Re: [BUG] jevents problem when cross building Re: [PATCH 2/3] perf tools: Allow to enable/disable events via control file

[John Garry]

On 10/12/2020 19:57, John Garry wrote:
> Hi Arnaldo,
>
> Can you try this on top:
>
> ----8<-----
>
>  From 201aa2cb7bc8723765afd84a5d3972248af0f0a1 Mon Sep 17 00:00:00 2001
> From: John Garry <john.garry@xxxxxxxxxx>
> Date: Thu, 10 Dec 2020 19:45:14 +0000
> Subject: [PATCH] perf jevents: Add system events table for empty mapping
>
> For architectures which have no PMU event lists - like arm32 - an empty
> mapping table is printed. This is how the "pmu_events_map" symbol -
> referenced in util/pmu.c::perf_pmu__find_map() - is created for those
> architectures.
>
> Since pmu-events.c now includes a new table - "pmu_sys_event_tables" -
> which is also referenced from util/pmu.c, also add this for the empty
> mappings.
>
> Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
>
> diff --git a/tools/perf/pmu-events/jevents.c 
> b/tools/perf/pmu-events/jevents.c
> index e930096ad713..28e20d9ec0f5 100644
> --- a/tools/perf/pmu-events/jevents.c
> +++ b/tools/perf/pmu-events/jevents.c
> @@ -816,19 +816,30 @@ static void print_mapping_test_table(FILE *outfp)
>       fprintf(outfp, "},\n");
>   }
>
> +static void print_system_event_mapping_table_prefix(FILE *outfp)
> +{
> +    fprintf(outfp, "\nstruct pmu_sys_events pmu_sys_event_tables[] = {");
> +}
> +
> +static void print_system_event_mapping_table_suffix(FILE *outfp)
> +{
> +    fprintf(outfp, "\n\t{\n\t\t.table = 0\n\t},");
> +
> +    fprintf(outfp, "\n};\n");
> +}
> +
>   static int process_system_event_tables(FILE *outfp)
>   {
>       struct sys_event_table *sys_event_table;
>
> -    fprintf(outfp, "\nstruct pmu_sys_events pmu_sys_event_tables[] = {");
> +    print_system_event_mapping_table_prefix(outfp);
>
>       list_for_each_entry(sys_event_table, &sys_event_tables, list) {
>           fprintf(outfp, "\n\t{\n\t\t.table = %s,\n\t},",
>               sys_event_table->soc_id);
>       }
> -    fprintf(outfp, "\n\t{\n\t\t.table = 0\n\t},");
>
> -    fprintf(outfp, "\n};\n");
> +    print_system_event_mapping_table_suffix(outfp);
>
>       return 0;
>   }
> @@ -938,6 +949,9 @@ static void create_empty_mapping(const char 
> *output_file)
>       fprintf(outfp, "#include \"pmu-events/pmu-events.h\"\n");
>       print_mapping_table_prefix(outfp);
>       print_mapping_table_suffix(outfp);
> +    print_system_event_mapping_table_prefix(outfp);
> +    print_system_event_mapping_table_suffix(outfp);
> +
>       fclose(outfp);
>   }
>
> ---->8----
>
> Obviously I never tested building for one of test architectures which 
> does not use PMU events - sorry!

Hi Arnaldo,

Just wondering if you have had any more problems here? Shall I send a 
formal patch? I tested that change and it looked ok.

Thanks,
John