counter_attr *attr = attrs + counter;
@@ -119,20 +123,20 @@ static void create_perf_stat_counter(int counter)
 
         if (system_wide) {
                 int cpu;
-                for (cpu = 0; cpu < nr_cpus; cpu ++) {
+                for (cpu = 0; cpu < nr_cpus; cpu++) {
                         fd[cpu][counter] = sys_perf_counter_open(attr, -1, cpu, -1, 0);
-                        if (fd[cpu][counter] < 0 && verbose) {
-                                printf("Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n", counter, fd[cpu][counter], strerror(errno));
-                        }
+                        if (fd[cpu][counter] < 0 && verbose)
+                                fprintf(stderr, ERR_PERF_OPEN, counter,
+                                        fd[cpu][counter], strerror(errno));
                 }
         } else {
                 attr->inherit   = inherit;
                 attr->disabled  = 1;
 
                 fd[0][counter] = sys_perf_counter_open(attr, 0, -1, -1, 0);
-                if (fd[0][counter] < 0 && verbose) {
-                        printf("Error: counter %d, sys_perf_counter_open() syscall returned with %d (%s)\n", counter, fd[0][counter], strerror(errno));
-                }
+                if (fd[0][counter] < 0 && verbose)
+                        fprintf(stderr, ERR_PERF_OPEN, counter,
+                                fd[0][counter], strerror(errno));
         }
 }
 
@@ -168,7 +172,7 @@ static void read_counter(int counter)
         count[0] = count[1] = count[2] = 0;
 
         nv = scale ? 3 : 1;
-        for (cpu = 0; cpu < nr_cpus; cpu ++) {
+        for (cpu = 0; cpu < nr_cpus; cpu++) {
                 if (fd[cpu][counter] < 0)
                         continue;