[PATCH v2 2/4] perf config: Finally write changed configs on config file at a time

[Taeung Song <treeze.taeung@gmail.com>]

Currently set_config() can be repeatedly called for each
input config on the below case:

  $ perf config kmem.default=slab report.children=false ...

But it's a waste, so finally write changed configs at a time.

Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
 tools/perf/builtin-config.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 7545966..0d38599 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -33,8 +33,7 @@ static struct option config_options[] = {
 	OPT_END()
 };
 
-static int set_config(struct perf_config_set *set, const char *file_name,
-		      const char *var, const char *value)
+static int set_config(struct perf_config_set *set, const char *file_name)
 {
 	struct perf_config_section *section = NULL;
 	struct perf_config_item *item = NULL;
@@ -48,7 +47,6 @@ static int set_config(struct perf_config_set *set, const char *file_name,
 	if (!fp)
 		return -1;
 
-	perf_config_set__collect(set, file_name, var, value);
 	fprintf(fp, "%s\n", first_line);
 
 	/* overwrite configvariables */
@@ -160,6 +158,7 @@ int cmd_config(int argc, const char **argv)
 	struct perf_config_set *set;
 	char *user_config = mkpath("%s/.perfconfig", getenv("HOME"));
 	const char *config_filename;
+	bool changed = false;
 
 	argc = parse_options(argc, argv, config_options, config_usage,
 			     PARSE_OPT_STOP_AT_NON_OPTION);
@@ -227,10 +226,16 @@ int cmd_config(int argc, const char **argv)
 
 			if (value == NULL)
 				ret = show_spec_config(set, var);
-			else
-				ret = set_config(set, config_filename, var, value);
+			else {
+				perf_config_set__collect(set, config_filename,
+							 var, value);
+				changed = true;
+			}
 			free(arg);
 		}
+
+		if (changed)
+			ret = set_config(set, config_filename);
 	}
 
 	perf_config_set__delete(set);
-- 
2.7.4