Commit 75998bb2 authored by Andi Kleen's avatar Andi Kleen Committed by Arnaldo Carvalho de Melo
Browse files

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: default avatarAndi Kleen <ak@linux.intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 90b10f47

tools/perf/Documentation/perf-stat.txt

+2 −3
Original line number Diff line number Diff line
@@ -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::

tools/perf/builtin-stat.c

+2 −1
Original line number Diff line number Diff line
@@ -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,

tools/perf/util/evsel.c

+1 −2
Original line number Diff line number Diff line
@@ -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;

tools/perf/util/stat.c

+4 −8
Original line number Diff line number Diff line
@@ -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;

		}

	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;

	}



	/*

	 * The event is part of non trivial group, let's enable

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