Re: [PATCH RESEND v1 02/11] perf mem: Introduce weak function perf_mem_events__ptr()

[James Clark]

Hi Leo,

On 06/08/2020 04:07, Leo Yan wrote:
>  
>  	for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
> -		if (!perf_mem_events[j].record)
> +		e = perf_mem_events__ptr(j);
> +		if (!e->record)
>  			continue;
>  
> -		if (!perf_mem_events[j].supported) {
> +		if (!e->supported) {
>  			pr_err("failed: event '%s' not supported\n",
> -			       perf_mem_events[j].name);
> +			       perf_mem_events__name(j));
>  			free(rec_argv);
>  			return -1;

Does it make sense to do something like:

   for(j = 0; e = perf_mem_events__ptr(j); j++) {
       ...
   }

now that it's a weak function that returns NULL when the argument out of range. That way the caller
doesn't need to know about PERF_MEM_EVENTS__MAX as well and it could potentially be a different
value. I don't know if it would ever make sense to have a different number of events on different platforms?

James