Re: [RFC PATCH v4 11/15] perf stat: Handle taken alone in hardware-grouping
From: Ian Rogers
Date: Sun Mar 24 2024 - 01:24:55 EST
On Thu, Feb 8, 2024 at 7:14 PM <weilin.wang@xxxxxxxxx> wrote:
>
> From: Weilin Wang <weilin.wang@xxxxxxxxx>
>
> Add taken alone into consideration when grouping. Only one taken
> alone event is supported per group.
Is there an example of this?
> Signed-off-by: Weilin Wang <weilin.wang@xxxxxxxxx>
> ---
> tools/perf/pmu-events/jevents.py | 7 ++++++-
> tools/perf/pmu-events/pmu-events.h | 1 +
> tools/perf/util/metricgroup.c | 20 +++++++++++++++-----
> 3 files changed, 22 insertions(+), 6 deletions(-)
>
> diff --git a/tools/perf/pmu-events/jevents.py b/tools/perf/pmu-events/jevents.py
> index bc91b7efa49a..4fbb367a3228 100755
> --- a/tools/perf/pmu-events/jevents.py
> +++ b/tools/perf/pmu-events/jevents.py
> @@ -56,7 +56,9 @@ _json_event_attributes = [
> # The list of counter(s) this event could use
> 'counters',
> # Longer things (the last won't be iterated over during decompress).
> - 'long_desc'
> + 'long_desc',
> + # Taken alone event could not be collected in the same group with other taken alone event
> + 'taken_alone'
> ]
>
> # Attributes that are in pmu_unit_layout.
> @@ -355,6 +357,9 @@ class JsonEvent:
> self.num_counters = jd.get('NumCounters')
> # Number of fixed counter
> self.num_fixed_counters = jd.get('NumFixedCounters')
> + # If the event is taken alone event, which cannot be grouped with any other
> + # taken alone event.
> + self.taken_alone = jd.get('TakenAlone')
> filter = jd.get('Filter')
> self.unit = jd.get('ScaleUnit')
> self.perpkg = jd.get('PerPkg')
> diff --git a/tools/perf/pmu-events/pmu-events.h b/tools/perf/pmu-events/pmu-events.h
> index e245e4738970..837edfeb676a 100644
> --- a/tools/perf/pmu-events/pmu-events.h
> +++ b/tools/perf/pmu-events/pmu-events.h
> @@ -54,6 +54,7 @@ struct pmu_event {
> const char *unit;
> bool perpkg;
> bool deprecated;
> + bool taken_alone;
> };
>
> struct pmu_metric {
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index fe115f0880f9..95d3868819e3 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -189,6 +189,7 @@ struct metricgroup__event_info {
> /** The event uses special counters that we consider that as free counter
> * during the event grouping*/
> bool free_counter;
> + bool taken_alone;
> /** The counters the event allowed to be collected on. */
> DECLARE_BITMAP(counters, NR_COUNTERS);
> };
> @@ -235,6 +236,7 @@ struct metricgroup__group {
> DECLARE_BITMAP(fixed_counters, NR_COUNTERS);
> /** Head to the list of event names in this group*/
> struct list_head event_head;
> + bool taken_alone;
> };
>
> struct metricgroup__group_events {
> @@ -1717,6 +1719,7 @@ static void metricgroup__free_pmu_info(struct list_head *pmu_info_list)
> static struct metricgroup__event_info *event_info__new(const char *name,
> const char *pmu_name,
> const char *counter,
> + bool taken_alone,
> bool free_counter)
> {
> int ret = 0;
> @@ -1731,6 +1734,7 @@ static struct metricgroup__event_info *event_info__new(const char *name,
> pmu_name = "core";
>
> e->name = name;
> + e->taken_alone = taken_alone;
> e->free_counter = free_counter;
> e->pmu_name = pmu_name;
> if (free_counter) {
> @@ -1769,7 +1773,8 @@ static int metricgroup__add_metric_event_callback(const struct pmu_event *pe,
> if (!strcasecmp(pe->name, d->event_name)) {
> if (!pe->counters)
> return -EINVAL;
> - event = event_info__new(d->event_id, pe->pmu, pe->counters, /*free_counter=*/false);
> + event = event_info__new(d->event_id, pe->pmu, pe->counters,
> + pe->taken_alone, /*free_counter=*/false);
> if (!event)
> return -ENOMEM;
> list_add(&event->nd, d->list);
> @@ -1892,6 +1897,8 @@ static int find_and_set_counters(struct metricgroup__event_info *e,
> int ret;
> unsigned long find_bit = 0;
>
> + if (e->taken_alone && current_group->taken_alone)
> + return -ENOSPC;
> if (e->free_counter)
> return 0;
> if (e->fixed_counter) {
> @@ -1926,11 +1933,13 @@ static int _insert_event(struct metricgroup__event_info *e,
> list_add(&event->nd, &group->event_head);
> else
> list_add_tail(&event->nd, &group->event_head);
> + if (e->taken_alone)
> + group->taken_alone = true;
> return 0;
> }
>
> /**
> - * Insert the new_group node at the end of the group list.
> + * Initialize the new group and insert it to the end of the group list.
> */
> static int insert_new_group(struct list_head *head,
> struct metricgroup__group *new_group,
> @@ -1940,6 +1949,7 @@ static int insert_new_group(struct list_head *head,
> INIT_LIST_HEAD(&new_group->event_head);
> fill_counter_bitmap(new_group->gp_counters, 0, num_counters);
> fill_counter_bitmap(new_group->fixed_counters, 0, num_fixed_counters);
> + new_group->taken_alone = false;
> list_add_tail(&new_group->nd, head);
> return 0;
> }
> @@ -2143,8 +2153,8 @@ static int create_grouping(struct list_head *pmu_info_list,
> //TODO: for each new core group, we should consider to add events that uses fixed counters
> list_for_each_entry(e, event_info_list, nd) {
> bitmap_scnprintf(e->counters, NR_COUNTERS, bit_buf, NR_COUNTERS);
> - pr_debug("Event name %s, [pmu]=%s, [counters]=%s\n", e->name,
> - e->pmu_name, bit_buf);
> + pr_debug("Event name %s, [pmu]=%s, [counters]=%s, [taken_alone]=%d\n",
> + e->name, e->pmu_name, bit_buf, e->taken_alone);
> ret = assign_event_grouping(e, pmu_info_list, &groups);
> if (ret)
> goto out;
> @@ -2191,7 +2201,7 @@ static int hw_aware_build_grouping(struct expr_parse_ctx *ctx __maybe_unused,
> if (is_special_event(id)) {
> struct metricgroup__event_info *event;
>
> - event = event_info__new(id, "default_core", "0",
> + event = event_info__new(id, "default_core", "0", false,
nit: document constant arguments, so "/*taken_alone=*/false,"
Thanks,
Ian
> /*free_counter=*/true);
> if (!event)
> goto err_out;
> --
> 2.42.0
>