Re: [PATCH v10 2/3] perf config: Reimplement perf_config() introducing new perf_config_init() and perf_config_finish()

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

Hi, Arnaldo :)

On 06/23/2016 08:56 PM, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jun 23, 2016 at 05:55:18PM +0900, Taeung Song escreveu:
>> Many sub-commands use perf_config() but
>> everytime perf_config() is called, perf_config() always read config files.
>> (i.e. user config '~/.perfconfig' and system config '$(sysconfdir)/perfconfig')
>>
>> But it is better 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 static variable 'config_set')
>>
>> In other words, if new perf_config_init() is called,
>> only first time 'config_set' is initialized collecting all configs from the config files.
>> And then we could use new perf_config() like old perf_config().
>> When a sub-command finished, free the config set by perf_config_finish() at run_builtin().
>>
>> If we do, 'config_set' can be reused wherever perf_config() is called
>> and a feature of old perf_config() is the same as new perf_config() work
>> without the repetitive work that read the config files.
>>
>> In summary, in order to use features about configuration,
>> we can call the functions at perf.c and other source files as below.
>>
>>      # initialize a config set
>>      perf_config_init()
>>
>>      # configure actual variables from a config set
>>      perf_config()
>>
>>      # eliminate allocated config set
>>      perf_config_finish()
>>
>>      # destroy existing config set and initialize a new config set.
>>      perf_config_refresh()
>>
>> 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/builtin-config.c |  4 ++
>>   tools/perf/perf.c           |  2 +
>>   tools/perf/util/config.c    | 92 +++++++++++++++++++++++----------------------
>>   tools/perf/util/config.h    | 29 ++++++++++++++
>>   4 files changed, 82 insertions(+), 45 deletions(-)
>>
>> diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
>> index fe1b77f..cfd1036 100644
>> --- a/tools/perf/builtin-config.c
>> +++ b/tools/perf/builtin-config.c
>> @@ -80,6 +80,10 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
>>   	else if (use_user_config)
>>   		config_exclusive_filename = user_config;
>>
>> +	/*
>> +	 * At only 'config' sub-command, individually use the config set
>> +	 * because of reinitializing with options config file location.
>> +	 */
>>   	set = perf_config_set__new();
>>   	if (!set) {
>>   		ret = -1;
>> diff --git a/tools/perf/perf.c b/tools/perf/perf.c
>> index 66772da..280967e 100644
>> --- a/tools/perf/perf.c
>> +++ b/tools/perf/perf.c
>> @@ -355,6 +355,7 @@ 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_finish();
>>   	exit_browser(status);
>>   	perf_env__exit(&perf_env);
>>   	bpf__clear();
>> @@ -522,6 +523,7 @@ int main(int argc, const char **argv)
>>
>>   	srandom(time(NULL));
>>
>> +	perf_config_init();
>>   	perf_config(perf_default_config, NULL);
>>   	set_buildid_dir(NULL);
>>
>> diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
>> index d15c592..a16f95d 100644
>> --- a/tools/perf/util/config.c
>> +++ b/tools/perf/util/config.c
>> @@ -26,6 +26,7 @@ static FILE *config_file;
>>   static const char *config_file_name;
>>   static int config_linenr;
>>   static int config_file_eof;
>> +static struct perf_config_set *config_set;
>>
>>   const char *config_exclusive_filename;
>>
>> @@ -478,51 +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)
>>   {
>> @@ -706,6 +662,52 @@ struct perf_config_set *perf_config_set__new(void)
>>   	return set;
>>   }
>>
>> +int perf_config(config_fn_t fn, void *data)
>> +{
>> +	int ret = 0;
>> +	char key[BUFSIZ];
>> +	struct perf_config_section *section;
>> +	struct perf_config_item *item;
>> +
>> +	if (config_set == NULL)
>> +		return -1;
>> +
>> +	config_set__for_each(config_set, section, item) {
>> +		char *value = item->value;
>> +
>> +		if (value) {
>> +			scnprintf(key, sizeof(key), "%s.%s",
>> +				  section->name, item->name);
>> +			ret = fn(key, value, data);
>> +			if (ret < 0) {
>> +				pr_err("Error: wrong config key-value pair %s=%s\n",
>> +				       key, value);
>> +				break;
>> +			}
>> +		}
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +void perf_config_init(void)
>> +{
>> +	if (config_set == NULL)
>> +		config_set = perf_config_set__new();
>> +}
>> +
>> +void perf_config_finish(void)
>> +{
>> +	perf_config_set__delete(config_set);
>> +	config_set = NULL;
>> +}
>> +
>> +void perf_config_refresh(void)
>> +{
>> +	perf_config_finish();
>> +	perf_config_init();
>> +}
>> +
>>   static void perf_config_item__delete(struct perf_config_item *item)
>>   {
>>   	zfree(&item->name);
>> diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
>> index 155a441..746c619 100644
>> --- a/tools/perf/util/config.h
>> +++ b/tools/perf/util/config.h
>> @@ -33,5 +33,34 @@ const char *perf_etc_perfconfig(void);
>>
>>   struct perf_config_set *perf_config_set__new(void);
>>   void perf_config_set__delete(struct perf_config_set *set);
>> +void perf_config_init(void);
>> +void perf_config_finish(void);
>> +void perf_config_refresh(void);
>
> Please use double _ to separate the subsystem/class from its methods,
> i.e.:
>
> void perf_config__init(void);
> void perf_config__finish(void);
> void perf_config__refresh(void);

I got it :)

>> +
>> +/**
>> + * config_sections__for_each - iterate thru all the sections
>> + * @list: list_head instance to iterate
>> + * @section: struct perf_config_section iterator
>> + */
>> +#define config_sections__for_each(list, section)	\
>> +        list_for_each_entry(section, list, node)
>
> These macros operate on perf_config_sections, so please name it
> accordingly, i.e.:
> 	perf_config_sections__for_each()
>
>> +
>> +/**
>> + * config_items__for_each - iterate thru all the items
>> + * @list: list_head instance to iterate
>> + * @item: struct perf_config_item iterator
>> + */
>> +#define config_items__for_each(list, item)	\
>> +        list_for_each_entry(item, list, node)
>> +
>
> Ditto
>
>> +/**
>> + * config_set__for_each - iterate thru all the config section-item pairs
>> + * @set: evlist instance to iterate
>> + * @section: struct perf_config_section iterator
>> + * @item: struct perf_config_item iterator
>> + */
>> +#define config_set__for_each(set, section, item)			\
>> +	config_sections__for_each(&set->sections, section)		\
>> +	config_items__for_each(&section->items, item)
>
> Ditto.
>

Granted.

I'll send v11 soon with this change!

Thanks,
Taeung