perf config: Document 'hist.percentage' variable in man page

Explain 'hist.percentage' variable.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1452253193-30502-7-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-config.txt b/tools/perf/Documentation/perf-config.txt
index cb7ca507ec5e..74589c68558a 100644
--- a/tools/perf/Documentation/perf-config.txt
+++ b/tools/perf/Documentation/perf-config.txt
@@ -279,6 +279,23 @@ annotate.*::
 
                 99.93 │      mov    %eax,%eax
 
+hist.*::
+        hist.percentage::
+                This option control the way to calculate overhead of filtered entries -
+                that means the value of this option is effective only if there's a
+                filter (by comm, dso or symbol name). Suppose a following example:
+
+                       Overhead  Symbols
+                       ........  .......
+                        33.33%     foo
+                        33.33%     bar
+                        33.33%     baz
+
+               This is an original overhead and we'll filter out the first 'foo'
+               entry. The value of 'relative' would increase the overhead of 'bar'
+               and 'baz' to 50.00% for each, while 'absolute' would show their
+               current overhead (33.33%).
+
 SEE ALSO
 --------
 linkperf:perf[1]