Re: [PATCH 4/6] perf config: Add support for writing configs to a config file

From: Taeung Song
Date: Mon Nov 14 2016 - 12:00:49 EST

Thank you for your review.

I have a question at the very bottom
(skip v2 I sent lately or not ?).

On 11/15/2016 01:04 AM, Arnaldo Carvalho de Melo wrote:
Em Fri, Nov 04, 2016 at 03:44:20PM +0900, Taeung Song escreveu:
Add setting feature that can add config variables with their values
to a config file (i.e. user or system config file) or modify
config key-value pairs in a config file.
For the syntax examples,

perf config [<file-option>] [section.name[=value] ...]

e.g. You can set the ui.show-headers to false with

# perf config ui.show-headers=false

If you want to add or modify several config items, you can do like

# perf config annotate.show_nr_jumps=false kmem.default=slab

This works, but has some problems, see below:

Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Signed-off-by: Taeung Song <treeze.taeung@xxxxxxxxx>
---
tools/perf/builtin-config.c | 66 ++++++++++++++++++++++++++++++++++++++++-----
tools/perf/util/config.c | 6 +++++
tools/perf/util/config.h | 2 ++
3 files changed, 68 insertions(+), 6 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index fe253f3..5313702 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -17,7 +17,7 @@
static bool use_system_config, use_user_config;

static const char * const config_usage[] = {
- "perf config [<file-option>] [options] [section.name ...]",
+ "perf config [<file-option>] [options] [section.name[=value] ...]",
NULL
};

@@ -33,6 +33,37 @@ 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)
+{
+ struct perf_config_section *section = NULL;
+ struct perf_config_item *item = NULL;
+ const char *first_line = "# this file is auto-generated.";
+ FILE *fp = fopen(file_name, "w");
+
+ if (!fp)
+ return -1;
+ if (set == NULL)
+ return -1;

So, here fp is left open? I'm fixing this...

Understood. Sorry, I missed out it.

+ perf_config_set__collect(set, var, value);
+ fprintf(fp, "%s\n", first_line);
+
+ /* overwrite configvariables */
missing space?

Oops.. I missed a white space between two words.

+ perf_config_items__for_each_entry(&set->sections, section) {
+ fprintf(fp, "[%s]\n", section->name);
+
+ perf_config_items__for_each_entry(&section->items, item) {
+ if (item->value)
+ fprintf(fp, "\t%s = %s\n",
+ item->name, item->value);
+ }
+ }
+ fclose(fp);
+
+ return 0;
+}
+
static int show_spec_config(struct perf_config_set *set, const char *var)
{
struct perf_config_section *section;
@@ -82,7 +113,7 @@ static int show_config(struct perf_config_set *set)
return 0;
}

-static int parse_config_arg(char *arg, char **var)
+static int parse_config_arg(char *arg, char **var, char **value)
{
const char *last_dot = strchr(arg, '.');

@@ -99,7 +130,21 @@ static int parse_config_arg(char *arg, char **var)
return -1;
}

- *var = arg;
+ *value = strchr(arg, '=');
+ if (*value == NULL)
+ *var = arg;
+ else if (!strcmp(*value, "=")) {
+ pr_err("The config variable does not contain a value: %s\n", arg);
+ return -1;
+ } else {
+ *value = *value + 1; /* excluding a first character '=' */
+ *var = strsep(&arg, "=");
+ if (*var[0] == '\0') {
+ pr_err("invalid config variable: %s\n", arg);
+ return -1;
+ }
+ }
+

Here and..


@@ -153,7 +198,8 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
default:
if (argc) {
for (i = 0; argv[i]; i++) {
- char *var, *arg = strdup(argv[i]);
+ char *var, *value;
+ char *arg = strdup(argv[i]);

if (!arg) {
pr_err("%s: strdup failed\n", __func__);
@@ -161,13 +207,21 @@ int cmd_config(int argc, const char **argv, const char *prefix __maybe_unused)
break;
}

- if (parse_config_arg(arg, &var) < 0) {
+ if (parse_config_arg(arg, &var, &value) < 0) {
free(arg);
ret = -1;
break;
}

- ret = show_spec_config(set, var);
+ if (value == NULL)
+ ret = show_spec_config(set, var);
+ else {
+ const char *config_filename = config_exclusive_filename;
+
+ if (!config_exclusive_filename)
+ config_filename = user_config;
+ ret = set_config(set, config_filename, var, value);
+ }
free(arg);

Here, the parts are a bit different than v2 patchset I sent lately.
I refactored parse_config_arg() and a bit modify parsing
config arguments in cmd_config().

Is it better to just skip v2 patchset I sent ?
And remake new patchset regarding today your feedback ?

Or would I make v3 that adopts v2 I sent?


Thanks,
Taeung

}
} else
diff --git a/tools/perf/util/config.c b/tools/perf/util/config.c
index 18dae74..c8fb65d 100644
--- a/tools/perf/util/config.c
+++ b/tools/perf/util/config.c
@@ -602,6 +602,12 @@ static int collect_config(const char *var, const char *value,
return -1;
}

+int perf_config_set__collect(struct perf_config_set *set,
+ const char *var, const char *value)
+{
+ return collect_config(var, value, set);
+}
+
static int perf_config_set__init(struct perf_config_set *set)
{
int ret = -1;
diff --git a/tools/perf/util/config.h b/tools/perf/util/config.h
index 6f813d4..0fcdb8c 100644
--- a/tools/perf/util/config.h
+++ b/tools/perf/util/config.h
@@ -33,6 +33,8 @@ 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);
+int perf_config_set__collect(struct perf_config_set *set,
+ const char *var, const char *value);
void perf_config__init(void);
void perf_config__exit(void);
void perf_config__refresh(void);
--
2.7.4