tools/perf/stat: Add event unit and scale support

This patch adds perf stat support for handling event units and
scales as exported by the kernel.

The kernel can export PMU events actual unit and scaling factor
via sysfs:

  $ ls -1 /sys/devices/power/events/energy-*
  /sys/devices/power/events/energy-cores
  /sys/devices/power/events/energy-cores.scale
  /sys/devices/power/events/energy-cores.unit
  /sys/devices/power/events/energy-pkg
  /sys/devices/power/events/energy-pkg.scale
  /sys/devices/power/events/energy-pkg.unit
  $ cat /sys/devices/power/events/energy-cores.scale
  2.3283064365386962890625e-10
  $ cat cat /sys/devices/power/events/energy-cores.unit
  Joules

This patch modifies the pmu event alias code to check
for the presence of the .unit and .scale files to load
the corresponding values. They are then used by perf stat
transparently:

   # perf stat -a -e power/energy-pkg/,power/energy-cores/,cycles -I 1000 sleep 1000
   #          time             counts   unit events
       1.000214717               3.07 Joules power/energy-pkg/         [100.00%]
       1.000214717               0.53 Joules power/energy-cores/
       1.000214717           12965028        cycles                    [100.00%]
       2.000749289               3.01 Joules power/energy-pkg/
       2.000749289               0.52 Joules power/energy-cores/
       2.000749289           15817043        cycles

When the event does not have an explicit unit exported by
the kernel, nothing is printed. In csv output mode, there
will be an empty field.

Special thanks to Jiri for providing the supporting code
in the parser to trigger reading of the scale and unit files.

Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: zheng.z.yan@intel.com
Cc: bp@alien8.de
Cc: maria.n.dimakopoulou@gmail.com
Cc: acme@redhat.com
Link: http://lkml.kernel.org/r/1384275531-10892-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 84 insertions, 30 deletions

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index ee0d565f83e3..dab98b50c9fe 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -138,6 +138,7 @@ static const char		*post_cmd			= NULL;
 static bool                     sync_run                        = false;
 static unsigned int             interval                        = 0;
 static unsigned int             initial_delay                   = 0;
+static unsigned int             unit_width                      = 4; /* strlen("unit") */
 static bool                     forever                         = false;
 static struct timespec          ref_time;
 static struct cpu_map           *aggr_map;
@@ -461,17 +462,17 @@ static void print_interval(void)
         if (num_print_interval == 0 && !csv_output) {
                 switch (aggr_mode) {
                 case AGGR_SOCKET:
-                        fprintf(output, "#           time socket cpus             counts events\n");
+                        fprintf(output, "#           time socket cpus             counts %*s events\n", unit_width, "unit");
                         break;
                 case AGGR_CORE:
-                        fprintf(output, "#           time core         cpus             counts events\n");
+                        fprintf(output, "#           time core         cpus             counts %*s events\n", unit_width, "unit");
                         break;
                 case AGGR_NONE:
-                        fprintf(output, "#           time CPU                 counts events\n");
+                        fprintf(output, "#           time CPU                counts %*s events\n", unit_width, "unit");
                         break;
                 case AGGR_GLOBAL:
                 default:
-                        fprintf(output, "#           time             counts events\n");
+                        fprintf(output, "#           time             counts %*s events\n", unit_width, "unit");
                 }
         }
 
@@ -516,6 +517,7 @@ static int __run_perf_stat(int argc, const char **argv)
         unsigned long long t0, t1;
         struct perf_evsel *counter;
         struct timespec ts;
+        size_t l;
         int status = 0;
         const bool forks = (argc > 0);
 
@@ -565,6 +567,10 @@ static int __run_perf_stat(int argc, const char **argv)
                         return -1;
                 }
                 counter->supported = true;
+
+                l = strlen(counter->unit);
+                if (l > unit_width)
+                        unit_width = l;
         }
 
         if (perf_evlist__apply_filters(evsel_list)) {
@@ -704,14 +710,25 @@ static void aggr_printout(struct perf_evsel *evsel, int id, int nr)
 static void nsec_printout(int cpu, int nr, struct perf_evsel *evsel, double avg)
 {
         double msecs = avg / 1e6;
-        const char *fmt = csv_output ? "%.6f%s%s" : "%18.6f%s%-25s";
+        const char *fmt_v, *fmt_n;
         char name[25];
 
+        fmt_v = csv_output ? "%.6f%s" : "%18.6f%s";
+        fmt_n = csv_output ? "%s" : "%-25s";
+
         aggr_printout(evsel, cpu, nr);
 
         scnprintf(name, sizeof(name), "%s%s",
                   perf_evsel__name(evsel), csv_output ? "" : " (msec)");
-        fprintf(output, fmt, msecs, csv_sep, name);
+
+        fprintf(output, fmt_v, msecs, csv_sep);
+
+        if (csv_output)
+                fprintf(output, "%s%s", evsel->unit, csv_sep);
+        else
+                fprintf(output, "%-*s%s", unit_width, evsel->unit, csv_sep);
+
+        fprintf(output, fmt_n, name);
 
         if (evsel->cgrp)
                 fprintf(output, "%s%s", csv_sep, evsel->cgrp->name);
@@ -908,21 +925,31 @@ static void print_ll_cache_misses(int cpu,
 static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg)
 {
         double total, ratio = 0.0, total2;
+        double sc =  evsel->scale;
         const char *fmt;
 
-        if (csv_output)
-                fmt = "%.0f%s%s";
-        else if (big_num)
-                fmt = "%'18.0f%s%-25s";
-        else
-                fmt = "%18.0f%s%-25s";
+        if (csv_output) {
+                fmt = sc != 1.0 ?  "%.2f%s" : "%.0f%s";
+        } else {
+                if (big_num)
+                        fmt = sc != 1.0 ? "%'18.2f%s" : "%'18.0f%s";
+                else
+                        fmt = sc != 1.0 ? "%18.2f%s" : "%18.0f%s";
+        }
 
         aggr_printout(evsel, cpu, nr);
 
         if (aggr_mode == AGGR_GLOBAL)
                 cpu = 0;
 
-        fprintf(output, fmt, avg, csv_sep, perf_evsel__name(evsel));
+        fprintf(output, fmt, avg, csv_sep);
+
+        if (evsel->unit)
+                fprintf(output, "%-*s%s",
+                        csv_output ? 0 : unit_width,
+                        evsel->unit, csv_sep);
+
+        fprintf(output, "%-*s", csv_output ? 0 : 25, perf_evsel__name(evsel));
 
         if (evsel->cgrp)
                 fprintf(output, "%s%s", csv_sep, evsel->cgrp->name);
@@ -941,7 +968,10 @@ static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg)
 
                 if (total && avg) {
                         ratio = total / avg;
-                        fprintf(output, "\n                                             #   %5.2f  stalled cycles per insn", ratio);
+                        fprintf(output, "\n");
+                        if (aggr_mode == AGGR_NONE)
+                                fprintf(output, "        ");
+                        fprintf(output, "                                                  #   %5.2f  stalled cycles per insn", ratio);
                 }
 
         } else if (perf_evsel__match(evsel, HARDWARE, HW_BRANCH_MISSES) &&
@@ -1061,6 +1091,7 @@ static void print_aggr(char *prefix)
 {
         struct perf_evsel *counter;
         int cpu, cpu2, s, s2, id, nr;
+        double uval;
         u64 ena, run, val;
 
         if (!(aggr_map || aggr_get_id))
@@ -1087,11 +1118,17 @@ static void print_aggr(char *prefix)
                         if (run == 0 || ena == 0) {
                                 aggr_printout(counter, id, nr);
 
-                                fprintf(output, "%*s%s%*s",
+                                fprintf(output, "%*s%s",
                                         csv_output ? 0 : 18,
                                         counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
-                                        csv_sep,
-                                        csv_output ? 0 : -24,
+                                        csv_sep);
+
+                                fprintf(output, "%-*s%s",
+                                        csv_output ? 0 : unit_width,
+                                        counter->unit, csv_sep);
+
+                                fprintf(output, "%*s",
+                                        csv_output ? 0 : -25,
                                         perf_evsel__name(counter));
 
                                 if (counter->cgrp)
@@ -1101,11 +1138,12 @@ static void print_aggr(char *prefix)
                                 fputc('\n', output);
                                 continue;
                         }
+                        uval = val * counter->scale;
 
                         if (nsec_counter(counter))
-                                nsec_printout(id, nr, counter, val);
+                                nsec_printout(id, nr, counter, uval);
                         else
-                                abs_printout(id, nr, counter, val);
+                                abs_printout(id, nr, counter, uval);
 
                         if (!csv_output) {
                                 print_noise(counter, 1.0);
@@ -1128,16 +1166,21 @@ static void print_counter_aggr(struct perf_evsel *counter, char *prefix)
         struct perf_stat *ps = counter->priv;
         double avg = avg_stats(&ps->res_stats[0]);
         int scaled = counter->counts->scaled;
+        double uval;
 
         if (prefix)
                 fprintf(output, "%s", prefix);
 
         if (scaled == -1) {
-                fprintf(output, "%*s%s%*s",
+                fprintf(output, "%*s%s",
                         csv_output ? 0 : 18,
                         counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
-                        csv_sep,
-                        csv_output ? 0 : -24,
+                        csv_sep);
+                fprintf(output, "%-*s%s",
+                        csv_output ? 0 : unit_width,
+                        counter->unit, csv_sep);
+                fprintf(output, "%*s",
+                        csv_output ? 0 : -25,
                         perf_evsel__name(counter));
 
                 if (counter->cgrp)
@@ -1147,10 +1190,12 @@ static void print_counter_aggr(struct perf_evsel *counter, char *prefix)
                 return;
         }
 
+        uval = avg * counter->scale;
+
         if (nsec_counter(counter))
-                nsec_printout(-1, 0, counter, avg);
+                nsec_printout(-1, 0, counter, uval);
         else
-                abs_printout(-1, 0, counter, avg);
+                abs_printout(-1, 0, counter, uval);
 
         print_noise(counter, avg);
 
@@ -1177,6 +1222,7 @@ static void print_counter_aggr(struct perf_evsel *counter, char *prefix)
 static void print_counter(struct perf_evsel *counter, char *prefix)
 {
         u64 ena, run, val;
+        double uval;
         int cpu;
 
         for (cpu = 0; cpu < perf_evsel__nr_cpus(counter); cpu++) {
@@ -1188,14 +1234,20 @@ static void print_counter(struct perf_evsel *counter, char *prefix)
                         fprintf(output, "%s", prefix);
 
                 if (run == 0 || ena == 0) {
-                        fprintf(output, "CPU%*d%s%*s%s%*s",
+                        fprintf(output, "CPU%*d%s%*s%s",
                                 csv_output ? 0 : -4,
                                 perf_evsel__cpus(counter)->map[cpu], csv_sep,
                                 csv_output ? 0 : 18,
                                 counter->supported ? CNTR_NOT_COUNTED : CNTR_NOT_SUPPORTED,
-                                csv_sep,
-                                csv_output ? 0 : -24,
-                                perf_evsel__name(counter));
+                                csv_sep);
+
+                                fprintf(output, "%-*s%s",
+                                        csv_output ? 0 : unit_width,
+                                        counter->unit, csv_sep);
+
+                                fprintf(output, "%*s",
+                                        csv_output ? 0 : -25,
+                                        perf_evsel__name(counter));
 
                         if (counter->cgrp)
                                 fprintf(output, "%s%s",
@@ -1205,10 +1257,12 @@ static void print_counter(struct perf_evsel *counter, char *prefix)
                         continue;
                 }
 
+                uval = val * counter->scale;
+
                 if (nsec_counter(counter))
-                        nsec_printout(cpu, 0, counter, val);
+                        nsec_printout(cpu, 0, counter, uval);
                 else
-                        abs_printout(cpu, 0, counter, val);
+                        abs_printout(cpu, 0, counter, uval);
 
                 if (!csv_output) {
                         print_noise(counter, 1.0);