[RFC][PATCH v7 0/9] perf config: Reimplement perf_config() using perf_config_set__inter()

[RFC][PATCH v7 0/9] perf config: Reimplement perf_config() using perf_config_set__inter()

[Taeung Song]

Hello, :)

This patchset is to reimplement perf_config() for efficient config management.

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, 'config_set' can be reused wherever using perf_config()
and a feature of old perf_config() is the same as new perf_config()
work without the repetitive work that read the 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

v7:
- fill a missing crumb that assign NULL to 'set' variable in perf_config_set__new()
  (Arnaldo)

v6:
- add printing error message when perf_config_set__iter() is failed
- modify commit messages for bugfix 1~3 (PATCH 1/9 ~ 3/9)
  to help reviewers easily understand why them is needed

v5:
- solve the leak when perf_config_set__init() failed (Arnaldo)
  (to clear the problem it is needed to apply the bottom bugfix 1~3 patches)
- bugfix 1) fix the problem of abnormal terminaltion at perf_parse_file() called by perf_config()
- bugfix 2) if failed at collect_config(), finally free a config set
            after it is done instead of freeing the config set in the function
- bugfix 3) handle NULL pointer exception of 'set' at collect_config()

v4:
- Keep perf_config_set__delete() as it is (Arnaldo)
- Remove perf_config_set__check() (Arnaldo)
- Keep the existing code about the config set at cmd_config() (Arnaldo)

v3:
- add freeing config set after sub-command work at run_builtin() (Namhyung)
- remove needless code about the config set at cmd_config()
- add a patch about a global variable 'config_set'

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 (7):
  perf config: If collect_config() is failed, finally free a config set
    after it is done
  perf config: Use new perf_config_set__init() to initialize config set
  perf config: Add global variable 'config_set'
  perf config: Use zfree() instead of free() at
    perf_config_set__delete()
  perf config: Reimplement perf_config() using perf_config_set__iter()
  perf config: Reset the config set at only 'config' sub-command
  perf config: Reimplement show_config() using perf_config()

 tools/perf/builtin-config.c |  41 +++++-------
 tools/perf/perf.c           |   1 +
 tools/perf/util/cache.h     |   1 +
 tools/perf/util/config.c    | 147 +++++++++++++++++++++++++++++---------------
 tools/perf/util/config.h    |   4 +-
 5 files changed, 117 insertions(+), 77 deletions(-)

-- 
2.5.0

[BUGFIX][PATCH v7 1/7] perf config: If collect_config() is failed, finally free a config set after it is done

[Taeung Song]

Because of die() at perf_parse_file() a config set was freed
in collect_config(), if failed.
But it is natural to free a config set after collect_config() is done
when some problems happened.

So, in case of failure, lastly free a config set at perf_config_set__new()
instead of freeing the config set in collect_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 | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index c73f1c4..e086f59 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -643,7 +643,6 @@ static int collect_config(const char *var, const char *value,
 
 out_free:
 	free(key);
-	perf_config_set__delete(set);
 	return -1;
 }
 
@@ -653,7 +652,10 @@ struct perf_config_set *perf_config_set__new(void)
 
 	if (set) {
 		INIT_LIST_HEAD(&set->sections);
-		perf_config(collect_config, set);
+		if (perf_config(collect_config, set) < 0) {
+			perf_config_set__delete(set);
+			set = NULL;
+		}
 	}
 
 	return set;
-- 
2.5.0

[PATCH v7 2/7] 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 | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index e086f59..8749eca 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -646,13 +646,58 @@ out_free:
 	return -1;
 }
 
+static int perf_config_set__init(struct perf_config_set *set)
+{
+	int ret = -1;
+	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)) {
+		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
+			goto out;
+	}
+
+	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);
+
+out_free:
+		free(user_config);
+	}
+out:
+	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);
-		if (perf_config(collect_config, set) < 0) {
+		if (perf_config_set__init(set) < 0) {
 			perf_config_set__delete(set);
 			set = NULL;
 		}
-- 
2.5.0

[PATCH v7 3/7] perf config: Add global variable 'config_set'

[Taeung Song]

The config set is prepared by collecting
all configs from config files (i.e. user config
~/.perfconfig and system config $(sysconfdir)/perfconfig)
so the config set contains all config key-value pairs.

We need to use it as global variable to share it.
And in near future, the variable will be handled in perf_config()
and other functions at util/config.c

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 | 9 ++++-----
 tools/perf/util/config.c    | 1 +
 tools/perf/util/config.h    | 2 ++
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index fe1b77f..b3bc01a 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -62,7 +62,6 @@ static int show_config(struct perf_config_set *set)
 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,
@@ -80,8 +79,8 @@ 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) {
+	config_set = perf_config_set__new();
+	if (!config_set) {
 		ret = -1;
 		goto out_err;
 	}
@@ -92,7 +91,7 @@ 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 = show_config(config_set);
 			if (ret < 0) {
 				const char * config_filename = config_exclusive_filename;
 				if (!config_exclusive_filename)
@@ -106,7 +105,7 @@ 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(config_set);
 out_err:
 	return ret;
 }
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 8749eca..02fc6d5 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)
 {
diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
index 22ec626..ea157a4 100644
--- a/tools/perf/util/config.h
+++ b/tools/perf/util/config.h
@@ -20,6 +20,8 @@ struct perf_config_set {
 	struct list_head sections;
 };
 
+extern struct perf_config_set *config_set;
+
 struct perf_config_set *perf_config_set__new(void);
 void perf_config_set__delete(struct perf_config_set *set);
 
-- 
2.5.0

[PATCH v7 4/7] perf config: Use zfree() instead of free() at perf_config_set__delete()

[Taeung Song]

perf_config_set__delete() delete allocated the config set
but the global variable 'config_set' is used all around.

So purge and zfree by an address of the global variable
, i.e. 'struct perf_config_set **' type
instead of using local variable 'set' of which type
is 'struct perf_config_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    | 11 +++++++----
 tools/perf/util/config.h    |  2 +-
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index b3bc01a..f23fe52 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -105,7 +105,7 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 		usage_with_options(config_usage, config_options);
 	}
 
-	perf_config_set__delete(config_set);
+	perf_config_set__delete(&config_set);
 out_err:
 	return ret;
 }
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 02fc6d5..2441585 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -699,7 +699,7 @@ struct perf_config_set *perf_config_set__new(void)
 	if (set) {
 		INIT_LIST_HEAD(&set->sections);
 		if (perf_config_set__init(set) < 0) {
-			perf_config_set__delete(set);
+			perf_config_set__delete(&set);
 			set = NULL;
 		}
 	}
@@ -741,10 +741,13 @@ 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(struct perf_config_set **set)
 {
-	perf_config_set__purge(set);
-	free(set);
+	if (*set == NULL)
+		return;
+
+	perf_config_set__purge(*set);
+	zfree(set);
 }
 
 /*
diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
index ea157a4..271b429 100644
--- a/tools/perf/util/config.h
+++ b/tools/perf/util/config.h
@@ -23,6 +23,6 @@ struct perf_config_set {
 extern struct perf_config_set *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(struct perf_config_set **set);
 
 #endif /* __PERF_CONFIG_H */
-- 
2.5.0

[PATCH v7 5/7] 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 the config set that already contains all config
key-value pairs to avoid this repetitive work reading the config files
in perf_config(). (the config set mean a global variable 'config_set')

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().
And free the config set after sub-command work at run_builtin().

If we do, 'config_set' can be reused wherever using perf_config()
and a feature of old perf_config() 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/perf.c        |  1 +
 tools/perf/util/cache.h  |  1 +
 tools/perf/util/config.c | 86 +++++++++++++++++++++++-------------------------
 3 files changed, 43 insertions(+), 45 deletions(-)

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 15982ce..058d5dc 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -391,6 +391,7 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 
 	perf_env__set_cmdline(&perf_env, argc, argv);
 	status = p->fn(argc, argv, prefix);
+	perf_config_set__delete(&config_set);
 	exit_browser(status);
 	perf_env__exit(&perf_env);
 	bpf__clear();
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index 0d814bb..54bbd55 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -7,6 +7,7 @@
 #include <subcmd/pager.h>
 #include "../perf.h"
 #include "../ui/ui.h"
+#include "config.h"
 
 #include <linux/string.h>
 
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 2441585..23fb8e4 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -479,51 +479,6 @@ 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 = -1;
-	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)) {
-		if (perf_config_from_file(fn, perf_etc_perfconfig(), data) < 0)
-			goto out;
-	}
-
-	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);
-
-out_free:
-		free(user_config);
-	}
-out:
-	return ret;
-}
-
 static struct perf_config_section *find_section(struct list_head *sections,
 						const char *section_name)
 {
@@ -707,6 +662,47 @@ struct perf_config_set *perf_config_set__new(void)
 	return set;
 }
 
+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) {
+					pr_err("Error: wrong config key-value pair %s=%s\n",
+					       key, value);
+					return -1;
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
+int perf_config(config_fn_t fn, void *data)
+{
+	if (config_set == NULL)
+		config_set = perf_config_set__new();
+
+	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 v7 6/7] perf config: Reset the config set at only 'config' sub-command

[Taeung Song]

When first calling perf_config(), the config set is
initialized collecting both user and system config files
(i.e. user config ~/.perfconfig and system config
$(sysconfdir)/perfconfig) so config set contains
not only user config but also system config key-value pairs.
(User config has higher priority than system config.)

But 'config' sub-command individually use the config set
so free the existing config set (i.e. a global variable config_set)
before reinstantiating it.

And 'config' sub-command have '--user' or '--system' options.
To reinitialize with the options, the config set should be reset
at the very beginning at cmd_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/builtin-config.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index f23fe52..4dab41e 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -79,6 +79,11 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
 	else if (use_user_config)
 		config_exclusive_filename = user_config;
 
+	/*
+	 * Reset the config set at only 'config' sub-command
+	 * because of reinitializing with options config file location.
+	 */
+	perf_config_set__delete(&config_set);
 	config_set = perf_config_set__new();
 	if (!config_set) {
 		ret = -1;
-- 
2.5.0

[PATCH v7 7/7] 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 4dab41e..b6ae8ea 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;
 }
@@ -96,7 +81,7 @@ 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(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

Re: [PATCH v7 3/7] perf config: Add global variable 'config_set'

[Arnaldo Carvalho de Melo]

Em Tue, Jun 07, 2016 at 06:26:13PM +0900, Taeung Song escreveu:
> The config set is prepared by collecting
> all configs from config files (i.e. user config
> ~/.perfconfig and system config $(sysconfdir)/perfconfig)
> so the config set contains all config key-value pairs.
> 
> We need to use it as global variable to share it.

We should generally avoid global variables, and in this case, from
looking just at this patch, I'm not convinced we need to introduce more
global variables, isn't this object instantiated and deleted at the
cmd_config() function? So, can't we just pass it to any function needing
to access it?

I applied the first two patches.

- Arnaldo

> And in near future, the variable will be handled in perf_config()
> and other functions at util/config.c
> 
> 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 | 9 ++++-----
>  tools/perf/util/config.c    | 1 +
>  tools/perf/util/config.h    | 2 ++
>  3 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
> index fe1b77f..b3bc01a 100644
> --- a/tools/perf/builtin-config.c
> +++ b/tools/perf/builtin-config.c
> @@ -62,7 +62,6 @@ static int show_config(struct perf_config_set *set)
>  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,
> @@ -80,8 +79,8 @@ 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) {
> +	config_set = perf_config_set__new();
> +	if (!config_set) {
>  		ret = -1;
>  		goto out_err;
>  	}
> @@ -92,7 +91,7 @@ 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 = show_config(config_set);
>  			if (ret < 0) {
>  				const char * config_filename = config_exclusive_filename;
>  				if (!config_exclusive_filename)
> @@ -106,7 +105,7 @@ 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(config_set);
>  out_err:
>  	return ret;
>  }
> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
> index 8749eca..02fc6d5 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)
>  {
> diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
> index 22ec626..ea157a4 100644
> --- a/tools/perf/util/config.h
> +++ b/tools/perf/util/config.h
> @@ -20,6 +20,8 @@ struct perf_config_set {
>  	struct list_head sections;
>  };
>  
> +extern struct perf_config_set *config_set;
> +
>  struct perf_config_set *perf_config_set__new(void);
>  void perf_config_set__delete(struct perf_config_set *set);
>  
> -- 
> 2.5.0

Re: [PATCH v7 3/7] perf config: Add global variable 'config_set'

[Taeung Song]

Good afternoon :)

On 06/07/2016 11:05 PM, Arnaldo Carvalho de Melo wrote:
> Em Tue, Jun 07, 2016 at 06:26:13PM +0900, Taeung Song escreveu:
>> The config set is prepared by collecting
>> all configs from config files (i.e. user config
>> ~/.perfconfig and system config $(sysconfdir)/perfconfig)
>> so the config set contains all config key-value pairs.
>>
>> We need to use it as global variable to share it.
>
> We should generally avoid global variables, and in this case, from
> looking just at this patch, I'm not convinced we need to introduce more
> global variables, isn't this object instantiated and deleted at the
> cmd_config() function? So, can't we just pass it to any function needing
> to access it?

The reason why I added global variable 'config_set'
that all config key-value pairs from config files
is because of upcoming perf_config_set__delete() and perf_config().

This variable can be used not only at cmd_config()
but also at new perf_config() and future perf_config_set__delete().

Wherever new perf_config() is called, this function check
whether the global variable 'config_set' is initialized or not.
And this function use the variable 'config_set' like below.

(One of intended purposes of new perf_config() is
to avoid the repetitive work that read config files, every time
it is called and to reuse the global variable 'config_set' that
already contains all config info.)

+int perf_config(config_fn_t fn, void *data)
+{
+       if (config_set == NULL)
+               config_set = perf_config_set__new();
+
+       return perf_config_set__iter(config_set, fn, data);
+}


Finally, after sub-command finished, called perf_config_set__delete()
use the global variable as argument to free it as below.


diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 15982ce..058d5dc 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -391,6 +391,7 @@ static int run_builtin(struct cmd_struct *p, int 
argc, const char **argv)

         perf_env__set_cmdline(&perf_env, argc, argv);
         status = p->fn(argc, argv, prefix);
+       perf_config_set__delete(&config_set);
         exit_browser(status);
         perf_env__exit(&perf_env);
         bpf__clear();



Sure, we can avoid 'extern' for the global variable 'config_set'.
But IMHO, we may need to use a global variable 'config_set'
at only util/config.c at least.
(If perf_config_set__delete() don't take arguments)

(But it seems natural that we should pair between destructor
and constructor as you said.
http://marc.info/?l=linux-kernel&m=146463657721848&w=2 )

And of course, there are other way e.g.
modifying arguments of perf_config(), using perf_config_set__new()
at the very beginning at main() or etc...

Nevertheless,
if we haven't to use the global variable,
I'd find other way.

>
> I applied the first two patches.
>

Thank you!

Taeung

>
>> And in near future, the variable will be handled in perf_config()
>> and other functions at util/config.c
>>
>> 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 | 9 ++++-----
>>   tools/perf/util/config.c    | 1 +
>>   tools/perf/util/config.h    | 2 ++
>>   3 files changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
>> index fe1b77f..b3bc01a 100644
>> --- a/tools/perf/builtin-config.c
>> +++ b/tools/perf/builtin-config.c
>> @@ -62,7 +62,6 @@ static int show_config(struct perf_config_set *set)
>>   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,
>> @@ -80,8 +79,8 @@ 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) {
>> +	config_set = perf_config_set__new();
>> +	if (!config_set) {
>>   		ret = -1;
>>   		goto out_err;
>>   	}
>> @@ -92,7 +91,7 @@ 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 = show_config(config_set);
>>   			if (ret < 0) {
>>   				const char * config_filename = config_exclusive_filename;
>>   				if (!config_exclusive_filename)
>> @@ -106,7 +105,7 @@ 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(config_set);
>>   out_err:
>>   	return ret;
>>   }
>> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
>> index 8749eca..02fc6d5 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)
>>   {
>> diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
>> index 22ec626..ea157a4 100644
>> --- a/tools/perf/util/config.h
>> +++ b/tools/perf/util/config.h
>> @@ -20,6 +20,8 @@ struct perf_config_set {
>>   	struct list_head sections;
>>   };
>>
>> +extern struct perf_config_set *config_set;
>> +
>>   struct perf_config_set *perf_config_set__new(void);
>>   void perf_config_set__delete(struct perf_config_set *set);
>>
>> --
>> 2.5.0

[tip:perf/core] perf config: Constructor should free its allocated memory when failing

[tip-bot for Taeung Song]

Commit-ID:  25d8f48f78f37dd6af08bd11212ab3d53a4c8cc6
Gitweb:     http://git.kernel.org/tip/25d8f48f78f37dd6af08bd11212ab3d53a4c8cc6
Author:     Taeung Song <treeze.taeung@gmail.com>
AuthorDate: Tue, 7 Jun 2016 18:26:11 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 7 Jun 2016 10:58:55 -0300

perf config: Constructor should free its allocated memory when failing

Because of die() at perf_parse_file() a config set was freed in
collect_config(), if failed.  But it is natural to free a config set
after collect_config() is done when some problems happened.

So, in case of failure, lastly free a config set at perf_config_set__new()
instead of freeing the config set in collect_config().

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1465291577-20973-2-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/config.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index c73f1c4..e086f59 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -643,7 +643,6 @@ static int collect_config(const char *var, const char *value,
 
 out_free:
 	free(key);
-	perf_config_set__delete(set);
 	return -1;
 }
 
@@ -653,7 +652,10 @@ struct perf_config_set *perf_config_set__new(void)
 
 	if (set) {
 		INIT_LIST_HEAD(&set->sections);
-		perf_config(collect_config, set);
+		if (perf_config(collect_config, set) < 0) {
+			perf_config_set__delete(set);
+			set = NULL;
+		}
 	}
 
 	return set;

[tip:perf/core] perf config: Use new perf_config_set__init() to initialize config set

[tip-bot for Taeung Song]

Commit-ID:  8beeb00f2c8498686eee02b8edcd1488b903c90b
Gitweb:     http://git.kernel.org/tip/8beeb00f2c8498686eee02b8edcd1488b903c90b
Author:     Taeung Song <treeze.taeung@gmail.com>
AuthorDate: Tue, 7 Jun 2016 18:26:12 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 7 Jun 2016 11:01:25 -0300

perf config: Use new perf_config_set__init() to initialize config set

Instead of perf_config(), this function initializes config set by
reading various files: user config ~/.perfconfig and system config
$(sysconfdir)/perfconfig).

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

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1465291577-20973-3-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/config.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index e086f59..8749eca 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -646,13 +646,58 @@ out_free:
 	return -1;
 }
 
+static int perf_config_set__init(struct perf_config_set *set)
+{
+	int ret = -1;
+	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)) {
+		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
+			goto out;
+	}
+
+	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);
+
+out_free:
+		free(user_config);
+	}
+out:
+	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);
-		if (perf_config(collect_config, set) < 0) {
+		if (perf_config_set__init(set) < 0) {
 			perf_config_set__delete(set);
 			set = NULL;
 		}

Re: [PATCH v7 3/7] perf config: Add global variable 'config_set'

[Taeung Song]

My answer was too long..

To be short,
many sub-commands use perf_config() so
wherever new perf_config() is called,
the config set that already contains all configs from config files
should be shared.

And when a sub-command is done,
we need to free the config set at run_builtin() as below.
So, IMHO we need to use 'config_set' as a global variable.

Anyway I sent v8 recasting this patchset with other way.
(But 'config_set' is still a global variable.)

Please, reconsider it again.

Thanks,
Taeung

On 06/08/2016 12:14 AM, Taeung Song wrote:
> Good afternoon :)
>
> On 06/07/2016 11:05 PM, Arnaldo Carvalho de Melo wrote:
>> Em Tue, Jun 07, 2016 at 06:26:13PM +0900, Taeung Song escreveu:
>>> The config set is prepared by collecting
>>> all configs from config files (i.e. user config
>>> ~/.perfconfig and system config $(sysconfdir)/perfconfig)
>>> so the config set contains all config key-value pairs.
>>>
>>> We need to use it as global variable to share it.
>>
>> We should generally avoid global variables, and in this case, from
>> looking just at this patch, I'm not convinced we need to introduce more
>> global variables, isn't this object instantiated and deleted at the
>> cmd_config() function? So, can't we just pass it to any function needing
>> to access it?
>
> The reason why I added global variable 'config_set'
> that all config key-value pairs from config files
> is because of upcoming perf_config_set__delete() and perf_config().
>
> This variable can be used not only at cmd_config()
> but also at new perf_config() and future perf_config_set__delete().
>
> Wherever new perf_config() is called, this function check
> whether the global variable 'config_set' is initialized or not.
> And this function use the variable 'config_set' like below.
>
> (One of intended purposes of new perf_config() is
> to avoid the repetitive work that read config files, every time
> it is called and to reuse the global variable 'config_set' that
> already contains all config info.)
>
> +int perf_config(config_fn_t fn, void *data)
> +{
> +       if (config_set == NULL)
> +               config_set = perf_config_set__new();
> +
> +       return perf_config_set__iter(config_set, fn, data);
> +}
>
>
> Finally, after sub-command finished, called perf_config_set__delete()
> use the global variable as argument to free it as below.
>
>
> diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> index 15982ce..058d5dc 100644
> --- a/tools/perf/perf.c
> +++ b/tools/perf/perf.c
> @@ -391,6 +391,7 @@ static int run_builtin(struct cmd_struct *p, int
> argc, const char **argv)
>
>          perf_env__set_cmdline(&perf_env, argc, argv);
>          status = p->fn(argc, argv, prefix);
> +       perf_config_set__delete(&config_set);
>          exit_browser(status);
>          perf_env__exit(&perf_env);
>          bpf__clear();
>
>
>
> Sure, we can avoid 'extern' for the global variable 'config_set'.
> But IMHO, we may need to use a global variable 'config_set'
> at only util/config.c at least.
> (If perf_config_set__delete() don't take arguments)
>
> (But it seems natural that we should pair between destructor
> and constructor as you said.
> http://marc.info/?l=linux-kernel&m=146463657721848&w=2 )
>
> And of course, there are other way e.g.
> modifying arguments of perf_config(), using perf_config_set__new()
> at the very beginning at main() or etc...
>
> Nevertheless,
> if we haven't to use the global variable,
> I'd find other way.
>
>>
>> I applied the first two patches.
>>
>
> Thank you!
>
> Taeung
>
>>
>>> And in near future, the variable will be handled in perf_config()
>>> and other functions at util/config.c
>>>
>>> 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 | 9 ++++-----
>>>   tools/perf/util/config.c    | 1 +
>>>   tools/perf/util/config.h    | 2 ++
>>>   3 files changed, 7 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
>>> index fe1b77f..b3bc01a 100644
>>> --- a/tools/perf/builtin-config.c
>>> +++ b/tools/perf/builtin-config.c
>>> @@ -62,7 +62,6 @@ static int show_config(struct perf_config_set *set)
>>>   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,
>>> @@ -80,8 +79,8 @@ 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) {
>>> +    config_set = perf_config_set__new();
>>> +    if (!config_set) {
>>>           ret = -1;
>>>           goto out_err;
>>>       }
>>> @@ -92,7 +91,7 @@ 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 = show_config(config_set);
>>>               if (ret < 0) {
>>>                   const char * config_filename =
>>> config_exclusive_filename;
>>>                   if (!config_exclusive_filename)
>>> @@ -106,7 +105,7 @@ 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(config_set);
>>>   out_err:
>>>       return ret;
>>>   }
>>> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
>>> index 8749eca..02fc6d5 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)
>>>   {
>>> diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
>>> index 22ec626..ea157a4 100644
>>> --- a/tools/perf/util/config.h
>>> +++ b/tools/perf/util/config.h
>>> @@ -20,6 +20,8 @@ struct perf_config_set {
>>>       struct list_head sections;
>>>   };
>>>
>>> +extern struct perf_config_set *config_set;
>>> +
>>>   struct perf_config_set *perf_config_set__new(void);
>>>   void perf_config_set__delete(struct perf_config_set *set);
>>>
>>> --
>>> 2.5.0