[PATCH v4 13/17] perf pmu-events: Don't assume pmu_event is an array
John Garry
john.garry at huawei.com
Fri Aug 5 05:56:04 PDT 2022
On 04/08/2022 23:18, Ian Rogers wrote:
> Current code assumes that a struct pmu_event can be iterated over
> forward until a NULL pmu_event is encountered. This makes it difficult
> to refactor pmu_event. Add a loop function taking a callback function
> that's passed the struct pmu_event. This way the pmu_event is only
> needed for one element and not an entire array.
>
> Switch existing code iterating over the pmu_event arrays to use the new
> loop function pmu_events_table_for_each_event.
I find it hard to follow the change from the description. The title is
"Don't assume pmu_event is an array", but that is rightly what
pmu_events_table_for_each_event() does.
If I check - for exmaple - pmu_add_cpu_aliases_map(), you just switch it
over to using pmu_events_table_for_each_event(), which seems resonable.
So it just seems here that we're refactoring the code, and not changing
the nature of how we handle pmu_events *.
>
> Signed-off-by: Ian Rogers <irogers at google.com>
> ---
> tools/perf/pmu-events/empty-pmu-events.c | 34 +++--
> tools/perf/pmu-events/jevents.py | 34 +++--
> tools/perf/pmu-events/pmu-events.h | 3 +
> tools/perf/tests/pmu-events.c | 136 +++++++++--------
> tools/perf/util/metricgroup.c | 181 ++++++++++++++++-------
> tools/perf/util/pmu.c | 65 ++++----
> tools/perf/util/s390-sample-raw.c | 42 ++++--
> 7 files changed, 313 insertions(+), 182 deletions(-)
>
> diff --git a/tools/perf/pmu-events/empty-pmu-events.c b/tools/perf/pmu-events/empty-pmu-events.c
> index 028f44efe48d..bee1967baa2b 100644
> --- a/tools/perf/pmu-events/empty-pmu-events.c
> +++ b/tools/perf/pmu-events/empty-pmu-events.c
> @@ -247,6 +247,20 @@ static const struct pmu_sys_events pmu_sys_event_tables[] = {
> },
> };
>
> +int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
> + void *data)
> +{
> + for (const struct pmu_event *pe = &table[0];
> + pe->name || pe->metric_group || pe->metric_name;
> + pe++) {
> + int ret = fn(pe, table, data);
> +
> + if (ret)
> + return ret;
> + }
> + return 0;
> +}
> +
> const struct pmu_event *perf_pmu__find_table(struct perf_pmu *pmu)
> {
> const struct pmu_event *table = NULL;
> @@ -291,14 +305,10 @@ int pmu_for_each_core_event(pmu_event_iter_fn fn, void *data)
> for (const struct pmu_events_map *tables = &pmu_events_map[0];
> tables->table;
> tables++) {
> - for (const struct pmu_event *pe = &tables->table[0];
> - pe->name || pe->metric_group || pe->metric_name;
> - pe++) {
> - int ret = fn(pe, &tables->table[0], data);
> + int ret = pmu_events_table_for_each_event(tables->table, fn, data);
>
> - if (ret)
> - return ret;
> - }
> + if (ret)
> + return ret;
> }
> return 0;
> }
> @@ -319,14 +329,10 @@ int pmu_for_each_sys_event(pmu_event_iter_fn fn, void *data)
> for (const struct pmu_sys_events *tables = &pmu_sys_event_tables[0];
> tables->name;
> tables++) {
> - for (const struct pmu_event *pe = &tables->table[0];
> - pe->name || pe->metric_group || pe->metric_name;
> - pe++) {
> - int ret = fn(pe, &tables->table[0], data);
> + int ret = pmu_events_table_for_each_event(tables->table, fn, data);
>
> - if (ret)
> - return ret;
> - }
> + if (ret)
> + return ret;
> }
> return 0;
> }
> diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
> index e976c5e8e80b..365c960202b0 100755
> --- a/tools/perf/pmu-events/jevents.py
> +++ b/tools/perf/pmu-events/jevents.py
> @@ -409,6 +409,20 @@ static const struct pmu_sys_events pmu_sys_event_tables[] = {
> \t},
> };
>
> +int pmu_events_table_for_each_event(const struct pmu_event *table, pmu_event_iter_fn fn,
> + void *data)
Again we seem to be just duplicating what is in empty-pmu-events.c - can
we avoid this? another idea (apart from linking in other c files) is for
empty-pmu-events.c to be generated from jevents.py (like how it was done
for jevents.c)
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