Re: [PATCH v2 07/11] perf vendor events: add support for arch standard events

[John Garry]

On 27/02/2018 09:48, Jiri Olsa wrote:
> On Sat, Feb 24, 2018 at 12:05:28AM +0800, John Garry wrote:
>
> SNIP
>
> > +static int save_arch_std_events(void *data, char *name, char *event,
> > +				char *desc, char *long_desc, char *pmu,
> > +				char *unit, char *perpkg, char *metric_expr,
> > +				char *metric_name, char *metric_group)
> > +{
> > +	struct event_struct *es;
> > +	struct stat *sb = data;
> > +
> > +	es = malloc(sizeof(*es));
> > +	if (!es)
> > +		return -ENOMEM;
> > +	memset(es, 0, sizeof(*es));
> > +	FOR_ALL_EVENT_STRUCT_FIELDS(ADD_EVENT_FIELD);
> > +	list_add_tail(&es->list, &arch_std_events);
> > +	return 0;
> > +out_free:
> > +	FOR_ALL_EVENT_STRUCT_FIELDS(FREE_EVENT_FIELD);
> > +	free(es);
> > +	return -ENOMEM;
> > +}
> > +
> >  static void print_events_table_suffix(FILE *outfp)
> >  {
> >  	fprintf(outfp, "{\n");
> > @@ -391,6 +469,27 @@ static char *real_event(const char *name, char *event)
> >  	return event;
> >  }
> >
> > +static int
> > +try_fixup(const char *fn, char *arch_std, char **event, char **desc,
> > +	  char **name, char **long_desc, char **pmu, char **filter,
> > +	  char **perpkg, char **unit, char **metric_expr, char **metric_name,
> > +	  char **metric_group)
> > +{
> > +	/* try to find matching event from arch standard values */
> > +	struct event_struct *es;
> > +
> > +	list_for_each_entry(es, &arch_std_events, list) {
> > +		if (!strcmp(arch_std, es->event+sizeof(EVENT_PREFIX))) {
>
> I spent some time figuring out how this can work when there's on '=' in EVENT_PREFIX
> is this because sizeof returns +1 size for NULL char also?

Right, sizeof(EVENT_PREFIX)=6 strlen(EVENT_PREFIX)=5

EVENT_PREFIX is "event"

Thank you,
John

> thanks,
> jirka
>
> .