Re: [PATCH v2 4/5] perf/sdt: Delete SDT events from cache

[Hemant Kumar]

On 10/07/2014 08:47 AM, Namhyung Kim wrote:

On Wed, 01 Oct 2014 08:18:41 +0530, Hemant Kumar wrote:

This patch adds the support to delete SDT events from the cache.
To delete an event corresponding to a file, first the cache is read into
the file_hash list. The key is calculated from the file name.
And then, the file_list for that file_hash entry is traversed to find out
the target file_list entry. Once, it is found, its contents are all freed up.

# ./perf sdt-cache --del /usr/lib64/libc-2.16.so

8 events removed for /usr/lib64/libc-2.16.so!

Signed-off-by: Hemant Kumar <hem...@linux.vnet.ibm.com>
---
  tools/perf/builtin-sdt-cache.c |   28 +++++++++++++++++++++++++++-
  tools/perf/util/parse-events.h |    1 +
  tools/perf/util/sdt.c          |   35 +++++++++++++++++++++++++++++++++++
  3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-sdt-cache.c b/tools/perf/builtin-sdt-cache.c
index 5faf8e5..12276da 100644
--- a/tools/perf/builtin-sdt-cache.c
+++ b/tools/perf/builtin-sdt-cache.c
@@ -16,6 +16,7 @@
  /* Session management structure */
  static struct {
        bool add;
+       bool del;
        bool dump;
        const char *target;
  } params;
@@ -29,6 +30,15 @@ static int opt_add_sdt_events(const struct option *opt 
__maybe_unused,
        return 0;
  }

+static int opt_del_sdt_events(const struct option *opt __maybe_unused,

+                             const char *str, int unset __maybe_unused)
+{
+       params.del = true;
+       params.target = str;
+
+       return 0;
+}
+
  static int opt_show_sdt_events(const struct option *opt __maybe_unused,
                               const char *str, int unset __maybe_unused)
  {
@@ -45,13 +55,17 @@ int cmd_sdt_cache(int argc, const char **argv, const char 
*prefix __maybe_unused
                OPT_CALLBACK('a', "add", NULL, "filename",
                             "add SDT events from a file.",
                             opt_add_sdt_events),
+               OPT_CALLBACK('d', "del", NULL, "filename",
+                            "Remove SDT events corresponding to a file from 
the"
+                            " sdt cache.",
+                            opt_del_sdt_events),
                OPT_CALLBACK_NOOPT('s', "dump", NULL, "show SDT events",
                                   "Read SDT events from cache and display.",
                                   opt_show_sdt_events),
                OPT_END()
        };
        const char * const sdt_cache_usage[] = {
-               "perf sdt_cache [--add filename | --dump]",
+               "perf sdt_cache [--add filename | --del filename | --dump]",

I think it'd be better split the usage into two lines:

                "perf sdt_cache [--add | --del] <filename>"
                "perf sdt_cache --dump"

Nice suggestion. Will change that.

                NULL
        };

@@ -63,6 +77,10 @@ int cmd_sdt_cache(int argc, const char **argv, const char *prefix __maybe_unused symbol__elf_init();

        if (params.add) {
+               if (params.del) {
+                       pr_err("Error: Don't use --del with --add\n");
+                       usage_with_options(sdt_cache_usage, sdt_cache_options);
+               }
                if (params.dump) {
                        pr_err("Error: Don't use --dump with --add\n");
                        usage_with_options(sdt_cache_usage, sdt_cache_options);
@@ -70,6 +88,14 @@ int cmd_sdt_cache(int argc, const char **argv, const char 
*prefix __maybe_unused
                ret = add_sdt_events(params.target);
                if (ret < 0)
                        pr_err("Cannot add SDT events to cache!\n");
+       } else if (params.del) {
+               if (params.dump) {
+                       pr_err("Error: Don't use --dump with --del\n");
+                       usage_with_options(sdt_cache_usage, sdt_cache_options);
+               }
+               ret = remove_sdt_events(params.target);
+               if (ret < 0)
+                       pr_err("Cannot remove SDT events from cache!\n");
        } else if (params.dump) {
                if (argc == 0) {
                        ret = dump_sdt_events();

I think we need to a flag for exclusive options so that it can emit
warnings like this automatically during option parsing.

Ok.

Thanks,
Namhyung

[...]

--
Thanks,
Hemant Kumar

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