linux-kernel - [RFC/PATCH 3/4] perf tools: Change default calchain percent limit to 0.05%

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Date:	Wed,  3 Feb 2016 23:11:22 +0900
From:	Namhyung Kim <namhyung@...nel.org>
To:	Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Jiri Olsa <jolsa@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	David Ahern <dsahern@...il.com>,
	Andi Kleen <andi@...stfloor.org>,
	Stephane Eranian <eranian@...gle.com>,
	Wang Nan <wangnan0@...wei.com>
Subject: [RFC/PATCH 3/4] perf tools: Change default calchain percent limit to 0.05%

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: Andi Kleen <andi@...stfloor.org>
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
changed from 0.005 -> 0.05

 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 369663b37361..7c7b6b6129f7 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 0.05 (%).
 
 	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..d7ad5333d50f 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,0.05,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..f31cb78c92fb 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,0.05,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 b9e2843cfbe7..26b8f6c66d00 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 = 0.05,
 	.order  = ORDER_CALLEE,
 	.key	= CCKEY_FUNCTION,
 	.value	= CCVAL_PERCENT,
-- 
2.7.0