Re: [RFC PATCH 14/25] perf stat: Add build string function and topdown events handling in hardware-grouping

["Liang, Kan" <kan.liang@linux.intel.com>]

On 2023-09-25 2:18 a.m., weilin.wang@intel.com wrote:
> From: Weilin Wang <weilin.wang@intel.com>
> 
> Add the function to generate final grouping strings. This function is
> very similar to the existing metricgroup__build_event_string() function.
> The difference is that the input data includes a list of grouping lists.
> 
> Topdown events need special handling because they are not included in the
> pmu-event JSON file. This should be a temporary solution to group topdown
> events. Better solution could be using JSON files to cover these events.
> 
> Signed-off-by: Weilin Wang <weilin.wang@intel.com>
> ---
>  tools/perf/util/metricgroup.c | 106 +++++++++++++++++++++++++++++++++-
>  1 file changed, 103 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index 4b1b0470d..797f831e1 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -1895,6 +1895,95 @@ static int assign_event_grouping(struct metricgroup__event_info *e,
>  	return ret;
>  }
>  
> +static int hw_aware_metricgroup__build_event_string(struct list_head *group_strs,
> +					   const char *modifier,
> +					   struct list_head *groups)
> +{
> +	struct metricgroup__pmu_group_list *p;
> +	struct metricgroup__group *g;
> +	struct metricgroup__group_events *ge;
> +	bool no_group = true;
> +	int ret = 0;
> +
> +#define RETURN_IF_NON_ZERO(x) do { if (x) return x; } while (0)
> +
> +	list_for_each_entry(p, groups, nd) {
> +		list_for_each_entry(g, &p->group_head, nd) {
> +			struct strbuf *events;
> +			struct metricgroup__group_strs *new_group_str = malloc(sizeof(struct metricgroup__group_strs));
> +
> +			if (!new_group_str)
> +				return -ENOMEM;
> +			strbuf_init(&new_group_str->grouping_str, 0);
> +			events = &new_group_str->grouping_str;
> +			ret = strbuf_addch(events, '{');
> +			RETURN_IF_NON_ZERO(ret);
> +			no_group = true;
> +			list_for_each_entry(ge, &g->event_head, nd) {
> +				const char *sep, *rsep, *id = ge->event_name;
> +
> +				pr_debug("found event %s\n", id);
> +
> +				/* Separate events with commas and open the group if necessary. */
> +				if (!no_group) {
> +					ret = strbuf_addch(events, ',');
> +					RETURN_IF_NON_ZERO(ret);
> +				}
> +				/*
> +				 * Encode the ID as an event string. Add a qualifier for
> +				 * metric_id that is the original name except with characters
> +				 * that parse-events can't parse replaced. For example,
> +				 * 'msr@tsc@' gets added as msr/tsc,metric-id=msr!3tsc!3/
> +				 */
> +				sep = strchr(id, '@');
> +				if (sep) {
> +					ret = strbuf_add(events, id, sep - id);
> +					RETURN_IF_NON_ZERO(ret);
> +					ret = strbuf_addch(events, '/');
> +					RETURN_IF_NON_ZERO(ret);
> +					rsep = strrchr(sep, '@');
> +					ret = strbuf_add(events, sep + 1, rsep - sep - 1);
> +					RETURN_IF_NON_ZERO(ret);
> +					ret = strbuf_addstr(events, ",metric-id=");
> +					RETURN_IF_NON_ZERO(ret);
> +					sep = rsep;
> +				} else {
> +					sep = strchr(id, ':');
> +					if (sep) {
> +						ret = strbuf_add(events, id, sep - id);
> +						RETURN_IF_NON_ZERO(ret);
> +					} else {
> +						ret = strbuf_addstr(events, id);
> +						RETURN_IF_NON_ZERO(ret);
> +					}
> +					ret = strbuf_addstr(events, "/metric-id=");
> +					RETURN_IF_NON_ZERO(ret);
> +				}
> +				ret = encode_metric_id(events, id);
> +				RETURN_IF_NON_ZERO(ret);
> +				ret = strbuf_addstr(events, "/");
> +				RETURN_IF_NON_ZERO(ret);
> +
> +				if (sep) {
> +					ret = strbuf_addstr(events, sep + 1);
> +					RETURN_IF_NON_ZERO(ret);
> +				}
> +				if (modifier) {
> +					ret = strbuf_addstr(events, modifier);
> +					RETURN_IF_NON_ZERO(ret);
> +				}
> +				no_group = false;
> +			}
> +			ret = strbuf_addf(events, "}:W");

We may not need :W, since the counter information has already considered
in the method.

Thanks,
Kan


> +			RETURN_IF_NON_ZERO(ret);
> +			pr_debug("events-buf: %s\n", events->buf);
> +			list_add_tail(&new_group_str->nd, group_strs);
> +		}
> +	}
> +	return ret;
> +#undef RETURN_IF_NON_ZERO
> +}
> +
>  /**
>   * create_grouping - Create a list of groups and place all the events of
>   * event_info_list into these groups.
> @@ -1906,8 +1995,8 @@ static int assign_event_grouping(struct metricgroup__event_info *e,
>   */
>  static int create_grouping(struct list_head *pmu_info_list,
>  			  struct list_head *event_info_list,
> -			  struct list_head *groupings __maybe_unused,
> -			  const char *modifier __maybe_unused)
> +			  struct list_head *groupings,
> +			  const char *modifier)
>  {
>  	int ret = 0;
>  	struct metricgroup__event_info *e;
> @@ -1923,6 +2012,7 @@ static int create_grouping(struct list_head *pmu_info_list,
>  		if (ret)
>  			goto out;
>  	}
> +	ret = hw_aware_metricgroup__build_event_string(groupings, modifier, &groups);
>  out:
>  	metricgroup__free_group_list(&groups);
>  	return ret;
> @@ -1951,9 +2041,19 @@ static int hw_aware_build_grouping(struct expr_parse_ctx *ctx __maybe_unused,
>  #define RETURN_IF_NON_ZERO(x) do { if (x) return x; } while (0)
>  	hashmap__for_each_entry(ctx->ids, cur, bkt) {
>  		const char *id = cur->pkey;
> +		const char *special_pattern = "topdown-";
>  
>  		pr_debug("found event %s\n", id);
> -
> +		if (!strncmp(id, special_pattern, strlen(special_pattern))) {
> +			struct metricgroup__event_info *event;
> +			event = event_info__new(id, "core", "0", true);
> +			if (!event) {
> +				ret = -ENOMEM;
> +				goto err_out;
> +			}
> +			list_add(&event->nd, &event_info_list);
> +			continue;
> +		}
>  		ret = get_metricgroup_events(id, etable, &event_info_list);
>  		if (ret)
>  			goto err_out;