perf stat: Fix --no-scale

The -c option to enable multiplex scaling has been useless for quite
some time because scaling is default.

It's only useful as --no-scale to disable scaling. But the non scaling
code path has bitrotted and doesn't print anything because perf output
code relies on value run/ena information.

Also even when we don't want to scale a value it's still useful to show
its multiplex percentage.

This patch:
  - Fixes help and documentation to show --no-scale instead of -c
  - Removes -c, only keeps the long option because -c doesn't support negatives.
  - Enables running/enabled even with --no-scale
  - And fixes some other problems in the no-scale output.

Before:

  $ perf stat --no-scale -e cycles true

   Performance counter stats for 'true':

       <not counted>      cycles

         0.000984154 seconds time elapsed

After:

  $ ./perf stat --no-scale -e cycles true

   Performance counter stats for 'true':

             706,070      cycles

         0.001219821 seconds time elapsed

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
LPU-Reference: 20190314225002.30108-9-andi@firstfloor.org
Link: https://lkml.kernel.org/n/tip-xggjvwcdaj2aqy8ib3i4b1g6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 4bc2085..39c05f8 100644 (file)
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -72,9 +72,8 @@ report::
 --all-cpus::
         system-wide collection from all CPUs (default if no target is specified)
 
--c::
---scale::
-       scale/normalize counter values
+--no-scale::
+       Don't scale/normalize counter values
 
 -d::
 --detailed::

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 7b8f09b..49ee3c2 100644 (file)
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -718,7 +718,8 @@ static struct option stat_options[] = {
                    "system-wide collection from all CPUs"),
        OPT_BOOLEAN('g', "group", &group,
                    "put the counters into a counter group"),
-       OPT_BOOLEAN('c', "scale", &stat_config.scale, "scale/normalize counters"),
+       OPT_BOOLEAN(0, "scale", &stat_config.scale,
+                   "Use --no-scale to disable counter scaling for multiplexing"),
        OPT_INCR('v', "verbose", &verbose,
                    "be more verbose (show counter open errors, etc)"),
        OPT_INTEGER('r', "repeat", &stat_config.run_count,

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3bbf73e..53ec40c 100644 (file)
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1344,8 +1344,7 @@ void perf_counts_values__scale(struct perf_counts_values *count,
                        scaled = 1;
                        count->val = (u64)((double) count->val * count->ena / count->run + 0.5);
                }
-       } else
-               count->ena = count->run = 0;
+       }
 
        if (pscaled)
                *pscaled = scaled;

diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 4d40515..2856cc9 100644 (file)
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -291,10 +291,8 @@ process_counter_values(struct perf_stat_config *config, struct perf_evsel *evsel
                break;
        case AGGR_GLOBAL:
                aggr->val += count->val;
-               if (config->scale) {
-                       aggr->ena += count->ena;
-                       aggr->run += count->run;
-               }
+               aggr->ena += count->ena;
+               aggr->run += count->run;
        case AGGR_UNSET:
        default:
                break;
@@ -442,10 +440,8 @@ int create_perf_stat_counter(struct perf_evsel *evsel,
        struct perf_event_attr *attr = &evsel->attr;
        struct perf_evsel *leader = evsel->leader;
 
-       if (config->scale) {
-               attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
-                                   PERF_FORMAT_TOTAL_TIME_RUNNING;
-       }
+       attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
+                           PERF_FORMAT_TOTAL_TIME_RUNNING;
 
        /*
         * The event is part of non trivial group, let's enable