perf stat: Support duration_time for metrics

Some of the metrics formulas (like GFLOPs) need to know how long the
measurement period is. Support an internal event called duration_time,
which reports time in second. It maps to the dummy event, but is special
cased for statistics to report the walltime duration.

So far it is not printed, but only used internally for metrics.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20170831194036.30146-10-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/parse-events.l b/tools/perf/util/parse-events.l
index fdb5bb52f01fa4e340de7d56167d27b8138e5a71..ea2426daf7e824e62c4ad7785451eedb4950c8a8 100644 (file)
--- a/tools/perf/util/parse-events.l
+++ b/tools/perf/util/parse-events.l
@@ -288,6 +288,7 @@ cpu-migrations|migrations                   { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COU
 alignment-faults                               { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_ALIGNMENT_FAULTS); }
 emulation-faults                               { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_EMULATION_FAULTS); }
 dummy                                          { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_DUMMY); }
+duration_time                                  { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_DUMMY); }
 bpf-output                                     { return sym(yyscanner, PERF_TYPE_SOFTWARE, PERF_COUNT_SW_BPF_OUTPUT); }
 
        /*

diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 664f49a9b0123705e9b006d2a45e43d9a80f9b42..a2c12d1ef32a3266360b000ca06b3817a7669a85 100644 (file)
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -641,11 +641,20 @@ static void generic_metric(const char *metric_expr,
        expr__add_id(&pctx, name, avg);
        for (i = 0; metric_events[i]; i++) {
                struct saved_value *v;
+               struct stats *stats;
+               double scale;
 
-               v = saved_value_lookup(metric_events[i], cpu, false);
-               if (!v)
-                       break;
-               expr__add_id(&pctx, metric_events[i]->name, avg_stats(&v->stats));
+               if (!strcmp(metric_events[i]->name, "duration_time")) {
+                       stats = &walltime_nsecs_stats;
+                       scale = 1e-9;
+               } else {
+                       v = saved_value_lookup(metric_events[i], cpu, false);
+                       if (!v)
+                               break;
+                       stats = &v->stats;
+                       scale = 1.0;
+               }
+               expr__add_id(&pctx, metric_events[i]->name, avg_stats(stats)*scale);
        }
        if (!metric_events[i]) {
                const char *p = metric_expr;