[RFC/PATCH 10/10] perf tools: Change default calchain percent limit to 0.005%

From: Namhyung Kim
Date: Wed Jan 27 2016 - 10:44:14 EST


The current default limit of 0.5% is (mostly) for 'fractal' mode which
calculates the percentage relatively. As we changed the default
callchain mode to 'graph', the existing limit is too high IMHO.
Normally there're many entries under 0.5% overhead, it'd be supprising
that they don't show callchains.

Cc: Taeung Song <treeze.taeung@xxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/Documentation/perf-report.txt | 2 +-
tools/perf/builtin-report.c | 2 +-
tools/perf/builtin-top.c | 2 +-
tools/perf/util/util.c | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index 8a301f6afb37..1591b45c79e5 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -209,7 +209,7 @@ OPTIONS
- none: disable call chain display.

threshold is a percentage value which specifies a minimum percent to be
- included in the output call graph. Default is 0.5 (%).
+ included in the output call graph. Default is 0.005 (%).

print_limit is only applied when stdio interface is used. It's to limit
number of call graph entries in a single hist entry. Note that it needs
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index 72ed0b46d5a1..ba6eba5f5d69 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -643,7 +643,7 @@ parse_percent_limit(const struct option *opt, const char *str,
return 0;
}

-#define CALLCHAIN_DEFAULT_OPT "graph,0.5,caller,function,percent"
+#define CALLCHAIN_DEFAULT_OPT "graph,0.005,caller,function,percent"

const char report_callchain_help[] = "Display call graph (stack chain/backtrace):\n\n"
CALLCHAIN_REPORT_HELP
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index bf01cbb0ef23..1b471135ae2d 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1086,7 +1086,7 @@ parse_percent_limit(const struct option *opt, const char *arg,
}

const char top_callchain_help[] = CALLCHAIN_RECORD_HELP CALLCHAIN_REPORT_HELP
- "\n\t\t\t\tDefault: fp,graph,0.5,caller,function";
+ "\n\t\t\t\tDefault: fp,graph,0.005,caller,function";

int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
{
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 7a2da7ef556e..25ae6989c89d 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -20,7 +20,7 @@

struct callchain_param callchain_param = {
.mode = CHAIN_GRAPH_ABS,
- .min_percent = 0.5,
+ .min_percent = 0.005,
.order = ORDER_CALLEE,
.key = CCKEY_FUNCTION,
.value = CCVAL_PERCENT,
--
2.6.4