Re: [PATCH v2 2/2] perf jevents: Autogenerate empty-pmu-events.c

[John Garry]

On 25/05/2024 02:30, Ian Rogers wrote:
> empty-pmu-events.c exists so that builds may occur without python
> being installed on a system. > Manually updating empty-pmu-events.c to
> be in sync with jevents.py is a pain, let's use jevents.py to generate
> empty-pmu-events.c.
>
> 1) change jevents.py so that an arch and model of none cause
>     generation of a pmu-events.c without any json. Add a SPDX and
>     autogenerated warning to the start of the file.
>
> 2) change Build so that if a generated pmu-events.c for arch none and
>     model none doesn't match empty-pmu-events.c the build fails with a
>     cat of the differences. Update Makefile.perf to clean up the files
>     used for this.
>
> 3) update empty-pmu-events.c to match the output of jevents.py with
>     arch and mode of none.
>
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>


Reviewed-by: John Garry <john.g.garry@xxxxxxxxxx>

> ---
>   tools/perf/Makefile.perf                 |   2 +
>   tools/perf/pmu-events/Build              |  12 +-
>   tools/perf/pmu-events/empty-pmu-events.c | 894 ++++++++++++++---------
>   tools/perf/pmu-events/jevents.py         |   6 +-
>   4 files changed, 562 insertions(+), 352 deletions(-)
>
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.per

..

> -	},
> +struct pmu_table_entry {
> +        const struct compact_pmu_event *entries;
> +        uint32_t num_entries;
> +        struct compact_pmu_event pmu_name;
> +};
> +
> +static const char *const big_c_string =
> +/* offset=0 */ "default_core\000"
> +/* offset=13 */ "bp_l1_btb_correct\000branch\000L1 BTB Correction\000event=0x8a\000\00000\000\000"
> +/* offset=72 */ "bp_l2_btb_correct\000branch\000L2 BTB Correction\000event=0x8b\000\00000\000\000"

Please remind me: how to figure out this number when adding a new entry?

> +/* offset=131 */ "l3_cache_rd\000cache\000L3 cache access, read\000event=0x40\000\00000\000Attributable Level 3 cache access, read\000"