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

Leo Yan leo.yan at arm.com
Tue Dec 2 04:36:00 PST 2025


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 at 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



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