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

James Clark
2025-12-02T10:41:05Z

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.

It was annoying that this had to be a macro instead of a function
because ADD_CONFIG_TERM_VAL constructs the #define name of the first
argument.

It's probably worth putting in some effort to make ADD_CONFIG_CHG() a
function to avoid problems like this and maybe add a test.