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 <hemant@xxxxxxxxxxxxxxxxxx>
> > ---
> >   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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