Re: [PATCH 2/4] perf tools: Add functions which can get or set perf config variables.

taeung
2015-05-11T02:15:38Z

Hi, Jiri Olsa

Thanks for your feedbacks on my patches.

There are one thing I don't understand very well.
I wrote a number 1) in the middle of the your feedbacks to mark it.

I don't follow, could you elaborate it little more?

On 05/05/2015 04:16 AM, Jiri Olsa wrote:
> On Mon, Apr 27, 2015 at 03:34:24PM +0900, Taeung Song wrote:
>> This patch consists of functions
>> which can get, set specific config variables.
>> For the syntax examples,
>>
>> perf config [options] [section.subkey[=value] ...]
>>
>> display key-value pairs of specific config variables
>> # perf config report.queue-size report.children
> [jolsa@krava perf]$ ./perf config krava.krava
> krava.krava=true
>
> ?
>
> some comments below
>
>> set specific config variables
>> # perf config report.queue-size=100M report.children=true
>>
>> Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
>> ---
>> tools/perf/Documentation/perf-config.txt | 2 +
>> tools/perf/builtin-config.c | 276 ++++++++++++++++++++++++++++++-
>> tools/perf/util/cache.h | 17 ++
>> tools/perf/util/config.c | 30 +++-
>> 4 files changed, 320 insertions(+), 5 deletions(-)
> SNIP
>
>> +static int set_spec_config(const char *section_name, const char *subkey,
>> + const char *value)
>> {
>> int ret = 0;
>> + ret += set_config(section_name, subkey, value);
>> + ret += perf_configset_write_in_full();
>> +
>> + return ret;
>> +}
>> +
>> +static void parse_key(const char *var, const char **section_name, const char **subkey)
>> +{
>> + char *key = strdup(var);
>> +
>> + if (!key)
>> + die("%s: strdup failed\n", __func__);
>> +
>> + *section_name = strsep(&key, ".");
>> + *subkey = strsep(&key, ".");
> should this check the config syntax? could be used for command line check as well
>> +}
>> +
>> +static int collect_config(const char *var, const char *value,
>> + void *cb __maybe_unused)
>> +{
>> + struct config_section *section_node;
>> + const char *section_name, *subkey;
> SNIP
>
>> + }
>> + for (i = 0; key[i]; i++) {
>> + if (i == 0 && !isalpha(key[i++]))
>> + goto out_err;
>> +
>> + switch (key[i]) {
>> + case '.':
>> + num_dot += 1;
>> + if (!isalpha(key[++i]))
>> + goto out_err;
>> + break;
>> + case '=':
>> + num_equals += 1;
>> + break;
>> + default:
>> + if (!isalpha(key[i]) && !isalnum(key[i]))
>> + goto out_err;
> you dont allow '-' in the key report.queue-size, I think we should support also _
>
> also please put the name checks into separated function
>
>> + }
>> + }
>> +
>> + if (num_equals > 1 || num_dot > 1)
>> + goto out_err;
>> +
>> + given_value = strchr(key, '=');
>> + if (given_value == NULL || given_value == key)
>> + given_value = NULL;
> SNIP
>
>> argc = parse_options(argc, argv, config_options, config_usage,
>> PARSE_OPT_STOP_AT_NON_OPTION);
>> + if (origin_argc > argc)
>> + is_option = true;
>> + else
>> + is_option = false;
>> +
>> + if (!is_option && argc >= 0) {
>> + switch (argc) {
>> + case 0:
>> + break;
>> + default:
>> + for (i = 0; argv[i]; i++) {
>> + value = strrchr(argv[i], '=');
>> + if (value == NULL || value == argv[i])
> hum, so you let go in args like '=krava' ?
>
> why dont you completely check the name (assignment string) first
> and decide later about the callback
>
1) I understood that the name must be completely checked first.
But I don't know the callback. What does it mean ?
Could you elaborate it little more?

Thanks,
Taeung

>> + ret = perf_configset_with_option(show_spec_config, argv[i]);
>> + else
>> + ret = perf_configset_with_option(set_spec_config, argv[i]);
>> + if (ret < 0)
>> + break;
>> + }
>> + goto out;
>> + }
>> + }
> SNIP
>
>> @@ -502,6 +501,31 @@ out:
>> return ret;
>> }
>>
>> +int perf_configset_write_in_full(void)
>> +{
>> + struct config_section *section_node;
>> + struct config_element *element_node;
>> + const char *first_line = "# this file is auto-generated.";
> so you parse whole config, change it and write back..
> hum, I dont see better way.. and I like the first line ;-)
>
>> + FILE *fp = fopen(config_file_name, "w");
>> +
>> + if (!fp)
>> + return -1;
>> +
>> + fprintf(fp, "%s\n", first_line);
>> + /* overwrite configvariables */
>> + list_for_each_entry(section_node, sections, list) {
>> + fprintf(fp, "[%s]\n", section_node->name);
>> + list_for_each_entry(element_node, &section_node->element_head, list) {
>> + if (element_node->value)
>> + fprintf(fp, "\t%s = %s\n",
>> + element_node->subkey, element_node->value);
>> + }
>> + }
>> + fclose(fp);
>> +
>> + return 0;
>> +}
>> +
>> /*
>> * Call this to report error for your variable that should not
>> * get a boolean value (i.e. "[my] var" means "true").
>> --
>> 1.9.1
>>