[PATCH] perf stat: Align CSV output for summary mode

[Jin Yao]

perf-stat has supported the summary mode. But the summary
lines break the CSV output so it's hard for scripts to parse
the result.

Before:

  # perf stat -x, -I1000 --interval-count 1 --summary
       1.001323097,8013.48,msec,cpu-clock,8013483384,100.00,8.013,CPUs utilized
       1.001323097,270,,context-switches,8013513297,100.00,0.034,K/sec
       1.001323097,13,,cpu-migrations,8013530032,100.00,0.002,K/sec
       1.001323097,184,,page-faults,8013546992,100.00,0.023,K/sec
       1.001323097,20574191,,cycles,8013551506,100.00,0.003,GHz
       1.001323097,10562267,,instructions,8013564958,100.00,0.51,insn per cycle
       1.001323097,2019244,,branches,8013575673,100.00,0.252,M/sec
       1.001323097,106152,,branch-misses,8013585776,100.00,5.26,of all branches
  8013.48,msec,cpu-clock,8013483384,100.00,7.984,CPUs utilized
  270,,context-switches,8013513297,100.00,0.034,K/sec
  13,,cpu-migrations,8013530032,100.00,0.002,K/sec
  184,,page-faults,8013546992,100.00,0.023,K/sec
  20574191,,cycles,8013551506,100.00,0.003,GHz
  10562267,,instructions,8013564958,100.00,0.51,insn per cycle
  2019244,,branches,8013575673,100.00,0.252,M/sec
  106152,,branch-misses,8013585776,100.00,5.26,of all branches

The summary line loses the timestamp column, which breaks the
CVS output.

We add a column at the 'timestamp' position and it just says 'summary'
for the summary line.

After:

  # perf stat -x, -I1000 --interval-count 1 --summary
       1.001196053,8012.72,msec,cpu-clock,8012722903,100.00,8.013,CPUs utilized
       1.001196053,218,,context-switches,8012753271,100.00,0.027,K/sec
       1.001196053,9,,cpu-migrations,8012769767,100.00,0.001,K/sec
       1.001196053,0,,page-faults,8012786257,100.00,0.000,K/sec
       1.001196053,15004518,,cycles,8012790637,100.00,0.002,GHz
       1.001196053,7954691,,instructions,8012804027,100.00,0.53,insn per cycle
       1.001196053,1590259,,branches,8012814766,100.00,0.198,M/sec
       1.001196053,82601,,branch-misses,8012824365,100.00,5.19,of all branches
           summary,8012.72,msec,cpu-clock,8012722903,100.00,7.986,CPUs utilized
           summary,218,,context-switches,8012753271,100.00,0.027,K/sec
           summary,9,,cpu-migrations,8012769767,100.00,0.001,K/sec
           summary,0,,page-faults,8012786257,100.00,0.000,K/sec
           summary,15004518,,cycles,8012790637,100.00,0.002,GHz
           summary,7954691,,instructions,8012804027,100.00,0.53,insn per cycle
           summary,1590259,,branches,8012814766,100.00,0.198,M/sec
           summary,82601,,branch-misses,8012824365,100.00,5.19,of all branches

Now it's easy for script to analyse the summary lines.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
 tools/perf/util/stat-display.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
index 7f09cdaf5b60..c4183d3e87a4 100644
--- a/tools/perf/util/stat-display.c
+++ b/tools/perf/util/stat-display.c
@@ -439,6 +439,10 @@ static void printout(struct perf_stat_config *config, struct aggr_cpu_id id, int
 		if (counter->cgrp)
 			os.nfields++;
 	}
+
+	if (config->csv_output && config->summary && !config->interval)
+		fprintf(config->output, "%16s%s", "summary", config->csv_sep);
+
 	if (run == 0 || ena == 0 || counter->counts->scaled == -1) {
 		if (config->metric_only) {
 			pm(config, &os, NULL, "", "", 0);
-- 
2.17.1