Re: [PATCH v2 2/4] perf config: Finally write changed configs on config file at a time

[Taeung Song]

On 05/09/2017 01:37 AM, Arnaldo Carvalho de Melo wrote:

Em Mon, May 08, 2017 at 08:07:40PM +0900, Taeung Song escreveu:

Currently set_config() can be repeatedly called for each
input config on the below case:

  $ perf config kmem.default=slab report.children=false ...

But it's a waste, so finally write changed configs at a time.

Cc: Jiri Olsa <jo...@kernel.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Signed-off-by: Taeung Song <treeze.tae...@gmail.com>
---
 tools/perf/builtin-config.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-config.c b/tools/perf/builtin-config.c
index 7545966..0d38599 100644
--- a/tools/perf/builtin-config.c
+++ b/tools/perf/builtin-config.c
@@ -33,8 +33,7 @@ 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)
+static int set_config(struct perf_config_set *set, const char *file_name)
 {
        struct perf_config_section *section = NULL;
        struct perf_config_item *item = NULL;
@@ -48,7 +47,6 @@ static int set_config(struct perf_config_set *set, const char 
*file_name,
        if (!fp)
                return -1;

-       perf_config_set__collect(set, file_name, var, value);
        fprintf(fp, "%s\n", first_line);

        /* overwrite configvariables */
@@ -160,6 +158,7 @@ int cmd_config(int argc, const char **argv)
        struct perf_config_set *set;
        char *user_config = mkpath("%s/.perfconfig", getenv("HOME"));
        const char *config_filename;
+       bool changed = false;

        argc = parse_options(argc, argv, config_options, config_usage,
                             PARSE_OPT_STOP_AT_NON_OPTION);
@@ -227,10 +226,16 @@ int cmd_config(int argc, const char **argv)

                        if (value == NULL)
                                ret = show_spec_config(set, var);
-                       else
-                               ret = set_config(set, config_filename, var, 
value);
+                       else {
+                               perf_config_set__collect(set, config_filename,
+                                                        var, value);
+                               changed = true;
+                       }
                        free(arg);
                }
+
+               if (changed)
+                       ret = set_config(set, config_filename);

Ok, this improves the situation, even fixing what seems like a bug, i.e.
that ret variable set in the if (value == NULL) case is not being
checked, the look just goes on to completion and whatever is the last
value left in 'ret' is what will be returned by cmd_config()...

I think we should fix that bug first, making it exit the loop and
perhaps show some error message, then do this 'call set_config()' only
at the end', no?

I understood !
will fix the bug you mentioned first,
before this patch.

I applied the first patch, the one just renesting things.

- Arnaldo

Thank you !,
Taeung

        }

        perf_config_set__delete(set);
--
2.7.4