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>

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 6d3eeac1ea257b47c898dae49c6336c35c4c43f4..5e04fcc8d07763d352d920873cda095d37d07149 100644 (file)
--- 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;