Re: [PATCH 1/7] perf tools: Track all user changed config bits

Leo Yan
2025-12-02T12:36:11Z

On Tue, Dec 02, 2025 at 11:21:47AM +0000, Coresight ML wrote:
> On Tue, Dec 02, 2025 at 10:40:49AM +0000, James Clark wrote:
> >
> >
> > On 02/12/2025 10:15 am, Leo Yan wrote:
> > > On Mon, Dec 01, 2025 at 04:41:04PM +0000, Coresight ML wrote:
> > >
> > > [...]
> > >
> > > > +#define ADD_CONFIG_CHG(format_type, term_type, new_term) \
> > > > +{ \
> > > > + struct parse_events_term *term; \
> > > > + u64 bits = 0; \
> > > > + int type; \
> > > > + \
> > > > + list_for_each_entry(term, &head_config->terms, list) { \
> > > > + if (term->type_term == PARSE_EVENTS__TERM_TYPE_USER) { \
> > > > + type = perf_pmu__format_type(pmu, term->config);\
> > > > + if (type != format_type) \
> > > > + continue; \
> > > > + bits |= perf_pmu__format_bits(pmu, term->config); \
> > > > + } else if (term->type_term == term_type) { \
> > > > + bits = ~(u64)0; \
> > > > + } \
> > > > + } \
> > > > + \
> > > > + if (bits) \
> > > > + ADD_CONFIG_TERM_VAL(new_term, cfg_chg, bits, false); \
> > > > + return 0; \
> > >
> > > Nitpick: "return 0" is not needed here. Otherwise:
> > >
> > > Reviewed-by: Leo Yan <leo.yan@arm.com>
> >
> > I think it's worse than not needed, it makes it stop collecting the changes
> > after the first one.
>
> Just curious how this can happen.
>
> foo()
> {
> {
> chunk 1;
> }
>
> {
> chunk 2;
> }
> }
>
> Seem to me, if without "return 0" in chunk 1, it still can continue to
> run chunk 2, no?

Please ignore my question above. We need to iterate from config to
config4, if return 0 when handling config, then never add other
configs?

Thanks,
Leo