Re: [PATCH v3 12/27] perf parse-events: Support no alias assigned event inside hybrid PMU

Jiri Olsa
2021-04-15T11:03:50Z

On Mon, Mar 29, 2021 at 03:00:31PM +0800, Jin Yao wrote:

SNIP

> ---
> v3:
> - Rename the patch:
> 'perf parse-events: Support hardware events inside PMU' -->
> 'perf parse-events: Support no alias assigned event inside hybrid PMU'
>
> - Major code is moved to parse-events-hybrid.c.
> - Refine the code.
>
> tools/perf/util/parse-events-hybrid.c | 18 +++++-
> tools/perf/util/parse-events-hybrid.h | 3 +-
> tools/perf/util/parse-events.c | 80 +++++++++++++++++++++++++--
> tools/perf/util/parse-events.h | 4 +-
> tools/perf/util/parse-events.y | 9 ++-
> tools/perf/util/pmu.c | 4 +-
> tools/perf/util/pmu.h | 2 +-
> 7 files changed, 108 insertions(+), 12 deletions(-)

please move the support to pass pmu_name and filter
on it within hybrid code in to separate patch

>
> diff --git a/tools/perf/util/parse-events-hybrid.c b/tools/perf/util/parse-events-hybrid.c
> index 8a630cbab8f3..5bf176b55573 100644
> --- a/tools/perf/util/parse-events-hybrid.c
> +++ b/tools/perf/util/parse-events-hybrid.c
> @@ -64,6 +64,11 @@ static int add_hw_hybrid(struct parse_events_state *parse_state,
> int ret;
>
> perf_pmu__for_each_hybrid_pmu(pmu) {
> + if (parse_state->pmu_name &&
> + strcmp(parse_state->pmu_name, pmu->name)) {
> + continue;

please add this check to separate function

if (pmu_cmp(parse_stat))
continue;

SNIP

> + if (!parse_state->fake_pmu && head_config && !found &&
> + perf_pmu__is_hybrid(name)) {
> + struct parse_events_term *term;
> + int ret;
> +
> + list_for_each_entry(term, head_config, list) {
> + if (!term->config)
> + continue;
> +
> + ret = parse_events__with_hybrid_pmu(parse_state,
> + term->config,
> + name, &found,
> + list);
> + if (found)
> + return ret;

what if there are more terms in head_config?
should we make sure there's just one term and fail if there's more?

also we already know the perf_pmu__is_hybrid(name) is true,
so can't we just call:

return parse_events__with_hybrid_pmu(....)

> + }
> + }
>
> if (verbose > 1) {
> fprintf(stderr, "After aliases, add event pmu '%s' with '",
> @@ -1605,6 +1630,15 @@ int parse_events_multi_pmu_add(struct parse_events_state *parse_state,
> struct perf_pmu *pmu = NULL;
> int ok = 0;
>
> + if (parse_state->pmu_name) {
> + list = malloc(sizeof(struct list_head));
> + if (!list)
> + return -1;
> + INIT_LIST_HEAD(list);
> + *listp = list;
> + return 0;
> + }

hum, why is this needed?

> +
> *listp = NULL;
> /* Add it for all PMUs that support the alias */
> list = malloc(sizeof(struct list_head));
> @@ -2176,6 +2210,44 @@ int parse_events_terms(struct list_head *terms, const char *str)
> return ret;
> }
>
> +static int list_entries_nr(struct list_head *list)
> +{
> + struct list_head *pos;
> + int n = 0;
> +
> + list_for_each(pos, list)
> + n++;
> +
> + return n;
> +}
> +
> +static int parse_events__with_hybrid_pmu(struct parse_events_state *parse_state,
> + const char *str, char *pmu_name,
> + bool *found, struct list_head *list)
> +{
> + struct parse_events_state ps = {
> + .list = LIST_HEAD_INIT(ps.list),
> + .stoken = PE_START_EVENTS,
> + .pmu_name = pmu_name,
> + .idx = parse_state->idx,
> + };

could we add this pmu_name directly to __parse_events?

it duplicates the code plus there are some extra checks
you don't do in here and which might be needed, like
last->cmdline_group_boundary setup

> + int ret;
> +
> + *found = false;
> + ret = parse_events__scanner(str, &ps);
> + perf_pmu__parse_cleanup();
> +
> + if (!ret) {
> + if (!list_empty(&ps.list)) {
> + *found = true;
> + list_splice(&ps.list, list);
> + parse_state->idx = list_entries_nr(list);

could you just use ps.idx instead of list_entries_nr ?

> + }
> + }
> +
> + return ret;
> +}
> +
> int __parse_events(struct evlist *evlist, const char *str,
> struct parse_events_error *err, struct perf_pmu *fake_pmu)
> {
> diff --git a/tools/perf/util/parse-events.h b/tools/perf/util/parse-events.h
> index c4f2f96304ce..f9d8e8e41c38 100644
> --- a/tools/perf/util/parse-events.h
> +++ b/tools/perf/util/parse-events.h
> @@ -138,6 +138,7 @@ struct parse_events_state {
> struct list_head *terms;
> int stoken;
> struct perf_pmu *fake_pmu;
> + char *pmu_name;

so it's hybrid specific, we should name it like hybrid_pmu_name or such

thanks,
jirka