[RFC][PATCH v2 0/5] perf config: Reimplement perf_config() using perf_config_set__inter()

[RFC][PATCH v2 0/5] perf config: Reimplement perf_config() using perf_config_set__inter()

[Taeung Song]

Everytime perf_config() is called, perf_config() always read config files.
(i.e. user config '~/.perfconfig' and system config '$(sysconfdir)/perfconfig')

But we need to use 'struct perf_config_set config_set' variable
that already contains all config key-value pairs
to avoid this repetitive work in perf_config().

In other words, if new perf_config() is called,
only first time 'config_set' is initialized
collecting all configs from config files and it work with perf_config_set__iter().

If we do, what old perf_config() handle is the same as new perf_config() work
without the repetitive work that read config files.

IMHO, I think this patchset is needed because not only the repetitive work
should be avoided but also in near future, it would be smooth to manage perf configs.

If you give me any feedback, I'd apprecicated it. :)

Thanks,
Taeung

v2:
- split a patch into several patches
- reimplement show_config() using new perf_config()
- modify perf_config_set__delete using global variable 'config_set'
- reset config set when only 'config' sub-commaned work
  because of options for config file location

Taeung Song (5):
  perf config: Use new perf_config_set__init() to initialize config set
  perf config: Reimplement perf_config() using perf_config_set__iter()
  perf config: Modify perf_config_set__delete() using global variable
    'config_set'
  perf config: Reimplement show_config() using perf_config()
  perf config: Reset config set at only 'config' sub-command

 tools/perf/builtin-config.c |  43 ++++--------
 tools/perf/util/config.c    | 156 +++++++++++++++++++++++++++++---------------
 tools/perf/util/config.h    |   2 +-
 3 files changed, 117 insertions(+), 84 deletions(-)

-- 
2.5.0

[PATCH v2 1/5] perf config: Use new perf_config_set__init() to initialize config set

[Taeung Song]

Instead of perf_config(), This function initialize config set
collecting all configs from config files (i.e. user config
~/.perfconfig and system config $(sysconfdir)/perfconfig).

If there are the same config variable both user and system
config file, user config has higher priority than system config.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
 tools/perf/util/config.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index dad7d82..5d01899 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -645,13 +645,61 @@ out_free:
 	return -1;
 }
 
+static int perf_config_set__init(struct perf_config_set *set)
+{
+	int ret = 0, found = 0;
+	const char *home = NULL;
+
+	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
+	if (config_exclusive_filename)
+		return perf_config_from_file(collect_config, config_exclusive_filename, set);
+	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
+		ret += perf_config_from_file(collect_config, perf_etc_perfconfig(), set);
+		found += 1;
+	}
+
+	home = getenv("HOME");
+	if (perf_config_global() && home) {
+		char *user_config = strdup(mkpath("%s/.perfconfig", home));
+		struct stat st;
+
+		if (user_config == NULL) {
+			warning("Not enough memory to process %s/.perfconfig, "
+				"ignoring it.", home);
+			goto out;
+		}
+
+		if (stat(user_config, &st) < 0)
+			goto out_free;
+
+		if (st.st_uid && (st.st_uid != geteuid())) {
+			warning("File %s not owned by current user or root, "
+				"ignoring it.", user_config);
+			goto out_free;
+		}
+
+		if (!st.st_size)
+			goto out_free;
+
+		ret += perf_config_from_file(collect_config, user_config, set);
+		found += 1;
+out_free:
+		free(user_config);
+	}
+out:
+	if (found == 0)
+		return -1;
+	return ret;
+}
+
 struct perf_config_set *perf_config_set__new(void)
 {
 	struct perf_config_set *set = zalloc(sizeof(*set));
 
 	if (set) {
 		INIT_LIST_HEAD(&set->sections);
-		perf_config(collect_config, set);
+		if (perf_config_set__init(set) < 0)
+			return NULL;
 	}
 
 	return set;
-- 
2.5.0

[PATCH v2 2/5] perf config: Reimplement perf_config() using perf_config_set__iter()

[Taeung Song]

Everytime perf_config() is called, perf_config() always read config files.
(i.e. user config '~/.perfconfig' and system config '$(sysconfdir)/perfconfig')

But we need to use config set that already contains all config
key-value pairs to avoid this repetitive work reading the config files
in perf_config().

In other words, if new perf_config() is called,
only first time 'config_set' is initialized collecting all configs
from the config files and it work with perf_config_set__iter().

If we do, what old perf_config() handle is the same as new perf_config() work
without the repetitive work that read the config files.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
 tools/perf/util/config.c | 98 ++++++++++++++++++++++++------------------------
 1 file changed, 50 insertions(+), 48 deletions(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 5d01899..487d390 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -28,6 +28,7 @@ static int config_linenr;
 static int config_file_eof;
 
 const char *config_exclusive_filename;
+struct perf_config_set *config_set;
 
 static int get_next_char(void)
 {
@@ -477,54 +478,6 @@ static int perf_config_global(void)
 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 }
 
-int perf_config(config_fn_t fn, void *data)
-{
-	int ret = 0, found = 0;
-	const char *home = NULL;
-
-	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
-	if (config_exclusive_filename)
-		return perf_config_from_file(fn, config_exclusive_filename, data);
-	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
-		ret += perf_config_from_file(fn, perf_etc_perfconfig(),
-					    data);
-		found += 1;
-	}
-
-	home = getenv("HOME");
-	if (perf_config_global() && home) {
-		char *user_config = strdup(mkpath("%s/.perfconfig", home));
-		struct stat st;
-
-		if (user_config == NULL) {
-			warning("Not enough memory to process %s/.perfconfig, "
-				"ignoring it.", home);
-			goto out;
-		}
-
-		if (stat(user_config, &st) < 0)
-			goto out_free;
-
-		if (st.st_uid && (st.st_uid != geteuid())) {
-			warning("File %s not owned by current user or root, "
-				"ignoring it.", user_config);
-			goto out_free;
-		}
-
-		if (!st.st_size)
-			goto out_free;
-
-		ret += perf_config_from_file(fn, user_config, data);
-		found += 1;
-out_free:
-		free(user_config);
-	}
-out:
-	if (found == 0)
-		return -1;
-	return ret;
-}
-
 static struct perf_config_section *find_section(struct list_head *sections,
 						const char *section_name)
 {
@@ -705,6 +658,55 @@ struct perf_config_set *perf_config_set__new(void)
 	return set;
 }
 
+static int perf_config_set__check(void)
+{
+	if (config_set != NULL)
+		return 0;
+
+	config_set = perf_config_set__new();
+	if (!config_set)
+		return -1;
+
+	return 0;
+}
+
+static int perf_config_set__iter(struct perf_config_set *set, config_fn_t fn, void *data)
+{
+	struct perf_config_section *section;
+	struct perf_config_item *item;
+	struct list_head *sections;
+	char key[BUFSIZ];
+
+	if (set == NULL)
+		return -1;
+
+	sections = &set->sections;
+	if (list_empty(sections))
+		return -1;
+
+	list_for_each_entry(section, sections, node) {
+		list_for_each_entry(item, &section->items, node) {
+			char *value = item->value;
+
+			if (value) {
+				scnprintf(key, sizeof(key), "%s.%s",
+					  section->name, item->name);
+				if (fn(key, value, data) < 0)
+					return -1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+int perf_config(config_fn_t fn, void *data)
+{
+	if (perf_config_set__check() < 0)
+		return -1;
+	return perf_config_set__iter(config_set, fn, data);
+}
+
 static void perf_config_item__delete(struct perf_config_item *item)
 {
 	zfree(&item->name);
-- 
2.5.0

[PATCH v2 3/5] perf config: Modify perf_config_set__delete() using global variable 'config_set'

[Taeung Song]

This function deleted allocated config set but
the global variable 'config_set' is used all around
so this directly remove 'config_set' instead of using local variable 'set'.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
 tools/perf/builtin-config.c | 2 +-
 tools/perf/util/config.c    | 8 ++++----
 tools/perf/util/config.h    | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index fe1b77f..8eef3fb 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -106,7 +106,7 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 		usage_with_options(config_usage, config_options);
 	}
 
-	perf_config_set__delete(set);
+	perf_config_set__delete();
 out_err:
 	return ret;
 }
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 487d390..abfe1b2 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -594,7 +594,7 @@ static int collect_config(const char *var, const char *value,
 
 out_free:
 	free(key);
-	perf_config_set__delete(set);
+	perf_config_set__delete();
 	return -1;
 }
 
@@ -741,10 +741,10 @@ static void perf_config_set__purge(struct perf_config_set *set)
 	}
 }
 
-void perf_config_set__delete(struct perf_config_set *set)
+void perf_config_set__delete(void)
 {
-	perf_config_set__purge(set);
-	free(set);
+	perf_config_set__purge(config_set);
+	zfree(&config_set);
 }
 
 /*
diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
index 22ec626..be4e603 100644
--- a/tools/perf/util/config.h
+++ b/tools/perf/util/config.h
@@ -21,6 +21,6 @@ struct perf_config_set {
 };
 
 struct perf_config_set *perf_config_set__new(void);
-void perf_config_set__delete(struct perf_config_set *set);
+void perf_config_set__delete(void);
 
 #endif /* __PERF_CONFIG_H */
-- 
2.5.0

[PATCH v2 4/5] perf config: Reimplement show_config() using perf_config()

[Taeung Song]

Old show_config() directly use config set so
there are many duplicated code with perf_config_set__iter().

So reimplement show_config() using perf_config() that use
perf_config_set__iter() with config set that already
contains all configs.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
 tools/perf/builtin-config.c | 29 +++++++----------------------
 1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 8eef3fb..4a61411 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -33,28 +33,13 @@ static struct option config_options[] = {
 	OPT_END()
 };
 
-static int show_config(struct perf_config_set *set)
+static int show_config(const char *key, const char *value,
+		       void *cb __maybe_unused)
 {
-	struct perf_config_section *section;
-	struct perf_config_item *item;
-	struct list_head *sections;
-
-	if (set == NULL)
-		return -1;
-
-	sections = &set->sections;
-	if (list_empty(sections))
-		return -1;
-
-	list_for_each_entry(section, sections, node) {
-		list_for_each_entry(item, &section->items, node) {
-			char *value = item->value;
-
-			if (value)
-				printf("%s.%s=%s\n", section->name,
-				       item->name, value);
-		}
-	}
+	if (value)
+		printf("%s=%s\n", key, value);
+	else
+		printf("%s\n", key);
 
 	return 0;
 }
@@ -92,7 +77,7 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 			pr_err("Error: takes no arguments\n");
 			parse_options_usage(config_usage, config_options, "l", 1);
 		} else {
-			ret = show_config(set);
+			ret = perf_config(show_config, NULL);
 			if (ret < 0) {
 				const char * config_filename = config_exclusive_filename;
 				if (!config_exclusive_filename)
-- 
2.5.0

[PATCH v2 5/5] perf config: Reset config set at only 'config' sub-command

[Taeung Song]

When first calling perf_config(), config set is
initialized but 'config' sub-command need to reset
config set because of '--user' or '--system' options.

The options of 'config' sub-command is to select
a particular config file location so the config set
should be reinitialized collecting configs from
selected exclusive config file.

Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
---
 tools/perf/builtin-config.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 4a61411..dc5b52f 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -47,7 +47,6 @@ static int show_config(const char *key, const char *value,
 int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	int ret = 0;
-	struct perf_config_set *set;
 	char *user_config = mkpath("%s/.perfconfig", getenv("HOME"));
 
 	argc = parse_options(argc, argv, config_options, config_usage,
@@ -65,11 +64,11 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 	else if (use_user_config)
 		config_exclusive_filename = user_config;
 
-	set = perf_config_set__new();
-	if (!set) {
-		ret = -1;
-		goto out_err;
-	}
+	/*
+	 * Reset config set at only 'config' sub-command
+	 * because of options config file location.
+	 */
+	perf_config_set__delete();
 
 	switch (actions) {
 	case ACTION_LIST:
@@ -92,6 +91,5 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 	}
 
 	perf_config_set__delete();
-out_err:
 	return ret;
 }
-- 
2.5.0