[tip:perf/core] perf stat: Display length strings of each run for --table option

From: tip-bot for Jiri Olsa
Date: Wed May 02 2018 - 13:43:09 EST


Commit-ID: abc60bad0030193ffb55e438664bc09ac53939cf
Gitweb: https://git.kernel.org/tip/abc60bad0030193ffb55e438664bc09ac53939cf
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Mon, 23 Apr 2018 11:08:22 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 26 Apr 2018 09:30:27 -0300

perf stat: Display length strings of each run for --table option

Adding support to display visual aid 'length strings' to easily spot the
biggest difference in time table.

$ perf stat -r 10 --table perf bench sched pipe
...

Performance counter stats for './perf bench sched pipe' (5 runs):

# Table of individual measurements:
5.189 (-0.293) #
5.189 (-0.294) #
5.186 (-0.296) #
5.663 (+0.181) ##
6.186 (+0.703) ####

# Final result:
5.483 +- 0.198 seconds time elapsed ( +- 3.62% )

Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Tested-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180423090823.32309-9-jolsa@xxxxxxxxxx
[ Updated 'perf stat --table' man page entry ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/Documentation/perf-stat.txt | 12 ++++++------
tools/perf/builtin-stat.c | 8 +++++++-
2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 72a2414513bd..3a822f308e6d 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -123,14 +123,14 @@ spreadsheets. Columns are separated by the string specified in SEP.
Performance counter stats for 'perf bench sched pipe' (5 runs):

# Table of individual measurements:
- 5.379 (-0.176)
- 5.243 (-0.311)
- 5.238 (-0.317)
- 5.536 (-0.019)
- 6.377 (+0.823)
+ 5.189 (-0.293) #
+ 5.189 (-0.294) #
+ 5.186 (-0.296) #
+ 5.663 (+0.181) ##
+ 6.186 (+0.703) ####

# Final result:
- 5.555 +- 0.213 seconds time elapsed ( +- 3.83% )
+ 5.483 +- 0.198 seconds time elapsed ( +- 3.62% )

-G name::
--cgroup name::
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 72553937c010..a4f662a462c6 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -1790,9 +1790,15 @@ static void print_table(FILE *output, int precision, double avg)

for (idx = 0; idx < run_count; idx++) {
double run = (double) walltime_run[idx] / NSEC_PER_SEC;
+ int h, n = 1 + abs((int) (100.0 * (run - avg)/run) / 5);

- fprintf(output, " %17.*f (%+.*f)\n",
+ fprintf(output, " %17.*f (%+.*f) ",
precision, run, precision, run - avg);
+
+ for (h = 0; h < n; h++)
+ fprintf(output, "#");
+
+ fprintf(output, "\n");
}

fprintf(output, "\n%*s# Final result:\n", indent, "");